Rain Water Harvesting and Geostatistical Modelling of Ground Water in and around ISM Campus Dhanbad
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Transcript of Rain Water Harvesting and Geostatistical Modelling of Ground Water in and around ISM Campus Dhanbad
Rain Water Harvesting and Geostatistical Modelling of
Ground Water in and around ISM Campus Dhanbad,
Jharkhand
Dissertation Submitted
IN PARTIAL FULFILLMENT OF THE REQUIREMENT
FOR THE AWARD OF THE DEGREE OF
MASTER OF TECHNOLOGY
IN
MINERAL EXPLORATION
Submitted by
Dhirendra Pratap Singh
Admission No. 2013MT0359
UNDER THE GUIDANCE OF
Prof. B.C. Sarkar
Department of Applied Geology
DEPARTMENT OF APPLIED GEOLOGY
INDIAN SCHOOL OF MINES
DHANBAD- 826004
MAY-2015
INDIAN SCHOOL OF MINES
DHANBAD-826004, JHARKHAND, INDIA
(Declared as Deemed-to-be-University U/S 3 of the UGC Act, 1956 vide
Notification No. F11-4/67-U3, dated 18.9.1967 of Govt. of India)
DECLARATION
This thesis is a presentation of my original research work. Wherever contributions of others
are involved, every effort is made to indicate this clearly, with due reference to the literature,
and acknowledgement of collaborative research and discussions. I further state that no part of
the thesis and its data will be published without the consent of my guides.
The dissertation work has been carried out under the guidance of Prof. B.C. Sarkar and Dr.
S.C. Dhiman at the Indian School of Mines, Dhanbad.
Dhirendra Pratap Singh
M.Tech (Mineral Exploration)
Admn No: 2013MT0359
1926सेराष्ट्रकीसेवामें In the service of Nation Since 1926 .
Phone: (0326) 2296-559 to 562 (4 Lines); Fax: (0326) 2296563, Website: www.ismdhanbad.ac.in
Keep your Environment Clean & Green
Acknowledgement
I am extremely fortunate to be involved in an exciting and challenging project on “Rain Water
Harvesting and Geostatistical Modelling of Ground Water in and around ISM Campus
Dhanbad, Jharkhand”. It has enriched my life, giving me an opportunity to look at the
horizon of technology with a wide view and to come in contact with people endowed with
many superior qualities.
I would like to express my deep gratitude and respect to my guide Prof. B.C. Sarkar,
Department of Applied Geology for his excellent guidance, suggestions and constructive
criticism. I feel proud that I am one of his post graduate students. The guidance of Dr. S.C.
Dhiman has been extremely helpful to enhance my knowledge that created a permanent storage
in my mind. I consider myself extremely lucky to be able to work under the guidance of such
a dynamic personalities. Whenever I faced any problem – academic or otherwise, I approached
him, and he was always there, with his reassuring smile, to bail me out.
I also like to convey my special thanks to Dr. A.K. Prasad, Associate Professor for his
immense support and guide, Mr Shailendra Nath Dwivedi, Sr. Scientist, CGWB, Dr. S.
Sarangi, Associate Professor & Coordinator, Mineral Exploration and Prof. Atul Kumar
Verma, Head of Department, Applied Geology for providing excellent support and
cooperation.
I am also very thankful to my friends Rahul, Sarmistha, Snigdha, Nirasindhu and Girija and
Shri Ajay Bhattacharya for their help and support.
I would also like to extend my sincere thanks to all the staff members of Applied Geology
Department, ISM, Dhanbad and CGWB scientists for their valuable suggestions and timely
support. I am really grateful to my loving parents for their perseverance, encouragement with
support of all kinds and their unconditional affection. This thesis is a fruit of the fathomless
love and affection of all the people around me – my parents, my supervisor and my friends so
the credit goes entirely to them.
Dhirendra Pratap Singh
M.Tech (Mineral Exploration)
Admn No: 2013MT0359
Abstract
Groundwater plays a pivotal role in the society and its limited resource needs to be
conserved and managed vis-à-vis its requirements for sustainable development. Artificial
recharge, a technique for augmentation of groundwater resources, diverts surface water into
subsurface aquifers by constructing various recharge structures. Augmenting recharge to
groundwater leads to rise in groundwater levels, improvement in water supply, saving in energy
costs for pumping, improvement in water quality and environment, and above all, sustainability
of groundwater resources. The technique has become important mainly because of increasing
demand of groundwater owing primarily due to population growth. Rainwater harvesting and
artificial recharge is thus important to augment and conserve groundwater resource for
effective management.
Spatial variability phenomena of groundwater level in the study area for pre-monsoon
and post-monsoon periods have been analysed and modelled individually and that of the
fluctuation between pre- and post-monsoon. The spatial variability analyses revealed
experimental semi-variograms with moderately low nugget effect and increasing tendency of
semi-variogram values with constantly increasing distances and levelling off at respective
range of influences. Point Kriging Cross-Validation technique has been used for fitting a
mathematical model to experimental semi-variograms. This is followed by construction of
block grid cells of 25 m x 25 m for which kriged estimate and kriging standard deviation values
have been arrived at employing Ordinary Kriging to estimate the rise in the rainwater harvested
groundwater level during the year 2014. The modelling study led to generation of kriged
estimate and kriged standard deviation spatial distribution maps in respect of pre-monsoon,
post-monsoon and the fluctuation for the year 2014. The study revealed a mean rise of 2.29m
in the groundwater level owing to the rainwater harvesting. The rise in the groundwater level
during the study period have led to an estimate of groundwater resource to 144,270,000 litres as
compared to the consumption of 703,440,000 litres. The study estimated that about 83% of total volume
of groundwater available is consumed and thereby maintaining a balance of about 17%. This figure of
groundwater resource balance is expected to improve over the years with continued monitoring study
of the fluctuating trend of the groundwater level with implementation of rainwater harvesting and
artificial recharge in the campus. Similar rainwater harvesting study can be of use in other areas
for assessing spatial and temporal phenomena leading to the usefulness of geostatistical
modelling for sustainable development and management of groundwater resource.
Similar rain water harvesting study can be of use in other areas for assessing spatio-temporal
phenomena leading to the usefulness of geostatistical methods for sustainable development and
management of groundwater resource.
Keywords: Rainwater harvesting, groundwater level, spatial variability, point kriging cross-
validation, grid cell kriging.
Contents
Certificate
Declaration
Acknowledgement
Abstract
Contents
List of Figures
List of Tables
1. Introduction ……………………………………………………………....... 1
1.1 Background ……………………………………………………... 1
1.2 Objectives ………………………………………………………. 1
2. Methodology Adopted ……………………………………………………… 4
3. Geology of the area ………………………………………………………… 7
3.1 Introduction ……………………………………………………..... 7
3.2 Geology of ISM campus and its Surrounding...………………….. 7
3.3 Physiography and Drainage……………………………………..... 8
3.4 Geomorphology…………………………………………………... 8
3.5 Climate and Rainfall…………………………………………….... 11
3.6 Hydrogeology…………………………………………………...... 12
4. Geophysical Studies………………………………………………………….. 13
4.1 Introduction………………………………………………………. 13
4.2 Geophysical studies………………………………………………. 13
5. Rooftop Rainwater Harvesting and Artificial Recharge………………….. 22
5.1 Rainwater Harvesting.…………………………………………….. 22
5.2 Artificial Recharge……………………………...………………… 23
5.3 Need for Augmentation of Groundwater Resources in ISM……… 26
6. Ground Water Data Organization and Statistical Analysis………………. 28
6.1 Data organization…………………………………………………. 28
6.2 Statistical Analysis……………………………………………....... 28
6.3 Discussion………………………………………………………… 32
7. Geostatistical Modelling of Groundwater Resource……………………… 33
7.1 Introduction……………………………………………………… 33
7.2 Semi-variography………………………………………………... 35
7.3 Block Grids Delineation………………………………………… 39
7.4 Ordinary Kriging………………………………………………… 40
7.5 Results and Discussion……………………………………...…… 47
8. Groundwater Resource Assessment ………………………………………. 54
8.1 Estimates of current Ground water Supply in ISM……………… 54
8.2 Groundwater Resource Estimation Methodology……………….. 56
8.3 Groundwater Recharge…………………………………………... 57
8.3.1 Monsoon Season…………………...……………………... 57
8.3.2 Non-Monsoon Season………………………...…………... 58
8.3.3 Norms for Estimation of Recharge…………….................. 59
8.4 Groundwater Draft………………………………………………. 60
9. Ground Water Quality……………………………………………………... 61
9.1 Chemical analysis of groundwater………………………………. 61
9.2 Hydro Chemical Findings in ISM campus………………………. 61
10. Groundwater Management………………………………………………… 65
11. Conclusion…………………………………………………………………… 66
References 67
List of Tables
Table: 1 Results of VES Carried out in ISM campus
Table: 2 chart showing the fractures encountered
Table: 3 statistics of groundwater in different periods of the year 2014
Table: 4 Groundwater Table data
Table: 5 Model selected for Kriging for different periods
Table: 6 Final parameters are on the last column in blue colour for Pre-monsoon 2014
Table: 7 Final parameters are on the last column in blue colour for Post-monsoon 2014
Table: 8 Final parameters are on the last column in blue colour for fluctuation of Pre and Post
2014
Table: 9 pumping of groundwater in ISM
Table: 10 Units consumed for drafting groundwater in ISM
Table: 11 Location wise groundwater quality in ISM
Table: 12 Groundwater quality in ISM.
List of Figures
Fig: 1 Location of Recharge Pits
Fig: 2 Lines showing the ridge
Fig: 3 Elevation contour map of ISM campus
Fig: 4 Rainfall graph from year 2001 to 2014
Fig: 5 Geophysical VES survey locations
Fig: 8 Geo-electrical Cross Section along West-east direction in ISM campus
Fig: 9 Geo-electrical Cross Section along SW-NE direction in ISM campus
Fig: 10 showing the fractures at different depth
Fig: 11 Resistivity map of ISM, Verma and Rao, 1982
Fig: 12 Different types of artificial recharge techniques
Fig: 13 Recharge pit Section
Fig: 14 Design of Recharge Pit in ISM.
