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INTERNATIONAL JOURNAL OF GEOMATICS AND GEOSCIENCES

Volume 3, No 2, 2012

© Copyright 2010 All rights reserved Integrated Publishing services

Research article ISSN 0976 – 4380

Submitted on September 2012 published on November 2012 321

GIS based mapping and environmental impact of Wetlands changes in a

Riverine district of Bangladesh Siddiki, Ubaydur Rahaman., Islam, Md. Nurul

Department of Geography and Environment, Jahangirnagar University,

Savar, Dhaka-1342, Bangladesh

[email protected]

ABSTRACT

This research is concerned with the GIS based mapping and change of areal extent of

wetlands within two different periods and to identify the causes of change and impact

assessment of wetland change in the study area. This research was conducted at a micro

scale level at Daulatpur upazila in Manikganj district. It can be seen that development

activities as well as increasing population have made a huge difference in wetlands change

which are drying up rapidly at present time in the study area compared with the past twenty

years or more. Satellite images of two different periods were analyzed using related software.

A questionnaire was conducted to investigate the attitude of the cross-section of people in

five unions of the study area. GPS survey and visual observation was also made to verify

satellite image information. All collected and gathered primary and secondary data have been

processed manually and by using GIS Software (ERDAS Imagine, ArcGIS 9.2, Arc View 3.3,

and Image Analysis1.0). It is found that in 1990, total area of wetland was about 21.76% of

the study area has gradually decreased and reached its lowest point was about 20.53% in

2004. From 1990 to 2004, the total area of wetlands decreased to near about 1 sq. mile. The

factors responsible for wetlands changes are riverbank erosion, flood and sedimentation,

expansion of human settlement, industrialization, unplanned development activities,

overexploitation, agriculture and climate change. Degradation of wetlands has created several

impacts on drainage system, loss of natural water reservoirs, loss of aquatic animals and

fishes, increase in the occurrence of flooding, loss of natural soil nutrients, cropping patterns

and amount of production, occupations and transportation facilities. Based on these findings,

a number of recommendations have been put forward for conservation, preservation, and

management of wetlands to the concern authorities.

Keywords: Bangladesh, Wetlands, Changes, Management, Environmen, Micro Scale,

Drainage, Flood, Sedimentation, Conservation, Riverbank, Erosion, Riverine, GIS, Mapping.

1. Introduction

Wetlands are functioning as kidney of ecosystems and the courage lines of the nation;

however these are under several anthropogenic terrorizations. It supplies massive services to

the human being and the environment. A Wetland is an ecosystem that arises when

inundation by water produces soils dominated by anaerobic processes and forces the biota,

particularly rooted plants, to exhibit adaptations to tolerate flooding (Keddy, 2000). A

substantial amount of wetland has already been lost. The degradation of wetlands has created

numerous problems including decrease and extinction of wild flora and fauna, loss of natural

soil nutrients, water reservoirs and of their subsequent benefits. They have affected on

various traditional occupations, socio-economic conditions and cultural activities. Wetlands

are described as the kidney of landscape because of its functions; it is also denoted as

GIS based mapping and environmental impact of Wetlands changes in a Riverine district of Bangladesh

Siddiki, Ubaydur Rahaman., Islam, Md. Nurul

International Journal of Geomatics and Geosciences

Volume 3 Issue 2, 2012 322

biological supermarkets because of extensive food webs and rich biodiversity, they support

(Mitsch & Gosselink, 1993). Wetlands are also unique for their rich biological diversity; that

make wetlands are important to society for its yields and values. Wetlands not only support

wildlife (flora and fauna), but also play a vital role in flood regulation and moreover they

produce fisheries, food grains, wildlife and forest resources (Akonda, 1990). Bangladesh

possesses enormous wetland areas, and indeed during the rainy season, about half of the

country could be classified as wetland. This study was accompanied in Daulatpur upazila of

Manikganj district which is heavily affected by flood and riverbank erosion during rainy

season where there had lots of river, khal, beel, pond, and dobas are declined since of

seasonal flood, riverbank erosion, development activities and increasing human occupancy.

So present study try to observe the different categories of wetlands and its areal extent by

mapping, causes of its change detection over a certain period of time and its impact on

environment and livelihood in the study area.

