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GROUNDWATER MODELLING FOR SUSTAINABLE DEVELOPMENT
USING GIS TECHNIQUES
Novaline Jacob, J. Saibaba and P.V.S.P. Prasada Raju
Advanced Data Processing Research Institute,'Dept, of Space, Govt, of India
203, Akbar Road, Tarbund, Manovikasnagar Post, Secunderabad - 500 009 (India)
ABSTRACT
The groundwater resource is often exhausted due to, increasing groundwater consumption and/or decreasing recharge of
groundwater. The groundwater occurrence in a landscape can only be recharged by broader infiltration and, mainly by infiltrating
precipitation. Therefore, in the long-term view, groundwater consumption must be adjusted to this input, if the groundwater balance
is intended to be preserved or restored. For this, a regional landscape groundwater management is needed with the aim to preserve
the long term groundwater use by maintaining a suitable well-poised landscape water balance and to protect the groundwater
quality by avoiding deposits of critical loads. Certain issues that should be handled by a Groundwater Management System are
discussed in this paper. In this paper, we present procedures for assessing groundwater quantity and quality and also measures for
improving the groundwater quality and quantity.
1.0 INTRODUCTION
Water, though being a renewable natural resource
is being exploited to such an extent that depletion rarely
balances replenishment causing danger for sustainable
development. This situation is characterised by two
effects :
(i) Increasing groundwater consumption: Especially
very densely populated or highly industralised
urban areas are managing the water requirements
by means of groundwater resources of their close
and remote surrounding. Groundwater
consumption in agriculture and horticulture is also
increasing due to irrigation.
(ii) Decreasing recharge of groundwater: A higher
level of surface sealing preventing infiltration into
the underground can be found not only in urban
areas but also in agricultural areas. By intensified
agricultural practices, plant production generates
more biomass and crop yield. But for every unit of
yield and biomass, the plant has to transpirate
additional soil water. Therefore, higher intensity in
farming is related to higher water consumption by
the process of évapotranspiration. Also, a larger
portion of precipitation is drained off by drains.
By these reasons, the groundwater balance resource
is often exhausted in the long run. The effect is lowering
of groundwater level.
Numerous instances of subsurface contamination
and pollution of groundwater resources have arisen from
improper storage, use and handling of organic
compounds such as chlorinated solvents, creosotes etc.
The characterization and remediation of hazardous waste
sites that are the sources of these contaminants are issues
of major concern. With the intensification in agriculture
it can also be observed, that the leaching of nitrate is
increasingly exceeding the critical load of groundwater.
This is the reason why groundwater quality is actually a
prevailing aspect in groundwater protection.
In view of these effects on groundwater quality and
quantity, many water supply companies have started to
exploit the deep groundwater sheets, although the long
term yield of this kind of aquifer layers is quite
unknown.
Ultimately, the groundwater occurrence in a
landscape can only be recharged by broader infiltration
and, mainly by infiltrating precipitation. Therefore, in
the long-term view, groundwater consumption must be
adjusted to this input, if the groundwater balance is
intended to be preserved or restored. For this, a regional
landscape groundwater management (Selige et a/., 1994)
is needed with the aims :
(i) to preserve the long-term groundwater use by
maintaining a suitable well-poised landscape water
balance.
(ii) to protect the groundwater quality by avoiding
deposits of critical loads.
To manage groundwater as a long-term available
and balanced property of landscape, we have to take into
consideration the influences on landscape water balance.