Fig: 15 Dimensions of the recharge pit in ISM
Fig: 16 Satellite view of ISM Dhanbad
Fig: 17 Graph of distribution of Pre-monsoon Groundwater Table
Fig: 18 Graph of distribution of Monsoon Groundwater Table
Fig: 19 Graph of distribution of Post-monsoon Groundwater Table
Fig: 20 Graph of distribution of Fluctuation Groundwater
Fig: 20a Graph showing the pre-monsoon and post –monsoon groundwater level
Fig: 20b Graph showing the Fluctuation level
Fig: 21 Experimental semi-variogram with fitted model for Pre-Monsoon period
Fig: 22 Experimental semi-variogram with fitted model for Post-Monsoon period
Fig: 23 Experimental semi-variogram with fitted model for Fluctuation
Fig: 24 Kriged Estimate distribution map of Pre-monsoon groundwater level
Fig: 25 Kriged Estimate distribution map of Post-monsoon groundwater level
Fig: 26 Kriged Estimate distribution map Fluctuation groundwater level
Fig: 27 Kriged SD map of Pre-monsoon Groundwater Table
Fig: 28 Kriged SD map of Post-monsoon Groundwater Table
Fig: 29 Kriged SD map of Fluctuation Groundwater Table
Fig: 30 Kriged estimate contour map of Pre-monsoon groundwater table
Fig: 31 Kriged estimate contour map of Post-monsoon groundwater table
Fig: 32 Kriged estimate contour map of Fluctuation in groundwater table
Fig: 33 Kriged SD contour map of Pre-monsoon groundwater table
Fig: 34 Kriged SD contour map of Post-monsoon groundwater table
Fig: 35 Kriged SD contour map of Fluctuation in groundwater table
Fig: 36 Kriged Estimate Versus original value for R graph of Pre-monsoon
Fig: 37 Kriged Estimate Versus original value for R graph of Post-monsoon
Fig: 38 Kriged Estimate Versus original value for R graph of Fluctuation
1
Chapter 1
1. Introduction
1.1 Background
The ambitious expansion plan of Indian School of Mines (ISM), Dhanbad with its ongoing
development works have a pressing need of increased groundwater supply within the campus.
With the increase in student strengths, faculty and staff members, additional constructions of
hostels and residential complexes, lecture halls, and expansion of various departments going on in
full swing have increased consumption of groundwater to many folds within a short span of time.
Presently, supply of water is only through overhead storage tanks that are filled with water pumped
from the subsurface using submersible pumps. This has put a great stress in the local aquifer
system. In addition to that, natural areas of infiltration of rain water leading to natural recharge of
groundwater table are getting reduced heavily due to covering by concrete pavements related to
campus development.
ISM campus is underlain by metamorphic rocks and as such there are no primary openings
in the rocks. Fractures in the form of cracks and joints in the rocks contain secondary openings. In
this context, augmentation of groundwater in the fractured aquifer(s) was thought to be necessary.
It was proposed to be carried out through construction of recharge pits in the campus and feeding
them with rainwater that is collected from roof tops and passing on to the subsurface fractures
acting as aquifers. In the case of roof top rain water harvesting and artificial recharge, recharging
takes place in monsoon period. Altogether, a total number of 54 recharge pits were proposed to be
constructed in the campus. Figure 1 shows the locations of the recharge pits within the campus.
1.2 Objectives
It has become imperative on the part of water scientists and planners to adopt techniques for
enumerating the available groundwater resources for sustainable development and management
keeping in mind the scarcity of available water resources versus its demand in the near future. The
apparent heterogeneities and complexities present in the hard rock aquifers makes it a challenging
research to tackle groundwater problems. The intricacy increases manifold for the management of
groundwater when the hard rock aquifers are situated in arid or semiarid Regions.
3
The demand supply gap has led to the over abstraction of the groundwater and water level
depletion in many areas beyond economic exploitation. The Indo-French Centre for Groundwater
Research (IFCGR) at Hyderabad, India has taken this challenge and using a suitable pilot site with
all the fundamentals for studying hard rock aquifers present, has surveyed and experimented
comprehensively a typical/representative granitic aquifer present in a semiarid and monsoon
climate agricultural area.
The present research contains the results and findings of the study carried out in the area
with a thorough investigation of aquifer in hard rock formation. Various works organized in the
thesis extend from understanding of hydrogeology of the area, subsurface fracture aquifers,
geostatistical modelling of the ground water to water resource management. The study also
includes geological, geophysical and remote sensing combination to conceptualize the
hydrodynamics of the area. The basics of the hydraulic tests, conducting various types of hydraulic
tests for parameter estimation in aquifers including their upscaling with modern interpretation
techniques are embedded. A chapter has been included describing the water budgeting and balance
in hard rock aquifers using the specific methods for their estimation in reference to ISM. A major
part of the thesis deals with geostatistical modelling study and aquifer characterisation. This thesis
also covers suitable examples to investigate a hard rock aquifer for characterization of its flow
properties, estimating water balance and finally aquifer modelling for groundwater resource
management using the theory of regionalized variables. Various objectives of the study include:
Hydrogeological understanding of fractured aquifers;
Geological and geophysical studies;
Geostatistical modelling of groundwater levels;
Spatial estimation of the groundwater table during the Pre-monsoon and Post-monsoon
periods, and that of the Fluctuation
To understand and develop water budgeting and balance in hard rock aquifers using the
specific methods for the estimation in reference to ISM;
Estimation of groundwater balance and groundwater flow;
Analysis of Groundwater quality;
Groundwater resource management.
4
Chapter 2
2. Methodology Adopted
Measurement of Ground water levels were carried out for pre-monsoon, monsoon and post-
monsoon periods of the 2014. Statistical and geostatistical methods were applied suitably for an
understanding of population and spatial characteristics of the aquifer with reference to the
groundwater recharge from rooftop rain water harvesting structures built in the campus of ISM
Dhanbad.
Parameters such as Mean, Standard Deviation, Skewness and Kurtosis have been computed to
gain an understanding of the population characteristics. For an understanding of the spatial
distribution properties, the theory of geostatistics have been applied. Geostatistics theories has
been described by several authors (Goovaerts, 1997; Isaaks & Srivastava, 1989; Kitanidis, 1997).
The major tool of geostatistics is the variogram which expresses the spatial dependence between
neighboring observations. The variogram, Ɣ (h), is defined as one-half the variance of the
difference between the attribute values at all points separated by h as follows where Z(x)
indicates the magnitude of variable, and N (h) is the total number of pairs of attributes that are
separated by a distance h.
Before we do geostatistical estimation, we have need of a model that supports us to
calculate a variogram assessment for any probable sampling interval. The most commonly used
models are spherical, exponential, Gaussian, and pure nugget effect (Isaaks & Srivastava, 1989).
The appropriateness and rationality of the developed variogram model was tested satisfactorily
by a technique called cross-validation. The clue of cross-validation comprises of removing a
datum at a time from the data set and re-estimating this value from left over data using different
variogram models. Interpolated and real values are co-related, and the model that yields the most
precise extrapolations is retained (Goovaerts, 1997; Isaaks & Srivastava, 1989; Leuangthong,
McLennan, & Deutsch, 2004). Crossing plot of the estimate vs the true value shows the
correlation coefficient (R2). The utmost appropriate variogram was selected constructed on the
highest correlation coefficient by trial and error technique.
5
Kriging is a meticulous interpolation estimator technique used to find the finest linear
unbiased estimate. The best linear unbiased estimator essentially should have minimum variance
of estimation error. Among the different kriging methods, we used ordinary and universal kriging
for spatial and temporal analysis, respectively. Ordinary and universal kriging methods are mainly
applied for datasets without and with a trend, correspondingly. Detailed deliberations of Kriging
methods and their metaphors can be found in Goovaerts (1997). The universal equation of linear
kriging estimator is:
In order to attain unbiased estimations of ordinary Kriging the following set of equations
have to be solved concurrently.
where Z * (xp) is the kriged value at position xp, Z * (xi) is the known value at location xi, λi is
the weight associated with the data, μ is the Lagrange multiplier, and γ (xi, xj) is the value of
variogram corresponding to a vector with derivation in xi and extremity in xj.
The general equations of unbiased universal kriging which must be solved concurrently are as
follows.
Where f (x) is the type of function used to model the trend and is directly suggested by the
physics of the problem (Goovaerts, 1997). The gexsys software developed by Dr B.C.Sarkar was
used for geostatistical analysis in this study. The monthly groundwater level (depth to water table)
of 54 Bore wells were monitored persistently from 2014 of which from May-2014 data are used.
These bore wells are distributed across the ISM campus to represent the fluctuations of
groundwater level of the whole area of plain. Recorded data for each bore well consists of monthly
groundwater table were measured for all bore wells for the year 2014. Here some values are
6
omitted as being considered completely erroneous values. Though, there exist some outliers or
extreme values which are not removed from the data set since according to Goovaerts (1997) in
environmental applications large values may indicate potentially critical points so they should be
removed only if they are clearly wrong.
7
Chapter 3
3. Geology of the area
3.1 Introduction
Indian School of Mines (ISM) campus is bounded between 23049’16” N, 86026’06” E and
23048’36” N, 86026’55” E with an average elevation of 247.314m above mean sea level and is
included in Survey of India Topographic map number 73I/5. ISM is well connected by road and
rail. A detailed geo-electric survey in the campus of Indian School of Mines, Dhanbad has
previously been carried out to locate suitable sites for tube wells (Verma, 1982). As part of the
survey, the entire area was covered by Schlumberger soundings as well as Wenner
profiles. The weathered metamorphic layer whose resistivity contrasts from 3 0 to 80 ohm-m
was found to be the main aquifer. The width of the weathered layer is quite inconsistent,
vacillating from 8 to 45 m. At places, semi-weathered/fractured rocks underlie the weathered
layer and provide good aquifer environment. The apparent resistivity map prepared on the basis
of detailed profiling demarcates low resistivity zones that are favorable for groundwater
storage.