Aim and objectives

The aim of this research to acquire relative knowledge about wetlands changes detection

within a certain period of time, causes of changes, and its impact analysis are accumulate by

mapping using GIS. The objectives of this research are as follows:

1. To identify and mapping several categories of existing wetlands and their areal extent

in the study area;

2. To find out the causes of change detection of wetlands within a certain period of time;

and

3. To point out the impact of wetlands changed on ecosystems and livelihood in the

study area.

2. Materials and method

For the purpose of this study the data has been collected through two means primary data

sources include formal questionnaire survey and informal interview or questionnaire survey.

This was complemented by a number of the qualitative techniques. Several investigation was

conducted in selected five unions of study area out of eight unions in the form of

questionnaire survey, GPS survey and visual observation was also made to verify satellite

image information. All collected and gathered primary and secondary data have been

processed manually and by using computer to manipulate the data accordance with the

objectives and guidelines of the research. For remote sensing analysis, two satellite images

(Landsat TM image of 1990 and Landsat TM image of 2004) were used. The image

processing and analysis has been carried out using ERDAS IMAGINE 8.4 image processing

software. Data on wetland features have been extracted using ERDAS IMAGINE software

and presented in tabular and pictorial form by Microsoft excel software. GIS analysis has

been carried out using ArcView3.3 software and the map output has been generated using

ArcView 3.3 and ArcGIS 9.2. GIS Software (ERDAS Imagine, ArcGIS 9.2, Arc View 3.3,

and Image Analysis1.0) did remote sensing data interpretation and classification, preparation

maps, statistics generation, and analysis as well as visual presentation.

Study area

Daulatpur upazila of Manikganj district (Map-1) has been selected as study area. Daulatpur is

located between 23º54ánd 24º02´ north latitudes and between 89º 41ánd 89º 57éast





longitudes which is bounded on the north by Chowhali Upazila of Sirajganj zila and Nagarpur

upazila of Tangail zila, on the east by Nagarpur upazila of Tangail zila and Saturia upazila, on

the South by the Ghior Upazila and Shivalaya upazila and on the west by Bera upazila of Pabna

zila. The entire area is allowed low-lying flood plain of Jamuna and young Brahmaputra

River. The Upazila occupies an area of 216.24 sq. km having of 8 unions, 141 mauzas, and

186 villages (Population Census-2001).

Map 1: Location of the study area

Wetland in Daulatpur Upazila

The wetland ecosystems are very important to the economy and life of the people of

Bangladesh. An attempt has been made to understand the changing pattern of wetland of

Daulatpur Upazila. In order to classify the wetland of the Daulatpur Upazila, the satellite

images have been used with the additional information from the key informants. Four

different types of landuse have been identified from satellite image. Of them, wetlands were

the major concern, which include permanent wetlands, permanent and seasonal waterway.





Areal extent of wetlands and its associated landuse in the study area

For the purposes of measurement of areal extent of wetland of Daulatpur upazila, the satellite

images were interpreted and analyzed and classified these images into four different classes.

The areal extent of these land use features are given below (table-1).

Table 1: Areal extent of wetland and other landuse features and its percentage

Land Use Types

Land use Area (sq. mile) & its percentage

1990 2004

Land use Area % of total

area

Land use Area % of total

area

Wetland 16.42 21.76 15.48 20.53

Agricultural land 22.85 30.30 23.05 30.56

Settlement Area 11.17 14.74 15.37 20.38

Exposed Area 25.04 33.20 21.50 28.51

Source: Area computed from satellite image of 1990 and 2004

3. Results

Spatial changes of landuse in different years

Satellite images of 1990 and 2004 are used to prepare landuse and land covered maps for the

study area. Both maps are prepared based on landuse and land covered type. Table-1

demonstrates year wise distribution of landuse of Daulatpur Upazila.From above table, it is

shown that in 1990, total area of wetland was about 16.42 sq. miles, which is 21.76% of the

total area. Agricultural land was 22.85 sq. miles; exposed area was the highest land covered

which is about 25.04 sq. miles. The lowest land covered area was the settlement area, which

is about 11.17 sq. miles. The table also revealed that in 2004, the total area of wetland was

15.48 sq. miles, which is about 20.53% of the total area. The highest land use covered was

agricultural land and lowest was settlement area. Wetland area and settlement area was about

to same in the year of 2004 landuse area.

