Geomorphological Mapping for Identification of Ground Water Potential Zones in Hard Rock Areas Using Geo-spatial Information – A Case Study in Malur Taluk, Kolar District, Karnataka, India

摘要

The search for new groundwater resources is essential to sustained economic development in aridenvironment. The study area is part of Ponnaiyar river basin falling between N latitude of 12°48’24” to13°07’06’ and E longitude of 77°50’30” to 78°08’15” falls in Survey of India toposheets 57 G/16, 57 H/13, 57K/4 and 57 L/1 covering an area of 645 km 2 in Kolar District, which is highly drought prone in KarnatakaState, India. In the present paper, by a methodological approach based on remote sensing and GIS, drainageand hydrogeomorphological maps were prepared using the IRS-1 C & 1 D LISS-III and PAN merged satellitedata and geomorphic units. Denudational hill, residual hill, inselberg, pediment inselberg complex, pediment,shallow weathered pediplain, moderately weathered pediplain and valley fill shallow were identified. The areais characterised by undulating terrain interspersed by low ranges of rocky hills. The elevation ranges from860 m to 1127 m above MSL. The mean annual rainfall of Malur is 722.0mm. The River Dhakshina Pinakiniand Markarda Halla drain the area. The streams exhibit dendritic to sub dendritic type of drainage patternand comprise of granite and gneissic rock formations of Achaean age. On the basis of different geomorphicunits, four categories of groundwater potential zones were delineated as (i) very good to good (ii) good tomoderate (iii) moderate to poor, and (iv) poor to very poor.