3.2 Geology of ISM campus and its surrounding
The geology of ISM Campus is a part of the geology of Dhanbad urban area. The area is a
part of Chotanagpur Gneissic Complex and is characterized by a diverse assemblage of igneous
and metamorphic rocks. In general the succession of the various rock groups are as follows:
Soils and recent sediments
Coal Bearing Gondwana Group of rocks
Gabbro, dolerite (Intrusions)
Pegmatite, and leucogranite (intrusions)
Megacryst porphyritic granite (intrusions)
Quartzo-feldspathic gneisses with mafic enclaves (Basement) equivalent to Chotanagpur
Gneissic complex
The outcrops of these rocks are variably found scattered around ISM within 7-8 km radius.
The Chotanagpur gneissic complex is an assemblage of quartzo-feldspathic gneisses with augen
8
structure that are coarse to very coarse and occasionally inter-banded with mafic bands and lenses.
These are metamorphosed to medium grade. These rocks are well exposed in the Khudia Nala
section north of Govindpur and also along the railway cutting sections near Pradhankhanta. These
are deformed into early reclined fold that are refolded into WSW-ENE trending upright sub-
vertical folds.
All rocks described above are traversed by fractures, joints and faults of different scales. The
schistosity and gneissosity of granites and basement gneisses respectively favours the directional
passages of ground water. Faults, joints are also important for infiltration and circulation.
3.3 Physiography and Drainage
The Dhanbad town is situated in Chotanagpur Plateau. Hence the physiographic feature
will be similar to a plateau area. But there are lot of local topographic variation in this plateau
within the campus since there are one or two E-W running ridges. The main heritage building,
Diamond hostel, Penman Auditorium, Opal Hostel, Lower ground and Upper ground are situated
on a flat but elevated ground with respect to others. If we go towards east i.e. towards Teachers
Colony the topographic elevation initially goes down up to the new generator house. If one moves
further east, i.e. towards Teachers’ Colony, the topographic elevation again rises. This fall and rise
of topography is separated from each other by a nala which flows in a northerly direction. Another
northerly flowing nala occurs further east i.e. about 50m east of Ruby hostel.
To the west of main Heritage building, again there is a fall in the topographic elevation (area
around Tennis Ground). The Emerald, Topaz and Sapphire hostel are situated opposite to this
depressed ground are at a relatively higher topography.
3.4 Geomorphology
Existence of plateau type topography which covers a major part of the ISM campus indicates
that a long phase of denudation and peneplanation. Occurrence of linear ridges has resulted into a
local uneven landscape. Humid tropical climate, jointed and fractured basement rocks may be the
main controlling factors for weathering. Humid tropical climate might have led to the formation
of thick weathered basement and whitish red colour soil formation.
11
3.5 Climate and Rainfall
The area falls under sub-tropical humid climate zone. The average temperature ranges from
20.010C to 44.460C. Heavy rainfall starts from the months of June (1403.9 mm). This continues
up to October (679.2 mm). Highest rainfall occurs in the months of July (2798.2 mm). Rainfall
during September is 2085.3mm and almost nil to scanty during November and December. Total
rainfall during January to May is much less than June to October, but higher than November and
December. This observation has been substantiated in Fig: 4 shows the plot of total rain fall (in
mm) from 2001 to 2014. This shows that there is a large fluctuation in rain fall from 2001 to 2014.
The highest rainfall (1447.8mm) was in 2001 and lowest during 2004 to 2006. Though there is
again a rise in the rainfall since 2007, an overall decreasing trend is very conspicuous. Such a
situation is very alarming for the future groundwater potential of the ISM campus as its population
is increasing substantially and our domestic need is only met from groundwater of this campus.
Hence the artificial recharge is very essential to generate future generation.
Fig: 4 Rainfall graph from year 2001 to 2014
y = -8.36x + 331.44
R² = 0.0839
0.00
100.00
200.00
300.00
400.00
500.00
600.00
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014
RAINFALL MONTHLY(mm) AND ITS TRENDJan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
R=0.289
Decreasing
Trend of
Rainfall
12
3.6 Hydrogeology
The campus of ISM is green and is well vegetated inside. In general the ground surface
within ISM campus does not show much of outcrops of rocks except for some outcrops of
metamorphic rocks in the North western part of the campus. Igneous rocks occur beneath a thin
veneer of soil cover as intrusive body. Since there are no sedimentary formations beneath ISM,
there is no primary aquifer in a true sense. The secondary openings in the metamorphic rocks in
the form of joints, fractures, and faults in the hard rocks act as a media for ground water circulations
and act as aquifer. During rainy seasons these secondary openings get recharged through
infiltration from open grounds. In recent years, the per-capita consumption of groundwater has
increased many folds due to increase in intake of students and multifaceted expansion programs
that include construction of new buildings, hostels, residential complexes, beautification of the
campus etc. Through such activities the open area available for infiltration has decreased
substantially. Increased use and decreased infiltration have produced additional stress in the
present aquifer leading to decline of water levels in dug wells as well as bore wells in the close
vicinity of the pumping bore wells. In this hydro-geological situation, there is an urgent need of
artificial recharge to rejuvenate groundwater domain.
13
Chapter 4
4. Geophysical studies
4.1 Introduction
In continuation to the artificial recharge structure constructed in ISM Dhanbad for the
purpose of increasing the groundwater table in the area a detail geophysical survey was carried out
By CGWB, Patna to study the sub surface geological setting.
This survey comprises of Vertical Electrical Sounding (VES) to study the sub surface
conditions such as; the extent of weathering, fracture pattern and depth to basement.
This study concludes the details of the investigation and geophysical conclusions.
4.2 Geophysical Studies
Geophysical studies were carried out jointly with CGWB. In this, the electrical resistivity
method was used to investigate the subsurface geology by studying the variations in the electrical
properties, this is one of the most common method employed in the study of ground water bearing
zones, to identify the lithology, depth and the thickness of the detectable layer. The ‘Vertical
Electrical Sounding’ (VES) are used to estimate the vertical variations in electrical resistivity. The
VES curves were interpreted both manually and by using software and the results are given in the
Table1 and VES Curves are shown in Fig 6 and 7.
Based on VES results, cross sections were prepared along West-East and SW-NE directions. The
geoelectical sections are given in Fig 8 and 9. The cross section West-east shows that the top soil
thickness is uniform ranging from 0.75-2.4m followed by highly weathered layer. The weathered
layer has uniform thickness of 2.2 to11.0m except in the eastern part where the thickness is 11m.
This zone is underlain by semi-weathered/ fractured formation which is less in the western part
and more in eastern part with a thickness range of 4.7 to36.1m. It was also noticed that it is more
prominent near Sapphire and near Lower Ground. Again this zone is followed by highly weathered
layer but this layer is missing at Student Activity Centre (SAC) and Lower Ground and the
thickness range is between 10.0to21.5m. This zone is underlain by massive rock.
The cross Section SW-NE shows that the top soil thickness is uniform ranging from 0.75
to 1.1m followed by weathered layer which is missing at Staff Quarters and in the Lower Ground
the thickness ranges between 2.2 to3.4m. This layer is again followed by highly weathered layer
14
which is uniform except near Teachers Colony where it is missing and the thickness range of this
is 8.9 to 16.3m. This zone is again underlain by semi-weathered or fractured formation which is
prominent in the NE part and is missing at Old Health Centre and the thickness range of this layer
is from 15.0 to 37.7m. This geophysical study concluded that the area is underlain by crystalline
metamorphic rocks of Archean age which forms the basement rock and enclaves of older
metamorphic rocks. The Groundwater is occurring in the phreatic conditions in the weathered zone
and under semi-confined conditions in the deep seated fractures of the rocks.
18
Fig: 8 Geo-electrical Cross Section along West-east direction in ISM campus
Fig: 9 Geo-electrical Cross Section along SW-NE direction in ISM campus
19
Sr.
No.
Location Date Latitude (y) Longitude (x) Depth
drilled
(mbgl)
Casing
length
(m)
Logged
Depth
(mbgl)
Fracture
encountered
(mbgl)
Remark
1 Sapphire
Hostel
08.3.2014 86°26'11.3'' 23°49'09.7'' 72 9.44 69 unable to
interpret the
logging
data
2 Student
Activity
Centre
08.3.2014 23°49'01.2'' 86°26'16.2'' 74 11.59 70 24 - 26.8,
41.6 - 44,
58.4 - 60.4
3 Topaz
Hostel
09.3.2014 23⁰49'06.2'' 86⁰26'16.3'' 55 9.4 53 14.6 - 16.6 at 23.4
mbgl
formation
change
4 Amber
Hostel
09.3.2014 23°49'06.5'' 86°26'23.2'' 55 15.21 53 19.4 - 20.6,
26.6 - 29.8,
32.2 - 34.2,
43.4 - 48.2
5 New
Lecture
Complex-2
09.3.2014 23°49'00.3'' 86°26'21.3'' 72 18 54 33.6 - 35,
37.2 - 41.6
6 Jasper
Hostel
09.3.2014 23°49'03.3'' 86°26'27.6'' 72 16.15 68 36 - 42.8,
48.8 - 50.8,
54.8 - 57.2,
59.6 - 63.2
upto 29.6 m
bgl
weathered
rock
20
7 Staff
Quarters-2
(Behind
Dhurga
Mandir)
09.3.2014 23°48'43.1'' 86°26'15.1'' 72 15.25 70 19.6 - 21.2,
24.8 - 29.6,
30.8 - 32.4,
44 - 46.8
8 Diamond
Hostel
09.3.2014 23°48'55.9'' 86°26'27.4'' 72 15.24 35 upto 34 m
bgl highly
fracture
zone
9 SBI,
Govindpur
10.3.2014 70 19.8 66 32 - 36,
39.2 - 40.8
10 Shanti
Bhawan
10.3.2014 24°48'52.4'' 86°26'39.5'' 55.3 15.24 39 19 - 22.2,
34.6 - 36.4
Table: 2 Location showing the fractures encountered
Fig: 10 VES logs showing fractures at different depth
21
After the Geophysical studies, the selection of suitable site for recharge in ISM is done based on
the various factors;
• Availability of space for construction of recharge structures.
While preparing the recharge scheme, depth and shape of the storage facility in recharge structure
depends on:
-Availability of runoff
-Space availability in an area
It was observed by the ISM team that the recharge pits would be 10x30x10 (ft.) and is located in
open area that is distant from sewage structure and services. Previous studies done by Prof. R.K.