Table 2: Change in landuse areal extent in the study area for the year of 1990 & 2004

Landuse

Types

Area (sq. mile) &

its percentage Change in Areal Extent

Remarks

1990 2004 From 1990-2004

Landuse

Area

Landuse

Area

Area (sq. mile)

Increase/

Decrease

In context

of

total area

(%)

In context

of Landuse

(%)

Wetland 16.42 15.48 0.94 1.23 5.67 Decreased

Agricultur

al land 22.85 23.05 0.2 0.26 0.87 Increased

Settlement 11.17 15.37 4.2 5.57 37.60 Increased

Exposed

Area 25.04 21.50 3.54 4.69 14.18 Decreased

Source: Area computed from satellite image of 1990 and 2004





From the above table, it can be found that about the land use changes in the study area in two

different periods. This table also demonstrates the change in areal extent in context of total

area and in context of landuse area.

Change in wetland areal extent

In 1990, the total area of wetland was 16.42 sq. miles, which decreased to 15.48 sq. miles.

The total decreased area was 0.93 sq. miles, which is 1.23% in context of total area and

5.67% in context of landuse area.

Source: Satellite image analysis of 1990 & 2004

Figure 1: Areal extent change of wetlands in 1990 and 2004

Change in agricultural land areal extent

Agricultural landuse is another important land use of the study area that has been changed

since 1990 to 2004. In 1990, agricultural land of the study area was 22.85 sq. miles and in

2004, the amount was 23.05 sq. miles under agriculture and other vegetation.


Figure 2: Areal extent change of agricultural l land in 1990 and 2004

From the figure, it can be said that, the agricultural land of the study area is increased at a

slower pace as comparison to settlement area. The agricultural lands’ being low-lying area is





susceptible to flood risk and often remains as water logged. However, with the scarcity of

food, the exposed fallow land areas are cultivated by the farmers to meet their necessary

foods and the percentage of agricultural land in two different periods was increased near

about only 1%.

Change in settlement area

The highest number of changed occurred during the period of 1990 to 2004 in Daulatpur

upazila was in case of settlement areal extent. With the passage of time, settlement area has

been changed quite a lot. In 1990, it was only 14.74% (11.17 sq. miles) of the total study area

but it increased in 2004 to 20.38% (15.37 sq. miles). The total area of settlement increased

4.2 sq. miles, which are about 5.57 % in context of total area and 37.60% in context of

landuse area.

From the figure-3, we can see that the settlement area increased 37.60% from 1990 to 2004.

This indicates the percentage of population increased along with other development activities

like industrialization, urbanization and also family dividation processed in rural as well as

urban areas. As the built up area of the study area has been increased at a very high rate

between the study period (1990-2004), and as the total area did not increase, so it can be said

that, water bodies of the both types (seasonal and permanent) as well as exposed area have

been changed into built up area.


Figure 3: Areal extent changes of settlement area in 1990 and 2004

Change in exposed area

Areal extent of exposed land of the study area decreased in highest percentages. In 1990, the

total area of exposed land was 25.40 sq. miles, which was the highest landuse coverage in

that particular year, and it decreased to 21.50 sq. miles in 2004.






Figure 4: Areal extent change of exposed area in 1990 and 2004

From the above figure we can see that, from 1990 to 2004, the total exposed area was

decreased about 3.54 sq. miles, which is 4.69% in context of total area and 14.18% in context

of landuse area. This is because of population pressure, infrastructure development and other

development activities. In 1988, a massive flood occurred which caused a big destruction in

case of riverbank erosion and also flood carried sand filled low land area and after that these

land become exposed land. However, with the passage of time, these exposed lands have

been converted to settlement area as well as agricultural land. Various graphs are given below

by calculating the above-tabulated data on landuse features:

Map 2: Wetlands and other landuse of Daulatpur upazila in 1990





Map-3: Wetlands and associated landuse of Daulatpur upazila in 2004

From the above discussion two different land use maps of two different years were produced

and another index map for both landuse map also shown the changes of major wetland areal

extent which are presented below:

Map-4: Wetlands of Daulatpur upazila in 1990





Map-5: Wetlands of Daulatpur upazila in 2004

Impacts of wetland change

Wetlands resources have suffered significantly from the impacts of a rapidly increasing

human population, together with some other causes like riverbank erosion, flood and

sedimentation, expansion of human settlements, urbanization and industrialization, unplanned

development activities etc. The impacts of human interfaces has been damaging to the fragile

ecosystems and sustainability of the wetlands. Apart from changes in the landuse pattern,

increased human activities in the wetland areas have put on pressure on wetland ecosystem.

