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The main factors to be included in the view of 
groundwater management are climate, soil and geology, 
relief and vegetation. A landscape-ecological oriented 
management has to base on these factors. But the course 
of management action cannot influence the climate and 
the relief, of course. Also the soil attributes cannot be 
changed in an economical way. Mainly landuse can be 
adjusted by the way of planning the kind and intensity of 
farming and foresting, plant rotation, nutrient supply etc. 
(Selige et al., 1994). 
Certain issues that should be handled by a 
Sustainable Groundwater Management System are listed 
in the flow chart (Figure 1). Modelling can be done in a 
Geographic Information System (G1S) by clubing the 
hydrologic models with the GRID-based environment 
supported by GIS. 
2.0 DATA BASE AND STRUCTURE 
• The study area can be converted into a grid, with 
grid cell of suitable resolution. 
• Since most of the groundwater related data would 
be available from pumping wells/bore hole logs 
they would be point information, which could be 
interpolated to get spatial data (i.e.) each grid cell 
would have valid data without any gaps. 
• Point data could be water level, weathered zone 
thickness, saturated zone thickness, yield in the 
wells, rainfall at various rain gauge stations, 
porosity of aquifer material, Transmissivity (T) 
and Storage co-efficient (S) depending on the 
type of porous media from the pumping test data 
etc. 
• Bore hole and geophysical sounding data can be 
interpolated to prepare aquifer basement map. 
• In order to assess the groundwater prospects by 
qualitative modelling, data on geomorphology, 
geological structures, lineaments would also be 
required in addition to weathered zone thickness, 
saturated zone thickness and yield in the wells. 
Lineaments being line data have to be converted 
into a spatial data by finding the lineament 
density on a coarse grid say, 1 kmx 1 km. 
• In order to assess the suitability of groundwater 
quality for irrigation, drinking or industrial 
purpose, Electrical Conductivity (EC), pH, 
Sodium Absorption Ratio (SAR) data etc., have to 
be collected from the monitoring wells and 
interpolated to get spatial data. 
3.0 MODELLING FOR GROUNDWATER 
QUANTITY 
3.1 Qualitative Modelling for Assessing 
Groundwater Prospects 
Groundwater prospects can be assessed in GIS, by 
combining various data layers on geomorphology, 
lineament density, geological structures, weathered zone 
thickness, saturated zone thickness, yield in the wells 
etc., by assigning appropriate weightages for the 
parameters and for the classes within these parameters 
(Novaline et al., 1993). Groundwater prospects would be 
finally categorised into excellent, good, moderate and 
poor classes. 
3.2 Quantitative Modelling for Assessing 
Groundwater Quantity 
Long-term rainfall data can be used to find out how 
much of precipitation reaches groundwater reservoir 
after losses at various stages like interception, run-off, 
evaporation, transpiration etc., to compute monthly 
recharges. One can determine the safe yield (i.e.) the 
amount of water that can be withdrawn from an aquifer 
without producing adverse result and can give safe 
monthly extractions. 
One way of assessing groundwater extraction 
potential is by a standard technique in statistical 
methodology (Sharma, 1987). It is found by analysis of 
water table data that ôd (yearly fluctuation of depth to 
ground water table from the ground surface) can be 
expressed as a linear function of R (mean rainfall) and V 
(water pumped from tube wells and open wells) by the 
following relationship : 
ôd = a + bR + cV 
a, b, and c are constants 
If the limiting value of ôd be taken as zero, and 
assign R the normal value of the annual rainfall, the 
corresponding values of V may be considered to be the 
limiting value of pumpage upto which there will not be 
any depletion of the groundwater table. This analysis can 
also be done in GIS. 
3.3 Supply-Demand Analysis 
Supply-Demand analysis can be performed in GIS 
to see if the recharge and consumption are balanced. 
One can group the grid cells into cells having equal 
recharge and extraction, cells having over exploitation 
and cells with no recharge with the help of monthly 
recharge, extraction and safe yield values.