SBL GSS Division

Groundwater Regime Monitoring and its Significance in Groundwater Management

By

Venugopalan Nair

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Outline

1. Outline2. Introduction3. Why Groundwater monitoring is

required4. Groundwater Regime monitoring5. Groundwater monitoring cycle6. Period of measurement7. Establishment of network stations8. Base line data collection9. Groundwater level data collection10.Analysis of water level data11.Groundwater scenario of India12.Groundwater quality monitoring13.Challenges in monitoring14.Groundwater management through

monitoring

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Self Introduction

Name: Venugopalan NairEducation: M.Sc. (Applied Geology), Barkatullah University, Bhopal, IndiaM.Tech (Remote Sensing), Bharathidasan University, Trichy, IndiaM.Tech (Hydrology), IIT, Roorkee, India

Experience: 15 Years + in GISNational Geophysical Research InstituteGB Pant Institute of Himalayan Environment and DevelopmentDefense Terrain Research LabCentral Groundwater BoardRMSISBL

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Why Groundwater Regime Monitoring

Ground Water is extensive, concealed and inaccessible resource and its changes in quantity and quality are through slow process. Quick monitoring is not possible Require long term monitoring and its analysis and interpretation Is an indicative of hydrologic stresses undergone by aquifer which is having impacts on Groundwater recharge, storage and discharge Will help in design, implement and monitor the effectiveness of Groundwater management, protection and conservation program. Intervals depends on purpose

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Groundwater Regime Monitoring

Definition: Water level measurements from a network of observation wells.

It is a collection of data, generally at set locations and depths and a at regular time intervals in order to provide information which may be used to determine the state of groundwater both in quantitative and qualitative sense, provide the basis for detecting trends in space and time, and enable the establishment of cause-effect relationships.

Objective: Is to record information on Groundwater level and quality through representative sampling in space and time

Time period: January, April/May, August, November (samples on April/May)

Process involved: Establishment of monitoring stations Base line data collection Data collection Data storage and arrangements Statistical and spatial analysis Interpretation

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Period of Measurement

January - 1st to 10th of the month- represents the recession stage of water level

April\May - 20th to 30th of the month - represents water level of Pre-monsoon period

August - 20th to 30th of the month - represents peak monsoon water level

November - 1st to 10th of the month- represents water level of Post-monsoon period

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Groundwater Monitoring Cycle

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Establishment of network stations

A groundwater monitoring network is a system of dedicated Groundwater monitoring wells in a geo hydrological unit at which Groundwater levels and water quality are measured at pre-determined frequency.

Criteria:

It should be representative for hydro geological set up There should be optimum number of stations based on management criteria There should not be any immediate abstraction or drawdown effect Station should be accessible Station should be permanent and is representative of local area There should be replacement possibilities Due consideration of hydrological process in the unit

Monitoring stations can be

A key hole to aquifer An abstraction well (tube well, bore well, or dug well) Observation well Piezometers

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Baseline data collection

Done at the time of development of a well A static water level will be recorded as m bgl Estimate altitude of the location with respect to mean sea level in a msl A well log will also be prepared Water samples will be collected for individual aquifers These analysis results will be recorded and retained for further comparison

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Groundwater level data collection

Non-flowing wellsSteel tape and chalk Electric tapePressure transducers Acoustic probeUltrasonic Floats Poppers Air Lines

Flowing wells Transducers Manometer/pressure gage

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Analysis of Water level data

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Groundwater Level Scenario of India

Total number of NHNS: 12225

North of Ganges 2-5m bglNorth Western India 10-40m bglDelhi, parts of Rajasthan >40m bglEast and West <10m bglCentral India 2-5m bgl

Rice/Fall <2m 2-4m >4m

Rise in water level 46% 11% 5%

Fall in water level 28% 5% 2%

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Water Quality Monitoring

pH TDS EC Total alkalinity Ca, Mg, Na, K Carbonate, sulphate, Fluoride, bicarbonate, nitrate, Chloride Total anions, total cations Sodium absorption ratio

Categorization of water into drinking, agricultural, industrial etc

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Challenges in Groundwater Monitoring

Data loss during and after measurement Inefficient use of man power and machinery Expensive instruments and logistics No visible return of investment Difficulty in vertical variation in quantity and quality Accuracy of the data Monitoring of deeper and confined aquifers is difficult

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Groundwater Management Through Monitoring

Monitor impacts of abstraction on Groundwater system on a regional and local scale Groundwater balancing and budgeting Calibration of numeric aquifer models Determining pump usage and horse power Determining the usage of water (potable, irrigable, industrial etc) Early warning of potential threats in quantity and quality of Groundwater Monitoring and managing of salt water intrusions Monitoring of health hazards To establish legal liabilities for pollution incidents and quantity issues Monitoring droughts and floods Monitoring water logging

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Groundwater Management – A solution

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Groundwater Management – Where GIS connects the dots

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Carnival Infopark - Phase IIKakkanad, Cochin, India – 682030