Verma and C.V. Rao in 1982 also shows that there is a fracture zone in the section A-A’ which is
plotted on graph. In his study he found that the weathered metamorphic layer whose resistivity
varies from 30to 80 ohm-m is found to be main aquifer. The thickness of the weathered layer is
about 8 to 45 meters. At some places semi weathered/fractured rocks under lie the weathered layer
and provide good aquifer conditions.
Fig: 11 Resistivity map of ISM, Verma and Rao, 1982
22
Chapter 5
5. Roof top Rain water Harvesting and Artificial Recharge
5.1 Rainwater harvesting
Rainwater harvesting is the techniques of collection and storing of rainwater for reuse
rainwater on-site, rather than allowing it to runoff. It is a process of arresting runoff water from
the roof tops and are let of into the outlets that are connected through a pipe to a storage tanks and
let into gravel filled trenches, pits to serve as recharge conduits. The uses of this recharge water
include gardening, livestock, irrigation and domestic use with proper treatment. Rainwater
harvesting systems can be installed with minimal skills. The system should be sized to meet the
water demand throughout the dry season since it must be big enough to support daily water
consumption. Specifically, the rainfall capturing area such as a building roof must be large enough
to maintain adequate flow. The water storage tank size should be large enough to contain the
captured water. Historically, this method is very old .In ancient Tamil Nadu (India), rainwater
harvesting was done by Chola Kings. Rainwater from the Brihadeeswarar temple was collected in
Shivaganga tank. During the later Chola period, the Viranam tank was built (1011 to 1037 CE) in
Cuddalore district of Tamil Nadu to store water for drinking and irrigation purposes. Viranam is a
16-kilometre (9.9 mi) long tank with a storage capacity of 1,465,000,000 cubic feet
(41,500,000 m3). Rainwater harvesting was done in the Indian states of Madhya
Pradesh, Maharashtra, and Chhattisgarh in the olden days. Ratanpur, in the state of Chhattisgarh,
had around 150 ponds. Most of the tanks or ponds were utilized in agriculture works. Recently in
Tamil Nadu, rainwater harvesting was made compulsory for every building to avoid ground water
depletion. It proved excellent results within five years, and every state took it as role model. Since
its implementation, Chennai saw a 50 per cent rise in water level in five years and the water quality
significantly improved. In Rajasthan, rainwater harvesting has traditionally been practiced by the
people of the Thar Desert. There are many ancient water harvesting systems in Rajasthan, which
have now been revived. Water harvesting systems are widely used in other areas of Rajasthan as
well, for example the chauka system from the Jaipur district. At present, in Pune (Maharashtra),
rainwater harvesting is compulsory for any new society to be registered. An attempt has been made
at Dept. of Chemical Engineering, IISc, Bengaluru to harvest rainwater using upper surface of a
solar still, which was used for water distillation.
23
In the context of ISM the Need for rainwater harvesting is because the surface water and other
water supply systems are slowly becoming inadequate to meet the demand here and have to depend
on ground water. This is happening due to rapid growth of the population in ISM also infiltration
of rain water into the sub-soil has decreased drastically and recharging of ground water has
diminished. So, to enhance the availability of ground water at ISM campus it became necessary to
raise the water level in wells and bore wells that are drying up. Also it helps in reduction of power
consumption and will improve the water quality in aquifers. Here, in ISM rain water is being
collected on the roofs of the building and from there it is being transported to the recharge pits
nearby which are constructed there.
5.2 Artificial Recharge:
Groundwater recharge or deep drainage or deep percolation is hydrologic process
where water moves downward from surface water to underground. This process usually occurs in
the vadose zone below plant roots and is often expressed as a Flux to the groundwater table surface.
Recharge occurs both naturally (through the water cycle) and through anthropogenic processes
(i.e., "artificial groundwater recharge"), where rainwater and /or reclaimed water is routed to the
subsurface. Artificial groundwater recharge is becoming increasingly in India. More pumping of
groundwater by farmers has led to underground resources becoming depleted. In 2007, on the
recommendations of the International Water Management Institute, the Indian government
allocated Rs.1800 crore (US$400million) of funds to dug-well recharge projects (a dug-well is a
wide, shallow well, often lined with concrete) in 100 districts within seven states where water
stored in hard-rock aquifers had been over-exploited.
Groundwater is recharged naturally by rain and snow melt and to a smaller extent by surface water
(rivers and lakes). Recharge may be impeded somewhat by human activities including paving,
development, or logging. These activities can result in loss of topsoil resulting in reduced water
infiltration, enhanced surface runoff and reduction in recharge. The volume-rate of abstract from
an aquifer in the long term should be less than or equal to the volume-rate that is recharged.
Recharge can help move excess salts that accumulate in the root zone to deeper soil layers,
or into the groundwater system. Tree roots increase the water saturation and reducing the
water runoff. Flooding temporarily increases river bed permeability by moving clay soils
downstream, and this increases aquifer recharge.
24
There are various artificial recharge techniques; flow chart shows the different types of it and the
marked one is the technique used in ISM.
Fig: 12 Different types of artificial recharge techniques
26
Fig: 15 Dimensions of the recharge pit in ISM
5.3 Need for Augmentation of Groundwater Resources in I.S.M.
Augmentation of Ground water became very crucial in ISM because there was a sudden
increase of human population in the campus and there was high demand water expected due to
increase in new developmental works carried out in the campus. Also it became necessary to
efficiently manage the available resources as to meet the growing needs and demands adequately.
This conservation and augmentation has to follow appropriate means and also the effective route.
It was planned to be done by conservation and storage of surplus surface water run-off in
groundwater or sub-surface reservoirs in ISM campus and enhance the sustainable yield in the
ISM.
Other important reasons for need of artificial recharge were:
• Increased numbers of building in the campus due to development requirements.
• Improve the quality of existing groundwater through dilution.
• Save energy for lifting of groundwater from depleted level
• Decreasing area of open space or grass land which resulted in less water recharge and
increased the surface run off.
• Excessive ground water withdrawal.
27
• Decrease in infiltration due to decrease in open space area.
Fig. 16 shows the satellite view of the ISM campus and the rate of depletion of open grass land
which is affecting the water table.
Fig: 16 Satellite view of ISM, Dhanbad
28
Chapter 6
6. Ground Water Data Organization and Statistical Analysis
6.1 Data organization
Collection and collation of ground water data is a very important exercise and needs very
careful observation. The study covers a total area of 218 acres within the campus of Indian School
of Mines (ISM) situated in the Dhanbad, in the state of Jharkhand. There is a very high demand of
water as discussed in the previous chapters. To meet this demand, a project on “Rain Water
Harvesting and Artificial Recharge” proposed by ISM was sanctioned in August-2011 under
Central Sector Scheme “Ground Water Management and Regulation” in The State of Jharkhand
during XIth plan by the Central Ground Water Board (CGWB), Ministry of Water Resources for
implementation in the ISM campus. The project included construction of 54 recharge pits with
recharge bores along with connecting down pipes from rooftops and horizontal pipes to the
recharge pits. The constructions were to recharge the fractured aquifer system of the campus area.
The recharge pits of the dimension of 10ft x 3ft x 3ft are suitably placed at different locations
inside the campus with recharge bores, depth of which varies from 55m to 72 m and diameter of 4
inch. The recharge pits were located in an open areas near to buildings with roof top catchment
and are distant from sewage structures and services. Ground water level data were recorded from
the recharge bores in every month with the help of water level sounder. In this study, the
groundwater levels of pre-monsoon, monsoon and post-monsoon and fluctuation of pre-monsoon
and post-monsoon water levels were organized in a database, which were then analysed for
statistical and geostatistical study.
6.2 Statistical Analysis
Statistical Analysis of Groundwater table for Pre-monsoon, Monsoon, Post-monsoon and
Fluctuation for the year 2014 is shown in the table below.
29
Sr.
No.