Extraction of aquatic vegetation in a large scale has caused several problems in the wetland

biodiversity. This has also contributed to the decline of fishes and aquatic mammals. Impacts

of wetlands changed as observed in the study area are shown the following hierarchical flow

chart (Figure 9). The impacts of wetland change are categories into two sectors. These are

physical and human sector. The impact of wetlands change is discussed below:

Impact on physical sectors

Hydrological sectors

Wetlands change of Daulatpur Upazila brings the most serious impacts upon its hydrological

sector. Hydrological condition of the study area has been changing gradually with the

increase of land filling areas in low-lying part of the study area. Impacts upon hydrological

condition of the study area can be described as follow:

Impact on drainage system

There were a large number of canals, lakes, and depression in the study area that carried excess

rainfall water from the study area to for a way through its surrounding rivers. However, at

present unplanned development activities, the drainage system of the study area is in vulnerable





condition. From the satellite images of 1990 and 2004, it can be observed that most of the low

lying parts of the study area have been filled up which were very important for the drainage

system of the study area. A vast area of the upazila is filled up due to unplanned development

activities.

Loss of natural water reservoirs

The study area is endowed with plenty of surface and groundwater resources. The surface water

resources comprise water available from flowing rivers and static water bodies as ponds, beels,

and haors. Natural water reservoirs degraded due to change in wetland environment.

Reoccurring flood and land filling reduces the water storage area. Each flood carries a huge

amount sand, silt, and clay, which filled relatively depressed area. Except this, development

activities and unscientific agricultural cultivation leads loss of natural reservoirs. As a result,

the catchments losses the capacity to retain the excess runs off generated by heavy rainfall.

Impact on groundwater source

As the study area developments activities increased rapidly, consequently the cemented area

increased due to residential or other purposes. For this reason, rainwater cannot come in touch

with open space soil and thus does not go to underground through the soil particles. As

infiltration rate of the study area decreases, the moisture, and fertility of the soil of the study

area has been decreasing day by day. For the same reason, ground water level decreases

consequently to that suffers the people from in adequate water supply.

Loss of aquatic flora

Wetlands degradation leads loss of aquatic flora. Many kinds of aquatic plants enriched the bio-

diversity of the study area. However, at present low lying parts and water bodies of the study

area dried up. As a result, many kinds of plants are losing like Shapla, Shaluk, Padda, etc that

were available at all over the place but are not observed now. If this trend goes on, it will be

great loss to the wetland bio-diversity. Floral composition includes trees, shrubs and aquatic

vegetation (e.g. water hyacinth, lotus, water lily) are also in vulnerable condition.

Table 3: List of aquatic flora found in wetland of study area

A. Attached with substratum/Soil

a. Emergent

Sl.

No

Local name Scientific name Status in different year Use

1990 2004

1 Nalkhagra Phragmites karka VC C Fuel

2 Dholkalmi Ipomea fistulosa VC R Fuel

3 Kachu Colocasia esculenta VC C Vegetable

4 Sola/Hogla Aeschynomene sp VC R Fuel

5 Keshordam Ludwingia adscendens VC E Cattle feed

6 Bilkochu Monochoria hastate VC R Vegetable

7 Biroipata Polygonum plebejum VC E Vegetable

8 Kalmisak Ipomea aquatica VC C Vegetable

9 Helencha Enhydra fluctuans VC C Vegetable

10 Malencha Enhydra sp VC E Vegetable

11 Singara Trapa bispinosa VC E Food

12 Durba Cynodoh dactylon VC C Cattle feed

b. Leafy floating

1 Shapla Nymphaea sp VC R Vegetable





2 Padda Nelumbo nucifera C R Vegetable

3 Ghechu Apongeton sp VC E Vegetable

4 Kalmi Ipomoea aquatica VC C Vegetable

c. Submerged

1 Patajhaji Cerateophylum sp VC E Cattle feed

2 Kerali Crytocoryne spiralis VC E Cattle feed

B. Free floating

1 Kachuripana Eichhornia sp VC C Cattle feed

2 Khudipana Lemna sp VC E Cattle feed

3 Kuripana Pistyia strtiotes VC E Cattle feed

C. Aquatic plants

1 Hijal Barringtonia accutangula VC R Medicine

2 Barun Crataeva murvala VC E Medicine

3 Gab Diospyros peregina VC R Wood

Source: Questionnaire survey, March, 2010

[Code Status: VC= Very Common; C= Common; R= Rare, ED=Endangered; E=Locally

Extinct]

There were 12 emergent, 4 leafy floating, 2 submerged, 3 free floating and 3 aquatic plants

found in the study area (table 6.1). Of them only seven types of aquatic flora are common at

present and the rest of the aquatic flora are rare (7) and locally extinct (10).

