Integrated Rainwater Resource Management (iRaM) Model for Coastal South Gujarat

Abstract

The South Gujarat region has ample water availability, but, water shortage is being experienced during summer and water logging during monsoon. Also, due to large scale industrialization of south Gujarat, problems of air and water pollution have arisen which have become more complex because of over exploitation of natural resources ‘ground water’. In many areas, due to continuous pumping of sweet water, sea water ingress has taken place and bores have become defunct as the water quality deteriorated drastically, due to which many cultivable farm lands have become uncultivable and are lying as wasteland. The water quality had deteriorated to such an extent that neither it could be used for drinking purposes nor for irrigation of crops. High intensity rains occur during the monsoon allowing very little opportune time for the water to infiltrate into the aquifers. All the rainwater during monsoon directly goes as runoff ultimately reaching the sea. Also, where ponds exist, catchment areas are disappearing due to construction work and ponds no longer receive rain water. So, an attempt was made to conserve the “rain water” natural resource while evaluating the potential of raising fish in small pond through harvested rain water. The water balance study was carried out in which meteorological and hydrological parameters like rainfall, evaporation, infiltration and runoff were measured and then using the water balance equation, the recharge amount was calculated and it was compared with the estimated recharge. It was concluded from the study that the rain water harvesting in small or big ponds not only replenishes aquifers but also checks deteriorating water quality in addition to providing sweet water fish harvest for economic gain