Period Mean Range SD Skewness Kurtosis
Min Max
1. Pre-Monsoon(May-June) 240.652 225.874 246.140 3.922 -1.609 6.262
2. Monsoon(July-Aug-Sep) 242.124 227.804 246.865 3.870 -1.690 6.360
3. Post-Monsoon(Oct-Nov-Dec) 242.192 231.664 247.497 3.251 -1.068 4.678
4. Fluctuation Between Pre-
monsoon and Post-monsoon
1.862 0.045 8.715 1.407 2.703 13.228
Table: 3 statistics of groundwater in different periods of the year 2014
0
5
10
15
20
25
30
Fre
quen
cy
Class Interval
Fig: 17
Pre-Monsoon 2014
0
2
4
6
8
10
12
14
Fre
qu
ency
Class Interval
Fig:18
Monsoon 2014
0
5
10
15
20
25
Fre
quen
cy
Class Interval
Fig: 19
Post-monsoon 2014
0
5
1015
20
25
3035
Fre
quen
cy
Class Interval
Fig: 20
Fluctuation 2014
30
Fig: 20a Graph showing the pre-monsoon and post –monsoon groundwater level
215.0000
220.0000
225.0000
230.0000
235.0000
240.0000
245.0000
250.0000
Sap
hir
e H
ost
el
Sap
hir
e H
ost
el
Sap
hir
e H
ost
el
Sap
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ost
el
Sap
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ost
el
Sap
hir
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ost
el
Top
az H
ost
el
Top
az H
ost
el
Stu
de
nt
Act
ivit
y C
entr
e
Stu
de
nt
Act
ivit
y C
entr
e
Stu
de
nt
Act
ivit
y C
entr
e
Am
ber
Ho
stel
Am
ber
Ho
stel
Am
ber
Ho
stel
Am
ber
Ho
stel
Bac
k Si
de
of
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ald
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ste
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it
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de
of
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ald
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ste
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it
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nt
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eral
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ost
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eral
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it
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ost
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Her
itag
e B
uild
ing
Dia
mo
nd
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ste
l
Op
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ost
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Op
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ost
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Op
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ost
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Op
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ost
el
Old
Lib
rary
Pet
role
um Sh
anti
Bh
awan
Haw
a M
ahal
Haw
a M
ahal
Wo
rk s
ho
p &
MM
E
Sta
ff C
olo
ny
Typ
e II
,
Sta
ff C
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ny
Typ
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,
Low
er g
rou
nd
Lect
ure
hal
l co
mp
lex
II
Lect
ure
hal
l co
mp
lex
II
Hea
lth
Cen
tre
(old
)
Teac
her
s co
lon
y
Teac
her
s co
lon
y
SBI B
ank
ISM
SBI B
ank
ISM
Gro
und w
ater
tab
le D
epth
Location
Groundwater Table in Pre and Post- monsoon 2014
Pre-monsoon 2014 Post-monsoon 2014
31
Fig: 20b Graph showing the pre-monsoon and post –monsoon groundwater
0
1
2
3
4
5
6
7
8
9
10
Sap
hir
e H
ost
el
Sap
hir
e H
ost
el
Sap
hir
e H
ost
el
Sap
hir
e H
ost
el
Sap
hir
e H
ost
el
Sap
hir
e H
ost
el
Top
az H
ost
el
Top
az H
ost
el
Stu
de
nt
Act
ivit
y C
entr
e
Stu
de
nt
Act
ivit
y C
entr
e
Stu
de
nt
Act
ivit
y C
entr
e
Am
ber
Ho
stel
Am
ber
Ho
stel
Am
ber
Ho
stel
Am
ber
Ho
stel
Bac
k Si
de
of
Emer
ald
Ho
ste
l p
it
Bac
k Si
de
of
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ald
Ho
ste
l p
it
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nt
Sid
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eral
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ost
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eral
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Her
itag
e B
uild
ing
Dia
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nd
Ho
ste
l
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ost
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ost
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Op
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ost
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Old
Lib
rary
Pet
role
um Sh
anti
Bh
awan
Haw
a M
ahal
Haw
a M
ahal
Wo
rk s
ho
p &
MM
E
Sta
ff C
olo
ny
Typ
e II
,
Sta
ff C
olo
ny
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e II
,
Low
er g
rou
nd
Lect
ure
hal
l co
mp
lex
II
Lect
ure
hal
l co
mp
lex
II
Hea
lth
Cen
tre
(old
)
Teac
her
s co
lon
y
Teac
her
s co
lon
y
SBI B
ank
ISM
SBI B
ank
ISM
Flu
ctu
atio
n in
Met
er
Location
Fluctuation 2014
32
6.3 Discussion
The minimum and maximum values for pre-monsoon has a mean of 240.652 and standard
deviation (SD) of 3.922 giving a co-efficient of variation (SD/mean) 61.35 which is very high. The
skewenss value is -1.609, it is very high and negatively skewed (Fig 17). Kurtosis value is 6.262
and is in the range of lepto-kurtic since it is more than 3and thus it is non-normal distribution. The
Table-3 gives the statistical values for all pre-monsoon, monsoon, post-monsoon and fluctuation
which are different for all but the character of the three periods are all same leaving the fluctuation.
The parameters showed that the value range is beyond 7 confirming it to be log-normal
distribution. The figure17-19 showing the log-normal distribution of groundwater.
33
Chapter 7
7. Geostatistical Modelling of Ground Water Resource
7.1 Introduction
In this part Geostatistical modelling is carried out with semivariography i.e.
characterization of spatial distribution of groundwater. A semivariogram model exhibit various
characteristics that display spatial distribution parameters i.e. Nugget effect (C0), Continuity (C),
range of influence (a) and anisotropy. To investigate the seasonal variation in both the season i.e.
pre-monsoon and post-monsoon and to model the fluctuation of ground water table in and around
ISM Dhanbad, geostatistical method is used. The methods adopted is to study the spatial
distribution of groundwater table in the ISM campus and to generate the ground water distribution
maps. Since the area is a hard rock terrain the major aquifer system is in fractured zones and the
basement rock with shallow fractures generally encountered at various depths ranging from 10 to
70 meters. There are different fractured zones and each zone has different thickness. Groundwater
level data were collected in 48 wells during pre-monsoon, in 34 wells during monsoon and in 54
wells during post-monsoon periods in the year 2014. The data were collected manually and then
processed for statistical and geostatistical analysis. The entire one year data of 2014 were divided
in to pre-monsoon, monsoon and post-monsoon in which the pre-monsoon consists of the average
water table of May-June, monsoon consists of average water table of July-August-September and
Post-monsoon consists of the average water table of October-November-December. For the study
of fluctuation, the difference of water table depth of pre-monsoon and post-monsoon was
calculated which is given in Table 4.
Location Name
Pre-
monsoon
Post-
monsoon Fluctuation
Sapphire Hostel 243.6189 244.0339 0.4150
Sapphire Hostel 242.8900 243.8900 1.0000
Sapphire Hostel 243.7339 244.5089 0.7750
Sapphire Hostel 242.3889 243.2989 0.9100
Sapphire Hostel 242.2067 242.9667 0.7600
Sapphire Hostel 246.1406 246.5906 0.4500
34
Topaz Hostel 242.0103 242.8253 0.8150
Topaz Hostel 243.7641 244.2791 0.5150
Student Activity Centre 241.4003 242.4453 1.0450
Student Activity Centre 240.7636 242.4636 1.7000
Student Activity Centre 239.2210 242.3860 3.1650
Amber Hostel 243.8109 245.4259 1.6150
Amber Hostel 243.6751 245.6701 1.9950
Amber Hostel 243.8572 245.2472 1.3900
Amber Hostel 238.3111 239.5161 1.2050
Back Side of Emerald Hostel 243.8713 245.4163 1.5450
Back Side of Emerald Hostel 243.8230 245.3680 1.5450
Front Side of Emerald Hostel 244.9946 246.5146 1.5200
Front Side of Emerald Hostel 244.2362 245.2062 0.9700
Jasper Hostel 237.6016 237.9966 0.3950
Jasper Hostel 239.3737 240.8937 1.5200
Jasper Hostel 242.4050 244.3250 1.9200
Heritage Building 240.7042 242.2392 1.5350
Diamond Hostel 243.1233 244.7933 1.6700
Opal Hostel 241.0454 244.2804 3.2350
Opal Hostel 245.2572 247.4972 2.2400
Opal Hostel 240.8138 243.7738 2.9600
Opal Hostel 241.5937 243.9087 2.3150
Old Library 239.2508 241.7908 2.5400
Petroleum 229.3721 231.8121 2.4400
Shanti Bhawan 236.3884 238.7684 2.3800
Hawa Mahal 236.6502 238.8152 2.1650
Hawa Mahal 236.4069 238.9369 2.5300
Work shop & MME 241.8070 241.8520 0.0450
35
Staff Colony Type II, 236.9900 239.4000 2.4100
Staff Colony Type II, 236.9903 238.2853 1.2950
Lower ground 238.1001 240.0951 1.9950
Lecture hall complex II 241.8707 243.1557 1.2850
Lecture hall complex II 239.7728 242.1878 2.4150
Health Centre (old) 238.2449 240.4249 2.1800
Teachers colony 225.8745 231.6645 5.7900
Teachers colony 233.4261 242.1411 8.7150
SBI Bank ISM 244.7678 246.7928 2.0250
SBI Bank ISM 241.4679 244.0429 2.5750
Table: 4 Groundwater Table data
7.2 Semi-variography
Point kriging
Point kriging is a method of estimation or interpolation of a point by a set of neighbouring
sample points applying the theory of regionlized variables where the sum of weight coefficients
sum to unity and produce a minimum variance of error.
Expressed mathematically, kriged estimate is given as-
P*=∑aisi
Where P*= the estimate of true value sat a point ‘p’
ai= weight coefficient of the individual samples
si= individual sample values at sample points, si.
And kriging variance is given by
𝝈k2=∑ ai𝜸(si,p)+ λ
Where, λ= Lagrangian multiplier and 𝛾(si, p) = average semi-variance among samples and the
point to be estimate.
36
According to David (1977) point kriging is a procedure for checking the validity of a
semivariogram model that represents the underlined semivariograms. A spherical model is fitted
to an experimental semivariogram by adjusting C0 (Nugget effect), C (Continuity) and a (range).
To understand the anisotropy of the fluctuations and level of groundwater table during pre and
post monsoon, comparison of variograms with experimental semivariograms to cross validate
with the model was done. During this procedure, since the sample points are randomly distributed,
different lag distance and sample interval was taken to fit the spherical model ( Fig: 21,22,23 )
These models were Cross validated with Point Kriging Cross Validation Technique and were fitted
to the experimental semi-variogram models. The Point kriging cross validation was done by
selecting the most suitable range, nugget, continuity and keeping the sill value at the most suitable
place so that maximum points can be covered and best fit can be obtained
Cross-validated models as obtained employing Point kriging cross-validation technique for
Pre-monsoon, Post-monsoon, and Fluctuation given in Figure 21, 22, and 23 and the analysis of
the point kriging cross validation are given in Table 6, 7 and 8 respectively.
0 500 1000 1500
0
5
10
15
20
25
30
35
40
C0
+C
Lag (m)
Fig: 21 Experimental semivariogram with fitted model for Pre-Monsoon period
37
0 200 400 600 800 1000 1200
0
10
20C
0+
C
LAG (m)
Fig: 22 Experimental semivariogram with fitted model for Post-Monsoon period
0 200 400 600 800 1000 1200 1400 1600 1800 2000
0
1
2
3
4
5
6
C0
+C
Lag (m)
Fig: 23 Experimental semivariogram with fitted model for Fluctuation
38
Sr. No. Period Model
1. Pre-monsoon γ(h)= 3.0+23[(1.5xh/875)-1.5(h/875)3]
2. Post-monsoon γ(h)= 3.8+10[(1.5xh/600)-1.5(h/600)3]
3. Fluctuation γ(h)= 0.7+1.40[(1.5xh/800)-1.5(h/800)3]
Table: 5 Model selected for Kriging for different periods
Variogram models were cross validated by taking the various lag distances as the sample
distance were randomly distributed and to get the best fitted model the exercise was carried out
Table 6, 7 and 8 gives the details of the exercise and various values for fulfilling the parameters.
