Insinuation of spatial database for realistic groundwater assessment in Indian context

摘要

AbstractIndia is an agricultural-based country in which groundwater is utilized on a large scale for irrigation. Groundwater resources are indiscriminately exploited causing problems of depletion of water tables. Under this situation, an accurate estimation of groundwater resources in such regions, particularly the semi-arid regions, becomes imperative. In India, various line departments engaged in the groundwater development activities carry out assessment of groundwater potential at periodic intervals. Such programs, many times, result into over/under-estimation of groundwater resources due to non-consideration of spatial database reflecting the actual terrain conditions. Hence, the groundwater development programs in such regions could not be planned precisely. To overcome this situation, an attempt was made to assess the groundwater recharge and withdrawal affecting parameters in a watershed falling under Nagpur district of Central India through spatial database generated by remote sensing technique. For this study, the groundwater resources of the study area were evaluated on the basis of GEC norm, which is a general practice in India, and also using spatial database controlling on factors like geology, geomorphology, land use/land cover, and hydrology, etc. The comparison in between groundwater resources of the GEC norms and the approach through spatial database depicts a difference in recharge, recharge by return flow, worthy area, and withdrawal factors, etc. In this present case, the groundwater estimation based on application of GEC norms indicated an additional scope of construction of new dug wells. However, the estimation carried out using spatial database indicates the over-developed nature of watershed leaving no scope for future development. Similar situations are expected in many watersheds elsewhere in the country. Therefore, there exists a need to revise the conventional groundwater assessment methodology by involving the spatial database, which will help in implementation of groundwater development programs in the most effective and sustainable manner.