Delineation of Groundwater Potential Zones and Identification of Artificial Recharge Sites in Dharta Watershed, Udaipur, Rajasthan, Using RS & GIS

Abstract

Groundwater is a precious resource of limited extent. A systematic planning of groundwater exploitation using modern techniques is essential for the proper utilization and management of this precious but shrinking natural resource. In the present study, Geographical Information System (GIS) is used to integrate multi parametric data to generate several thematic maps, delineate groundwater potential zones and identify sites of artificial recharge in the Dharta watershed, Udaipur, Rajasthan (India). The thematic layers considered to delineate groundwater potential zones are geomorphology, recharge, geology, soil, slope, topographic elevation and transmissivity, which were prepared using conventional maps and data. All these themes and their individual features were then assigned weights according to their relative importance in groundwater occurrence and the corresponding normalized weights were obtained based on the Saaty’s analytical hierarchy process. The thematic layers were finally added using Arc GIS software to yield groundwater potential zone map of the study area. Thus, three different groundwater potential zones were identified viz., ‘good’, ‘moderate’ and ‘poor’. The area having ‘good’ groundwater potential is about 10.7 km2 which is about 19.62 per cent of the total study area. The thematic layers used in this study to determine artificial recharge zones are transmissivity, recharge, topographic elevation, soil and slope. These layers were combined using boolean logic analysis to delineate zones of suitability for artificial recharge structures. The area suitable for artificial recharge is 7.84 km2 which is 14.37 per cent of the total study area.

Podzemna voda je dragocen izvor ograničenog obima. Sistematsko planiranje korišćenja podzemne vode upotrebom savremenih tehnika je osnova pravilne upotrebe i upravljanja ovim dragocenim prirodnim resursom. U ovom istraživanju je korišćen GIS za integraciju više parametara i dobijanje nekoliko tematskih mapa potencijalnih izvora podzemne vode. Tematski slojevi su: geomorfologija, obnova, geologija, zemljište, nagib, topografska elevacija i prenosivost, koji su pripremljeni upotrebom konvencionalnih mapa i podataka. Sve ove teme i njihovi pojedini entiteti su vrednovani prema značaju za pojavu podzemne vode. Tematski slojevi su na kraju dodati Arc GIS programom u mapu potencijalnih zona podzemne vode. Tako su identifikovane tri različite zone: ‘dobra’, ‘umerena’ i ‘slaba’. Oblast u klasi ‘dobra’ ima oko 10.7 km2 što je oko 19.62% cele oblasti.