Semi
Variogram Parameters
Initial Parameter values Final
Values
C0 2.0 2.6 2.6 2.6 2.7 3.0 4 3.0 3.0
C 19 22 21.6 22 22 22 21 22 23
C0+C 21 24.6 24.6 24.6 24.7 25 25 25 26
Range(a) 900 750 750 800 750 850 800 875 875
KE:EV 1.43 1.07 1.08 1.10 1.04 1.04 0.87 1.05 1.03
Table: 6 Initial and Final parameter values of Point kriging cross validation process for Pre-
monsoon 2014
Semi
Variogram
Parameters
Initial Parameter values Final
Values
C0 3.41 3.40 3.41 3.41 3.41 3.4 3.4 3.4 3.8
C 12.0 12.1 12.0 12.0 12.0 10.5 11.0 10.5 10.0
C0+C 15.41 15.51 15.41 15.41 15.41 13.9 14.4 13.9 13.8
Range(a) 1000 1050 800 700 600 600 800 500 600
KE:EV 1.20 1.22 1.14 1.09 1.05 1.09 1.17 1.05 1.02
Table: 7 Table: 6 Initial and Final parameter values of Point kriging cross validation process for
Post-monsoon 2014
39
Semi
Variogram Parameters
Initial Parameter values Final
Values
C0 0.32 0.50 0.6 0.5 0.55 0.4 0.55 0.6 0.7
C 1.98 1.5 1.4 1.4 1.35 1.65 1.60 1.45 1.40
C0+C 2.3 2 2 1.9 1.9 2.05 2.15 2.05 2.1
Range(a) 800 650 650 650 650 700 670 700 800
KE:EV 1.30 1.08 1.02 1.04 1.08 1.04 1.02 1.04 1.04
Table: 8 Table: 6 Initial and Final parameter values of Point kriging cross validation process for
fluctuation of Pre and Post 2014
It can be observed that in pre monsoon and post monsoon the nugget is 3.0 and 3.8 but in
the fluctuation case the nugget goes to 1.40 which is almost half of the pre and post monsoon.
Therefore, the accuracy of the Kriged values depends on the variogram values at most possible
small lag distances (Isaaks & Srivastava, 1989) and the fig 21. Clearly demonstrates that first few
points associated to lag distance carry more weights of spatial structure (Ma et al., 1999).
7.3 Block Grids Delineation
Kriging
The geostatistical procedure of estimating values of a regionalized variable using the
information obtained from a semi-variogram is kriging. Its application to groundwater hydrology
has been described by number of authors, viz. Delhomme(1976,1978,1979), Delfiner and
Delhomme(1953),Marsily et al. (1984), Marsily (1986),Aboufirassi and Marino(1983,1984),
Gambolti and Volpi (1979) to name a few.
Let G* be the kriged estimate of the average value of grid G of the samples having values g1, g2,
g3……gn. Let a1, a2, a3……an be the weightage giving to each of the values respectively such that
∑ai=1; and G*=∑aigi. Thus the estimation becomes unbiased; the mean error is zero for a large
40
number of estimated values and the estimated variance is minimum. The kriging variance is given
as
𝛔𝐤𝟐 = ∑(𝐠𝐢 − 𝐆∗)2
To make kriging variance minimum, a function called Lagrange multiplier (λ), is used for
optimal solution of the kriging system. Kriging carried out for a point estimate is called point
kriging and that accomplished for making estimates of a block of ground is known as block kriging.
The kriging technique is applied for analytical purpose and is discussed below.
Prior to kriging the block size of the study area was decided by taking into account the
various parameters i.e. area, fluctuation of ground water and the best fitted block which can cover
the maximum extent near to the boundary of the ISM. Since area is small and is heterogeneously
extended from all direction here, 25m x 25m x 25m dimensions of the block size was delineated
after a number of exercises so that kriging can be done for whole area. After the delineation of the
block grid of the dimension 25m x 25m x 25m the center points of each block was taken and the
kriging technique was applied.
7.4 Ordinary Kriging
Here Ordinary Kriging was applied for the estimation of the fluctuation of groundwater
table across the area and to delineate the groundwater table structure of pre and post monsoon.
Since kriging is a geostatistical interpolation technique which considers both distance and degree
of variation between known and estimated values. This method is an attempt to minimize the error
variance and set the mean of the prediction error to zero so that there is no over or under estimates
as it is a robust interpolation technique which derives weights from surrounding measured values
to predict values at unmeasured locations.
The figures shows the spatial distribution of groundwater developed across the study area.
The figure of pre-monsoon (fig. 24) and post-monsoon (fig. 25) shows the amount of Kriged
groundwater table and the third is the amount of fluctuation (fig. 26) across the area and fig. 27,
28, 29 shows the Standard deviation (Error) associated with the estimation of the groundwater
table. Fig.24 shows the distribution of ground water table during the pre-monsoon period. In this
map it can be seen that the water table towards the NW side of the area is at a higher level and
41
towards NE side is at a deeper level, this also confirms the topographical elevation of the area
which is also similar to this and dependence of the groundwater table on the topographical
elevation . The NW side has a higher elevation and NE is at a lower elevation. When compared
this map with Post-monsoon Kriged map it can be seen that the recharge pits have shown a positive
trend and the Kriged Map shows, the fluctuation in water level is taking place due to rise in
groundwater table.
48
7.5 Results and Discussion
From the Kriged Estimate Fluctuation map it can be noticed that the NW (0.78m) part is
having the least rise in water table than the NE (5.3m) part. NE part having high fluctuation also
highlights that the draft being done by the pump house which is pumping out the water at regular
interval and it shows a depression structure being developed there. Furthermore it is observed that
the kriged standard deviation (error) map shows that the error associated with the Kriged estimate
in all the three maps. The KSD map shows that the maximum error is at the NE side where the
water is being drafted regularly and the depression is getting created also in the fluctuation KSD
map .The red zone are showing the maximum error and the dark blue is showing the minimum.
This also confirms that the recharge pits located at the Northern and NW part of the study area is
controls the error. Furthermore it can be seen where ever the recharge pits are present the error is
less and it gradually increases when moved away from the recharge pit.
To study the flow direction of the groundwater during different period, different contour
maps were developed on the Kriged surfaces to visualize and simulate the groundwater scenario
in the subsurface region of the ISM campus. The figures from 30 to 35 shows and gives the
direction of flow of subsurface water during the pre-monsoon and post-monsoon periods. It can be
noticed that there is not much difference in the flow direction and is following the topographic
elevation system.
The water table contour map from figure 30 to 35, it can be observed that the flow direction
is from NW to NE and SW divergence can also be observed in the central ridge portion i.e.
topographically controlled groundwater flow. In the north eastern part a groundwater trough with
central flow is noticed from the spacing of the water table contour map. A generalized estimate of
the hydraulic characteristics can also be made.
There is higher transitivity of the fractured aquifers which are indicated by the
comparatively larger spacing in the contour lines of the NW, Western and South Western part of
the campus.
49
Fig: 30 Kriged estimate contour map of Pre-monsoon groundwater table
Fig: 31 Kriged estimate contour map of Post-monsoon groundwater table
50
Fig: 32 Kriged estimate contour map of Fluctuation in groundwater table
Fig: 33 Kriged SD contour map of Pre-monsoon groundwater table
51
Fig: 34 Kriged SD contour map of Post-monsoon groundwater table
Fig: 35 Kriged SD contour map of Fluctuation in groundwater table
52
It can be seen that the level of water table is higher in the NW part than the NE part. It can
also be visualized that the flow of ground water is moving out of the ISM when we see from the
center of the map and there is a development of ridge like structure which is controlling it, when
we compare this with the topographic elevation of the area it can be verified that the center part
i.e. The Heritage Building and surrounding are at a higher elevation i.e. from there the ground
water is flowing out of the campus towards the SW and also towards the NE part of the area where
the depression is being created.
Mean of the
actual and
estimated=0.002
R=0.9373
Fig: 36 Regression line of pre-monsoon
In order to verify the accuracy of the variogram models fitted, that was used to estimate
the groundwater table for all the three pre, post and fluctuation of the figures 36, 37 and 38 shows
the graph and the regression line between the observed and the estimated values of ground water
table during the pre-monsoon and post-monsoon period and of the fluctuation. The above graphs
shows the R values of Pre-post and fluctuation which are 0.937, 0.871 and 0.877 respectively. The
mean of the actual to that of estimated (i.e. 0.002, 0.005, 0.004) is also reliable and supporting the
unbiasedness constraint of Kriging (Goovaerts, 1997).
y = 0.7625x + 57.166
R² = 0.8787
228
230
232
234
236
238
240
242
244
246
248
220 225 230 235 240 245 250
Est
imat
ed V
alues
Measured Values (m)
Kriged Estimate Premonsoon
53
Mean of the
actual and
estimated=0.005
R=0.871
Fig: 37 Regression line of post-monsoon
Mean of the
actual and
estimated=0.004
R=0.877
Fig: 38 Regression line of fluctuation
y = 0.6107x + 94.288
R² = 0.7603
234
236
238
240
242
244
246
248
230 235 240 245 250 255
Est
imat
ed V
alu
es (
m)
Measured Values (m)
Kriged Estimate Postmonsoon
y = 0.6049x + 0.7706
R² = 0.7757
0
1
2
3
4
5
6
7
8
0 2 4 6 8 10 12
Est
imat
ed V
alues
(m
)
Measured Values (m)
Kriged Estimate of Fluctuation
54
However a little bias can be seen from the slope so ‘t’ on ‘r’ test were performed to determine the
significance of ‘r’ for all pre, post and fluctuation, the ‘t’ test was performed separately and was
found that the ‘r’ is significant in all the cases. The calculation is described below.
For Pre-monsoon
‘t’calc on ‘r’ = 𝒓√𝒏−𝟐
√𝟏−𝒓𝟐 = 18.40
‘t’table (α=0.05, ν=n-2, q=1-α) = 1.68
(i) If tcalc ≤ ttable : H0 is accepted and r is insignificant
(ii) If tcalc ≥ ttable : H1 is accepted and r is significant
For Post Monsoon
‘t’calc on ‘r’ = 𝒓√𝒏−𝟐
√𝟏−𝒓𝟐 = 12.80
‘t’table (α=0.05, ν=n-2, q=1-α) = 1.67
(i) If tcalc ≤ ttable : H0 is accepted and r is insignificant
(ii) If tcalc ≥ ttable : H1 is accepted and r is significant
For Fluctuation
‘t’calc on ‘r’ = 𝒓√𝒏−𝟐
√𝟏−𝒓𝟐 = 11.90
‘t’table (α=0.05, ν=n-2, q=1-α) = 1.68
(i) If tcalc ≤ ttable : H0 is accepted and r is insignificant
(ii) If tcalc ≥ ttable : H1 is accepted and r is significant
55
Chapter 8
8. Groundwater Resource Assessment
8.1 Estimates of current Ground water Supply in ISM
As discussed above the current water scenario of water requirements in ISM and that there
is huge expansion plan is going on so the water demand is also rising at a rapid pace. This increase
in demand of water has increased the stress on the current bore wells and on the resources which
are drafting groundwater to meet the need. The current supply status of the water in the campus is
given in the Table 9.