Loss of aquatic animals and fishes

Like other water bodies all over Bangladesh, the water bodies of the study area were enriched

with many kinds of fishes. However, with the expansion of built up area, and many chemical

fertilizer, and pesticide are used in the agricultural activities and for wetland transformation,

these fishes and other aquatic animals are now under great threatening condition. As a result,

many kinds of fishes and aquatic animals are now destroyed and many are endangered. It will

bring a great harm or imbalance situation to our natural ecosystem.

Table 4: List of aquatic mammals

Sl.

No


1990 2004

1 Shamuk Pila globosa VC ED Food

2 Jhinuk - VC R Food

3 Kasim Menlanocchelys tricarinanta VC R Food

4 Kakra - VC VC Food

5 Kotkoti Bang Euphlyctis cyanophyctis VC R Food

6 Sona bang Hoplobatrachus hgrus VC R Food

7 Mach ranga Halcyon smyrents VC ED Food

8 Jangli has - VC R Food

9 Pati has - VC R Food

10 Bok(whit) Ardea cinere VC R Food

11 Bok(ash) Ardeola graii VC R Food

12 Knai Bok Leptoptilos Javancicus VC C Food

13 Kak Bok Nettapus VC C Food

14 Bali has Caomandelianus VC ED Food

15 Pan kuri Phalacrocorax niger VC R Food

16 Uodbiral Aonyxcinerea VC R Food

17 Sorali Dendrcyanazavanica VC ED Food





18 Kora Gallicrexcinerea VC C Food

19 Cill Haliastur Indus VC R Food

20 Dura sap Xenochrophispiscator VC VC Food

21 Matiashap Xenochrophiscinerea VC ED Food


[Code Status: VC= Very Common; C= Common; R= Rare, ED=Endangered;]

From the table-4 it can be seen that in the past all the aquatic mammals was very common in

the study area but after fourteen years these mammals are mostly rare in number (11), few are

common (3), few are in endangered (5) and only two types of mammals are present. Due to

commercial using of some aquatic fauna such as Jahinuk and frog causes their availability rare

in the study area. Jhinuk is mainly used as poultry feed as a source of calcium (Ca) and

different types of frogs are now being captured for exported abroad. If this process continues

then within new twenty years or more than that time aquatic mammals will not be found in the

study area.

Table 5: List of fishes of the study area

Sl.

No


1990 2004

1 Rui Labeorohita VC C Food

2 Katal Catla catla VC C Food

3 Boal Wallago atta VC C Food

4 Shing Heterpneustes fossilis VC R Food

5 Koi Anabous testusineus VC R Food

6 Taki/Ladi Channa punctatus VC C Food

7 Khoilsha Coilsha fasciants VC R Food

8 Tengra Gagata Gagata VC R Food

9 Golsha Mystus tengra VC E Food

10 Tatkina Cirrhinus reba VC E Food

11 Baila Glossogobius VC ED Food

12 Meni/Vedaira Nandus nandus VC ED Food

13 Shol Channa striatus VC C Food

14 Potka/Tepa Tetraodon cutcutia VC R Food

15 Mirka Cirrhinnus mrigala VC R Food

16 Gutum Lepidocephalus sp VC R Food

17 Kalibaos Labeo calbaus VC R Food

18 Shol Tor tor VC C Food

19 Gojal Channa maruius VC R Food

20 Chang Channa orientalis VC R Food

21 Guraicha Nematopalaenmon

tennuipes

VC C Food

22 Icha Macrobrachium sp, VC C Food

23 Chanda Chanda sp VC E Food

24 Kajli Ailichthy punctata VC E Food

25 Batai Pseudeuttropius VC R Food

26 Katchki Corica soborna VC R Food

27 Chapila Oreochromis mossambica VC R Food

28 Bujuri Bagarius VC R Food

29 Baim Macrognathus aculeatus VC R Food

30 Aeir Mystus aor VC C Food





31 Chital Notopteruschtala VC ED Food

32 Kanpona Oryzias melastigma VC E Food

33 Chela Chela baciala VC R Food

34 Mola Amblypharyngodon mola VC C Food

35 Sharputi Puntius sarana VC R Food


[Code Status: VC= Very Common; C= Common; R= Rare, ED=Endangered; E=Locally

Extinct]

The table-5 illustrates that almost all the freshwater fishes are available in the wetland of the

study area. Among the 35 species of fishes, Tengra, Shing, Magur, etc are found in the study

area. All the fishes were very common in the past but as time went and wetland transformed

into highland or settlement area the fishes are becoming the rare. About more than half of the

fishes are rare compared to past, three of them are in endangered and five of them are in

locally extinct. Expansion of human settlement, urbanization, industrialization, use of

pesticides in the agricultural land, sedimentation, overexploitation, unplanned development

activities in the area of wetlands are responsible for wetlands fish loss.

