Geology Reference
In-Depth Information
Scenario 3 presents the results of a scenario where only rain harvesting
structures are built to stabilize groundwater level decline (Fig. 3). However,
about 230 hectares of tanks (or 270 dug-wells) are required. This non-
realistic scenario shows that the artificial recharge cannot be considered as
the only solution. One may question in such a semi-arid context the efficiency
of groundwater management only based on such a solution.
One may conclude that in the present situation of Maheshwaram watershed,
which is not an isolated case in the country and not an area recognized as
an extremely or under overexploited area, reasonable solutions can be found
by a package of solutions, i.e. combining changing cropping pattern, improving
the irrigation techniques, new rain harvesting structure, etc. The water levels
would be more or less maintained before getting back their original levels
at the end of the plan; therefore this would induce a sustainable solution.
CONCLUSION
The DST is mainly based on changing cropping pattern solutions: that means
trying to decrease the Real Evapo-Transpiration component of the water
budget. It enables the increase or decrease of surface area of any crop
present in the watershed. In order to avoid non-realistic scenarios, which
could not be accepted by the farmers because of profitability or cultural
issues, the DST has been designed to enable the input plan actions for
several years under various socio-economic criteria.
As we have seen in Fig. 3, which considers a 15-year action plan scenario,
decreasing the rice surface area every two years by 5%, at the same time
increasing vegetable and flower surface area by 10%, and reasonably adding
a package of solutions like the contribution of artificial recharge techniques
to groundwater, or the improvement of irrigation techniques, or even a public
awareness programme
This scenario shows that in any case the artificial recharge cannot be
considered as the only solution. Its contribution to improve the situation is
quite less than a changing cropping pattern solution. But a combination of
both solutions could seriously improve the groundwater situation. Thus the
only solution to get a sustainable groundwater management will come from
a package of solutions.
The need of the hour is to adapt the exploitation of groundwater to its
availability. Due to this, it is indispensable that policy makers be equipped
with suitable predictive tools to better guide their coming actions.
The place of the DST (Fig. 5) is between policy makers and the experts,
the experts helping them to build up realistic scenarios including the socio-
economic aspects and the policy maker's own constraints as well. The results
of simulations can be criticized, optimized or validated together, and it is
only afterwards that the authorities can launch the actions. In addition, the
package is entirely interactive and the scenarios could be built up by the