Sr.No. Tube Well No. Location
Discharge/Hr.
(Litre)
Pumping
Hrs
Total
Discharge/ Day
1 Dug Well No. 1 Near Ruby hostel 15000 10 150000
2 Dug Well No. 2 Workshop Campus 12000 10 120000
3 Dug Well No. 3
Near Petroleum
Building 12000 10 120000
4 Dug Well No. 4 Staff Colony 8000 10 80000
5 Dug Well No. 5 Near UGC Colony 20000 10 200000
6 Dug Well No. 6 Near CME Building 20000 10 200000
7 Dug Well No. 7 Near GJLT Hall 8000 3 24000
8 Deep Bore Well-9 Staff Colony 12000 9 108000
9
Deep Bore Well-
10 Bamboo Garden 20000 12 240000
10
Deep Bore Well-
11
Beside Seismology
Observatory 20000 14 280000
11
Deep Bore Well-
12 Jasper Hostel 8000 10 80000
56
12
Deep Bore Well-
13 In Front Of Old EDC 8000 10 80000
13
Deep Bore Well-
14
SBI ISM Campus
Branch 8000 12 96000
14
Deep Bore Well-
15
Beside 150 Quarters GR
Side 8000 12 96000
15
Deep Bore Well-
16
EDC Extension
Building 8000 10 80000
Total 1954000
Total Consumption / Month 1954000x30= 58620000
Table: 9 pumping of groundwater in ISM
Here it can be seen that seven dug wells and eight tube wells are supplying 1954000 liters
per day but still ISM purchases 850000 liters per day from D.W. &S department to meet the
demand and pays a high amount of money. Also the depth of water table has a high impact on
pumping out as when the water table is at high depth the electricity consumed is more and the
energy needed is more which ultimately increases the cost of the water. The current energy
consumption status of ISM is given in Table 10.
Sr.No. Tube Well No. Location
HP
Rating
Pumping
Hrs /Day
Units
Cosumed/Day
1 Dug Well No. 1 Near Ruby hostel 7.5 10 55.95
2 Dug Well No. 2 Workshop Campus 7.5 10 55.95
3 Dug Well No. 3 Near Petroleum Building 15 10 111.90
4 Dug Well No. 4 Staff Colony 7.5 10 55.95
5 Dug Well No. 5 Near UGC Colony 15 10 111.90
6 Dug Well No. 6 Near CME Building 15 10 111.90
57
7 Dug Well No. 7 Near GJLT Hall 5 3 11.19
8 Deep Bore Well-9 Staff Colony 7.5 9 50.36
9 Deep Bore Well-10 Bamboo Garden 15 12 134.28
10 Deep Bore Well-11
Beside Seismology
Observatory 7.5 14 78.33
11 Deep Bore Well-12 Jasper Hostel 5 10 37.30
12 Deep Bore Well-13 In Front Of Old EDC 5 10 37.30
13 Deep Bore Well-14 SBI ISM Campus Branch 5 12 44.76
14 Deep Bore Well-15
Beside 150 Quarters GR
Side 5 12 44.76
15 Deep Bore Well-16 EDC Extension Building 5 10 37.30
Total 979.13
Total Consumption / Month 979.13x30 = 29373.90
Table: 10 Units consumed for drafting groundwater in ISM
When we calculate it yearly the water discharge from the ground water is 21.39 mcm and
the total expense of drafting this water comes around 1.07 million units which costs very heavy
amount, financially and also it generates heavy load on the energy point of view. To curtail down
this and to convert the ground water cheaper the best way is to decrease the water table depth
which has direct effect on the energy consumption. Also these artificial structures to recharge the
groundwater table has very long term effect and it can be very beneficial not to ISM but also to
the surrounding area. Moreover it has been observed in the surrounding area the old dug wells
which used to be dry during summers has water of about 1m in them and did not dried up.
8.2 Groundwater Resources Estimation Methodology
Ground Water Resource Estimation Methodology – 1997 (GEC’97) recommends two approaches
for groundwater assessment– (i) water level fluctuation method and (ii) norms of rainfall infiltration
method.
The water level fluctuation method is based on the concept of storage change due to difference
between various input and output components (application of groundwater balance equation). The input
58
refers to recharge from rainfall and other sources and subsurface inflow into the unit of assessment. Output
refers to the groundwater draft, groundwater evapotranspiration, and base-flow to streams and subsurface
outflow from the unit. Since the data on subsurface inflow/ outflow are not readily available, it is
advantageous to adopt the unit for groundwater assessment as basin/ sub-basin/ watershed, as the inflow /
outflow across these boundaries may be taken as negligible.
Thus, the groundwater resource assessment unit is in general watershed particularly in hard
rock areas where as in case of alluvium areas, administrative block can also be the assessment unit.
In each assessment unit, hilly areas (areas having slope greater than 20%) are to be identified and
deducted from the total geographical area as these are not likely to contribute to groundwater
recharge. Further, areas where the quality of groundwater is beyond the permissible limits for
irrigation purposes should also be identified and assessment should be made separately. The
remaining area after deleting the hilly area and separating the area with poor groundwater quality
is to be delineated into command and non-command areas. Ground water assessment in command
and non-command areas are done separately for both the monsoon and the non-monsoon seasons.
8.3 Groundwater Recharge
8.3.1 Monsoon season
The resource assessment during monsoon season is estimated as the sum total of the change in
storage and gross draft. The change in storage is computed by multiplying water level fluctuation between
pre- and post-monsoon periods with the area of assessment and specific yield. Monsoon recharge can be
expressed as -
R = (h x Sy x A) + DG
Where,
h = rise in water level in the monsoon season,
A = area for computation of recharge,
Sy = specific yield,
DG = gross groundwater draft
The monsoon groundwater recharge has two components – rainfall recharge and recharge from other
sources. Mathematically it can be represented as –
59
R (Normal) = Rrf (normal) + Rc + Rsw + Rt + Rgw + Rwc
Where, Rrf is the normal monsoon rainfall recharge. The other sources of groundwater recharge during
monsoon season include Rc, Rsw, Rt, Rgw, Rwc which are recharge from rainfall, seepage from canals, surface
water irrigation, tanks and ponds, groundwater irrigation, water conservation structures respectively.
The rainfall recharge during monsoon season computed by Water Level Fluctuation (WLF)
method is compared with recharge estimated by Rainfall Infiltration Factor (RIF) method based on rainfall
infiltration factor. In case if the difference between the two sets of data are more than +20% , 1.2 times the
value estimated by RIF method is taken and if the difference is less than -20%, then 0.8 times the value
estimated by RIF method is taken. In case, the difference between the two sets of data remains between
+20% and -20%, monsoon recharge from water level fluctuation (WLF) is adopted.
8.3.2 Non-Monsoon season
Rainfall recharge is computed by using Rainfall Infiltration Factor (RIF) method during non-
Monsoon season. Recharge from other sources is then added to get total non-Monsoon recharge. In case of
areas receiving less than 10% of the annual rainfall during non-monsoon season, the recharge due to rainfall
may be taken as zero.
Total annual groundwater recharge
The total annual groundwater recharge of the area is the sum-total of monsoon and non-monsoon
recharge. An allowance is kept for natural discharge during non-monsoon season by deducting 5% of total
annual groundwater recharge, if WLF method is employed to compute rainfall recharge during monsoon
season and 10% of total annual groundwater recharge if RIF method is employed. The balance groundwater
available accounts for existing groundwater withdrawal for various uses and potential for future
development. This quantity is termed as Net Ground Water Availability.
Net Ground Water Availability = Annual Ground Water – Natural discharge during non-
Recharge monsoon season
An attempt has been made to estimate the replenishable groundwater resource within the campus
using the norms of Ground Water Resource Estimation (GEC 1997) methodology with the help of
60
Kriged estimate of the fluctuation of the groundwater table. The volume is calculated from the mean Kriged
value of the fluctuation of the entire area.
The total replenishable volume of water or dynamic groundwater resource is calculated by the below
formulae
Volume of water recharge = (Area x fluctuation x 0.03) + Total draft during the period
Here, 0.03 is the specific yield considered for hard rock as per GEC, 1997
Hence, (60 x 56 x 25 x 25 x 2.29 x 0.03 = 144270 m3) + Total Draft
The volume of water recharged is 144270 m3 x 1000 = 144,270,000 liters
As given in Table 9 the draft related to consumption from ground water for the study period is 19,54,000 x
12 x 30 = 703,440,000liters and as calculated the recharge volume in groundwater above the excess water
used can be calculated from the subsurface
703,440,000 + 144,270,000 = 847,710,000 liters
Here it can be seen that about 83% of total volume of water available is being used and still the
campus area is surplus of groundwater which is around 17%.It should also be noted that this much of draft
is sustainable and can be calculated only when this study is continued by collecting more data in the coming
years and then only the trend of the groundwater table can be developed which will be key to predict the
groundwater fluctuation in the long run. By observing the current data water consumption and correlating
by collecting the same in future and further studies can reveal more accurate and effect of these recharge
pits.
8.3.3 Norms for Estimation of Recharge
GEC’97 methodology has recommended norms for various parameters being used in groundwater
recharge estimation. These norms vary depending upon water bearing formations and agro-climatic
conditions. While norms for specific yield and recharge from rainfall values are to be adopted within the
guidelines of GEC’97, in case of other parameters like seepage from canals, return flow from irrigation,
recharge from tanks & ponds, water conservation structures, results of specific case studies may replace the
adhoc norms.
61
8.4 Ground Water Draft
The gross yearly groundwater draft is to be calculated for irrigation, domestic and industrial uses.
The gross groundwater draft would include the groundwater extraction from all existing groundwater
structures during monsoon as well as during non-monsoon period. While the number of groundwater
structures should preferably be based on latest well census, the average unit draft from different types of
structures should be based on specific studies or ad-hoc norms given in GEC’97 report.