Change in biodiversity

Wetlands are very rich with floral and faunal biodiversity. Without these wetlands, the

aquatic flora and fauna would not be able to survive. In context of Daulatpur upazila,

biodiversity of wetlands are serious in threat. In low laying areas, large-scale settlement was

initiated at the mid-20th

century from surrounding densely populated regions and since then

the resources of the low lying or wetlands areas are being exploited at an increasing rate

causing adverse effects (Banglapedia-2007). Continuous large-scale exploitation of aquatic

vegetation and fruits like, Lily, hogla has caused serious degradation of the quantity and

quality of the habitat required for fish and other aquatic animals. The over exploitation of

aquatic plants, fishes and animals are foremost cause of extinction of aquatic plants, fishes

and animals. Another important cause is degradation of wetlands and fertilizer and pesticides.

Due to degradation of wetlands, the wetland converted into agricultural land. The depth of

water is reducing day by day as well as cultivation of HYV creates methane emission, which

deficits O2 (oxygen). It causes problems of respiration of fishes, aquatic animals. Aquatic

animals, fishes and animals remove the beels or water bodies and it appears rare in that area.

Environmental impacts

The environmental impacts of the transformation of the Daulatpur upazila wetlands are as

follows:

Increase in the occurrence of flooding

The expansion of development activities most of the water bodies have already been filled up

especially due to infrastructural and residential purposes. Hence, in the monsoon when most

of the rainfall occurs, the study area wetlands having their limited area and water storage

capacity cannot carry so much water towards its surroundings canals, lakes through its river.

As a result, flood occurs during the monsoon. Therefore, it can be explained that, the

elimination of local water storages areas by land filling is one of the major causes of storm

water flooding and water logging in many locations. During flood, the suffering of the rural

poor and middle class society knows no bounds.





Loss of natural soil nutrients

All the soil of the area of Daulatpur upazila is formed in recent sub-recent alluvium

sediments. Most of the soils are seasonally flooded, have silty to clayey textures and

moderate to low contents of organic matter. As the study area is flooded during every flood,

and river bank erosion is more here for that reason most of the water bodies that are present is

decreasing day by day and the water holding capacity of soil becoming diminish. As a result

of this organic matter of soil are losing day by day.

Degradation of water quality

Over population is putting serious pressure on freshwater supply. One important factor

affecting freshwater availability is associated with socioeconomic development, and another

factor is the general lack of sanitation and waste treatment facilities in high-population areas.

The amount of available freshwater is closely linked to the quality of the water, which may

limit its use. Fresh water of wetlands is one of the important sources for them to get water for

their daily needs. A large number of people in different villages of the study area used water

in different purpose, such as, bathing, washing, clothes, and cooking. However, with the

increasing of filled up land, wetlands changed into built up area and the people are deprived

on to get fresh water day by day their daily use.

Impact on human sectors

Change in cropping patterns and amount of production

A large number of cropping patterns are generally practiced in the study area, depending on

the crop production environment, which is greatly influenced by land type, soil texture,

flooding regimes, rainfall (amount and distribution), and resource base of the farmers. Crops

are grown in a particular order to utilize the nutrients in the soil, and to prevent the build-up

insects and fungal pests. The study area cropping patterns and amount of production has been

changed due to wetland transformation. The List of agricultural crops in the study area is

listed in the table-6.

Table 6: List of agricultural crops cultivated in the study area

Cereal crop

Sl.

