Geology Reference
In-Depth Information
The map of water balance (Fig. 5) shows that negative balance areas only
correspond to pumping areas due to the fact that pumping flows and return
flows are respectively the main negative and positive components of the
balance. In spite of the fact that they represent only 25% of the 1324 cells,
the whole balance is negative.
CONCLUSIONS
The annual water balance of Maheshwaram watershed was calculated from
June 2001 to June 2002. The global balance on the whole basin is a little bit
negative, inducing a depletion of 1.18 metres for the water table in spite of
the occurrence of a normal monsoon. The use of a Geographical Information
System allows presenting a spatial budget.
The applied method gives very consistent results. It necessitates a good
knowledge of pre- and post-monsoon groundwater levels. Thus, a network
of observation of one hundred observation wells is necessary on this basin
of 53 km
2
with monitoring twice a year. The accurate evaluation of pumping
is also necessary for the determination of the balance and of the specific
yield.
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