62
Chapter 9
9. Groundwater Quality in ISM
9.1 Chemical analysis of groundwater
The importance of ground water quality has become increasingly recognized as
development of ground water continues to expand in British Columbia. Monitoring of ground
water quality is becoming more important because of contamination concerns and development of
new equipment and techniques for measuring contaminants in minute concentrations.
Although ground water is generally less susceptible to contamination than surface waters it is
usually more highly mineralized in its natural state. As water moves slowly through the ground it
can remain for extended periods of time in contact with minerals present in the soil and bedrock
and become saturated with dissolved solids from these minerals. This dissolution process continues
until chemical equilibrium is reached between the water and the minerals with which it is in
contact. The types and relative concentrations of the chemical constituents in ground water provide
information on the evolution of ground waters, age (residence time), and solubility, rates of
movement, flow history and sources of recharge. Older ground waters for example are generally
more mineralized than younger ground waters. Fresher ground waters are normally associated with
recharge areas whereas ground waters in discharge areas are more mineralized. Ground waters can
be classified according to the most dominant percentage of cations and anions being present based
on concentrations in equivalents per million [epm] (e.g., calcium-magnesium bicarbonate type).
9.2 Hydro chemical findings in ISM campus
The groundwater of the study area is mildly alkaline in nature with average pH value of
7.95. No sample contains carbonate but are characterised by the presence of bi-carbonate. The
maximum concentration of HCO3 was found as 344 mg l-1.
The value of electrical conductivity (EC) is from 202 to 1206 µS Cm-1 at 25oC which indicates a
wide variation in dissolved constituents.
63
In general, the quality of groundwater in terms of Total Hardness as CaCO3 has been found as
moderately hard to very hard. The maximum concentration of Ca has been found as 176 mg/L
and that is of Mg has been observed as 74 mg/L.
The concentration of Na ranged from 13 mg/L to 59 mg/L with an average of 40 mg/l and K was
found in the range from 1 mg/L to 9 mg/L with an average of 03 mg/L.
The concentration of Chloride in all of the ground water samples has been found to be within the
desirable limit for drinking purpose by BIS 2012. The maximum concentration of chloride has
been found as 163 mg/L. None of the analyzed sample showed Nitrate concentration higher than
the permissible limit of 45 mg/L and ranged from traces to 43 mg/L.
Concentration of Sulphate ion ranged from 8 to 110 mg/L. Fluoride ion concentration varied
from Traces to 1.19 mg/L with an average value of 0.41 mg/L. Phosphate has not been detected
from any of the sample. The silicate concentration was in the range of Traces to 17 mg/L.
As per the Na% value, Residual Sodium Carbonate and Sodium Adsorption Ratio all the analyzed
samples have been found safe and of excellent category.
Mostly no major threat has been identified according to analyzed major parameters from drinking
water perspective (Drinking water specification: BIS, 2012). All the analyzed samples have also
been found suitable for use in irrigation and allied purposes.
64
No. of Samples = 15
Parameters BIS Permissible Limit* in absence of alternate
source
No. of Sample. > D.
L.
Turbidity 10 -
pH NR ND
EC - ND
TDS 2000 5
TH 600 2
Alkalinity 600 9
Ca2+ 200 1
Mg2+ 100 8
Na+ - -
K+ - -
HCO3- - -
CO32- - -
Cl- 1000 ND
NO3- NR ND
SO42- 400 ND
F- 1.5 2
Table: 11 Groundwater quality in ISM.
65
Sr.no. Place/ Block Structure pH EC TDS TH CO3 HCO3 Ca Mg Na K Cl NO3 SO4 F PO4 SiO2
1 Ruby Hostel
Annexe, ISM
Recharge
Well 8.04 728 473 195 ND 240 36 26 72 6 67 41 71 0.86 BDL 13
2 Shanti Bhawan,
ISM
Recharge
Well 8.16 698 454 215 ND 252 30 34 44 3 39 16 72 0.92 BDL 12
3 Type II Qtrs, ISM
Recharge
Well 7.93 629 409 205 ND 215 32 30 41 4 89 7 39 0.57 BDL 15
4 Amber Hostel,
ISM
Recharge
Well 7.83 720 468 220 ND 326 20 41 55 2 35 3 56 0.00 BDL 15
5 Sapphire Hostel,
ISM
Recharge
Well 7.90 492 320 210 ND 148 32 19 22 8 14 29 71 1.06 BDL 2
6 Student activity
centra, ISM
Recharge
Well 8.02 660 429 210 ND 271 28 34 38 4 53 3 38 0.00 BDL 10
7 Central Workshop,
ISM Dug Well 8.11 520 338 160 ND 209 28 22 34 4 35 5 33 0.97 BDL 12
8 Environment Marg,
ISM Dug Well 8.10 202 131 80 ND 92 18 9 13 2 14 0 9 0.46 BDL 1
9 Staff Colony, ISM Dug Well
7.96 218 142 85 ND 105 18 10 14 2 18 0 8 0.00 BDL 0
10 CGWB, EW, ISM Bore Well
7.66 886 576 200 ND 308 38 45 59 6 18 18 85 0.00 BDL 10
11 Near Petroleum
Engineering, ISM Dug Well 7.91 904 588 235 ND 344 34 36 58 2 36 8 66 0.00 BDL 14
12 Thakurkuli, Dahiya Dug Well
7.88 1102 716 415 ND 277 44 74 54 2 89 39 107 0.62 BDL 17
13 Main Road,
Saraidhela Handpump 7.93 1206 784 445 ND 185 176 1 59 3 163 43 111 0.83 BDL 16
14 Jagjeevan Nagar,
Dhanbad Bore Well 7.87 819 532 285 ND 178 34 49 33 9 121 12 78 0.16 BDL 12
15 Bank More,
Dhanbad Dug Well 7.95 289 188 90 ND 117 18 11 27 1 21 9 19 1.19 BDL 4
Min
7.66 202 131 80 ND 92 18.00 1.21 13.31 1 14.18 0.00 8.09 0.00 BDL 0
Max
8.10 1206 784 445 ND 344 176.00 74.11 59.19 9 163.07 43.29 110.55 1.19 BDL 17
Std Dev
0.12 407 264 145 ND 98 52.90 25.66 20.01 3 57.09 16.48 42.66 0.45 BDL 10
Avrage
7.91 703 457 229 ND 201 47.50 29.35 39.75 3 59.93 16.14 60.33 0.41 BDL 10.00
ND = Not
Detected
BDL = Below
Detection Limit
Table: 12 Location wise groundwater quality in ISM
66
Chapter 10
10. Groundwater Management
Since we know ISM is developing artificial recharge system it should also be noted that
management of the ground water is very crucial for the success of this system. The drafting of
ground water should be done keeping in mind where there are more boreholes and water is
getting recharged more i.e. from the NW side where there is high cluster of recharge pits. The
recharge pits should be cleaned and maintained well so that there is no blockage and there is
no resistance in the process of recharge during the rainy season. Waste water and Sewage water
management can also be very helpful in this regard as we can recycle the waste water and reuse
it for different needs of sanitation and domestic use like for gardening, flushing, cleaning etc.
which can minimize the use of groundwater and restrict its use to drinking purpose only. It can
also be observed that the campus is under construction and high volume of open space grass
land is getting covered by roads, buildings and others concrete structure which ultimately
increases the surface runoff and in the coming years it can be more than 50% of the total area.
So to compensate it, certain drain system can be developed that can be used as recharge
connection to the recharge pits during rainy seasons. The beginning is made in this direction to
certain buildings but later it can be extended to other rooftops of buildings and can connect
them to the recharge pits and ultimately decreasing the total runoff from the campus area. The
treatment of waste water is expensive but considering the future demand of water in ISM it can
be started at a small scale which can later be balanced and improved.
67
Chapter 11
11. Conclusion
The study showed a spatial relation of increase in water level and structure developed
due to the recharge of water through the recharge pits. Kriging methods with cross validation
techniques were applied to assess the accuracy of the chosen variogram model and in
estimating the ground water level increase after the monsoon. It shows a low nugget (Table 6,
7, 8) indicating that it is very regular or of homogeneous character. Table 6 (C0/C0+C)
3/26=0.115 and the others also show the same character even the values are different for pre- ,
post and fluctuation, that indicates it is very favored by its nugget effect. Range for all is
comparatively high for all the periods and the values are co-relatable for longer distances. The
search area taken was not beyond the range and was taken near so that to incorporate maximum
number of points. Thus, the value C0, C and Range (a) characterizes the geostatistical
parameters. Results of kriging revealed that ground water level of the study area increased by
2.29m (Kriged mean) which supports the kriging methods as a beneficial tool for detecting the
critical regions where ground water is to be used in more sustainable way. This also reveals the
management of water in hard rock terrain in a more efficient way and also develop a better
management strategies of ground water resources. This study gives an idea of conducting water
harvesting system in this type of regions to recharge the ground water artificially. The
assessment of the groundwater reveals that there is a necessity of artificial recharge system. It
also advocates that the artificial recharge system to be more efficiently used to counter the
future problems or to avoid the water crisis in the near future. From this study it is seen that a
localized structure is developing as the area is very small. The volume of water consumed is
around 74% and 16% of total resource is being conserved but still it needs to be improved as
the demand of water is increasing day by day in the campus.
68
References
(i) Sayed Hamid Ahmadi and Abbas Sedghamiz. Geostatistical Analysis of Spatial and
Temporal Variations of Groundwater Level, Environmental Monitoring and
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(ii) D. Kumar and S. Ahmed (2003), Seasonal Behaviour of Spatial Variability of
groundwater level in granitic aquifer in monsoon climate, Current Science, 84, pp.
188-196.
(iii) S. Sahoo and M.K. Jha. Analysis of Spatial variations of Groundwater Depths Using
Geostatistical Modelling, Published in International Journal of Applied Engineering
Research, Volume-9, Number 3 (2014) pp. 213-322.
(iv) Goovaerts, P. (1997). Geostatistics for Natural resources evaluation. New York:
Oxford University Press.
(v) R. H. Sawkar. Groundwater Development and Rainwater Harvesting in Greater
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