No


1990 2004

1 Aus Oryza sativa VC E Food

2 Aman Oryza sativa VC VC Food

3 Boro Oryza sativa VC C Food

4 Irri Oryza sativa C VC Food

5 Gom Triticum aestivum VC C Food

6 Bhutta Zea mays VC R Food

7 Cheena Panicum miliaceum VC E Food

8 Kaon Setaria italica VC E Food

Pulse crop

1 Chola Cicer arietinum VC E Food

2 Mushur Lens culinaris VC C Food

3 Mugh Vigna mungo VC R Food

4 Mashkolai Vigna radiata VC VC Food

5 Kheshari Lathyrus sativus VC VC Food





6 Motor Vigna unguiculata VC C Food

Oilseed crop

1 BadamiSorisha Brassica campestris VC R Food

2 HoludhSorisha Brassica campestris C E Food

3 Raisharisha Brassica napus VC ED Food

4 Surjumukhi Helianthus annuus VC R Food

5 Til Sesamum indicum VC VC Food

6 Cheenabadam Arachis hypogea VC C Food

7 Tissi Linum usitatissimum VC ED Food

Vegetable Crop

1 Mula Raphanus sativus VC C Food

2 Khira Cucumis anguina VC ED Food

3 Jhingga Luffa acutagula C R Food

4 Dhundul Luffa cylindrica VC C Food

5 Ucche/Karala Momordica charantia VC C Food

6 Kakrol Momordica

cochinchinensis

C R Food

7 Patal Trichosanthes dioica VC R Food

8 Chichingga Trichosanthes anguina VC R Food

9 Alu Solanum tuberosum VC C Food

10 Begoon Solanum melongena VC C Food

11 Tomato Lycopersicon

esculentum

VC C Food

Spices and condiment

1 Morich Capsicum annum VC C Food

2 Jhal marich Capsicum species VC C Food

3 Holudh Curcuma longa C R Food

4 Ada Zingiber officinal VC R Food

5 Piyaj Allium cepa VC C Food

6 Roshun Allium sativum VC R Food

7 Dhaniya Coriandrum sativum VC R Food

Fibre crops

1 Tosa pat Corchorus olitorius C E Household

2 Sada Pat Corchorus capsularis VC R Household

3 Mesta pat Hibiscus sabdariffa C ED Household

4 Chan pat Crotolaria juncea C E Household

Sugar crop

1 Kushul/Aakh Saccharum officinarum VC R Food

2 Khajur Phoenix sylvestris C ED Food


[Code: Status: VC= Very Common; C= Common; R= Rare, ED=Endangered; E=Locally

Extinct]

Table-6 shows that there are seven variety of crops has already locally extinct from the study

area and other five crops are in endangered which is the direct effect of wetland

transformations. Rice has been broadly divided into three classes’ aman boro, and aush in the

study area. Table-7 shows the change in major crop production in amount in different study.

Table 7: Change in major crop production different year (kg/Acre)





SL.

No

Name of the crop Amount of Production (kg/Acre)

in different year

1990 2004

1 Aus 1121 0

2 Aman 1682 1121

3 Boro 1121 785

4 Irri 3364 3700

5 Gom (Wheat) 1345 1009

6 Mushur (Lentil) 561 336

7 Mashkalai (Black gram) 673 448

8 Kheshari (Chickling vetch) 897 561

9 Sharisha (Mustard) 897 673

10 Cheena badam (Groundnut) 897 785

11 Til (Sesame) 561 448

12 Alu (Potato) 2242 1682

13 Sada Pat (White Jute) 897 561

14 Kushul/Aakh (Sugarcane) 1682 1009


The above table shows that production of major crops in the study area has been changed a

lot. Compared with the two study period we can see that the amount of production in 1990

was much higher than 2004. Only IRRI rice production is increased but the production of all

other crops has been decreased. The causes of this are included riverbank erosion and

sedimentation and most important factor is wetland transformation.

Change in occupation

Water transportation is cheaper, safer, and environment-friendly, and it is play a significant

role in the economic life of the people related to water transportation. Most areas remain

under water for two to five months a year and water remains near about all the years around

in the most of the perennial water bodies particularly in the river. That is why a number of

people have been engaged in water transportation sector. Fishing is another important activity

in wetlands. A big number of people were engaged in fishing. Other occupations related to

wetlands were ferryman, day labour in boat, seasonal businessman, seasonal potter etc.

Table 8: Household in dwelling unit by main source of income

Sl.

No.

Source of income Income percentage (%)

in different year

1991 2001

1 Cultivator/share cropper, livestock, forestry 44.54 52.27

2 Fishery - 1.56

3 Agricultural labour 26.17 20.03

4 Non-agricultural labour 2.91 3.42

5 Handloom 0.41 0.26

6 Business 9.70 9.58

7 Construction 1.04 0.98

8 Transport 1.39 1.53

9 Service 4.61 5.87

10 Industry - 0.51

11 Hawcker - 0.34

12 Religious - 0.16

13 Rent - 0.024





14 Remittance - 0.38

15 Others 9.23 4.66

Source: Population Census 1991 and 2001; community series: Manikganj

From the table-8 it can be seen that most of the people occupations have been changed at

present time. Pisciculture was a main source of income to about 0.06% population of the

study area in 1991 but in 2001, this source of income was not found in the census report.

Another important part of the analysis is in 1991 agricultural labour was 26.17% households’

main income source but in 2001 it decreased to 20.03%. Those people have changed their

occupation and diverted into another occupation.

Reduces transportation facilities

Once upon a time, there was a great possibility to develop water based transport facility in

and around the Daulatpur upazila because three major rivers Jamuna, Dhaleswari and

Ichamati were surrounded by the Daulatpur upazila. Besides those rivers, there are a large

number of canals, lake in the Daulatpur upazila. Therefore, there was a possibility to develop

water transport facility in the study area. However, the possibility has been reduced, because

with the increasing of study area population at a very high rate. Most of the canals and

depression have been filled up to meet the residential and other infrastructural facilities of the

study area. As a result, the people of the study area are deprived from water base transport

facilities which area comparatively low cost.

4. Conclusion

The study area is a low-lying flood prone area where changing pattern of wetlands over the

years is a very common issue. Most of the wetlands of that area are filled with sand, silt and

clay due to flood and riverbank erosion. Expansion of human settlements is also responsible for

wetlands reduction. This research has attempted to detect the change of wetland areal extent of

Daulatpur upazila using remote sensing approach and found that within fifteen years, nearly

600 acres wetlands has been reduced within this period of time. The degradation of wetlands

created several problems on livelihood and ecosystems. People’s livelihood and the national

economy are dependent on the continued productivity of soil, water, forest, and fisheries.

Without taking enthusiastic action to prevent further degradation and reduction of natural

resources, national economic development will not be continued and sustained. Wetlands as

special biotic reserves should be managed along with research, monitoring and evaluation and

planning for their sustainable development. So it is very important to conserve the wetlands of

study area for our balance environment. Considering local demand with social, economic and

physical factors we have to take environmental friendly action in case of wetlands

management. Necessary steps and development strategies should be taken to define vulnerable

sites by geographical distribution of wetlands for sustainable wetlands conservation by

government and non-government authorities in priority basis.

5. References

1. Akonda, A. W., (1989). Wetlands of Bangladesh. In: Scott, D.A., (eds.). A dictionary

of Asian wetlands. Gland, Switzerland: IUCN-The world conservation union.

2. Banglapedia, (2007), National Encyclopedia of Bangladesh, Asiatic society of

Bangladesh, Dhaka.





3. Bangladesh Center of Advance Studies (BCAS), 620 Road 10/A (New), Dhanmondi,

Dhaka – 1209, Bangladesh.

4. Bangladesh Space Research and Remote Sensing Organization (SPARRSO),

Agargaon, Sher-E-Bangla Nagar, Dhaka-1207.

5. BBS, (1991), Population Census Report, zila series: Manikganj. Dhaka: Bureau of

statistics, Ministry of planning, GOB.

6. BBS, (2001), Population Census Report, zila series: Manikganj. Dhaka: Bureau of

statistics, Ministry of planning, GOB.

7. Islam, A. K. M. N., (1993), Ecological characteristics of fresh water Wetland. In:

Nishat, A. et. al. (Eds.), Fresh water wetlands in Bangladesh- issues and approaches

for management. Dhaka: IUCN-The world conservation union.

8. Keddy, P. A., (2000), Wetland Ecology: Principles and conservation. Cambridge

University Press, UK, p 614.

9. Mitsch, W. J., and Gosselink, J. G., (1993), Wetlands (2nd

edition). New York: Van

Nostrand Reinhold Co.

10. Rahman, A. K. A., (1993), Wetlands and fisheries. In: Nishat, A., Hussain, Z., Roy,

K.M., Karim, A., (Eds.), Fresh water wetlands in Bangladesh-issues and approaches

for management. IUCN, The World Conservation Union, pp 199-212.

11. Reza, R., (1993), Wetland Policies, Rules, and Regulations in Bangladesh. In: Nishat,

A., et. al. (Eds.), Fresh Water Wetlands in Bangladesh- Issues and approaches for

Management, Dhaka: IUCN-The World Conservation Union.

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