Prioritization of sub-watersheds of the Kanakapura Watershed in the Arkavathi River Basin, Karnataka, India- using Remote sensing and GIS

Abstract

Prioritization of sub-watersheds is a crucial aspect of watershed management as it may not be possible to execute development programs at a time for entire watersheds in a basin owing to the paucity of financial resources. The present study attempts to prioritize sub-watersheds in the Kanakapura watershed, in Ramanagara district, Karnataka, based on the multi-criteria ranking method. This process involves extraction and determination of various parameters such as rainfall, lithology, drainage density, slope, lineament, hydro geomorphology, land-use, and land-cover, using information from rain gauges, topographical sheets, and satellite imagery in Geographic Information System (GIS) platform. Kanakapura watershed is subdivided into nine sub-watersheds, namely, Bannimukudlu, Bennagodu, Doddaalahalli, Gadasahalli, Horalagallu, Kodihalli, Madarahalli, Maralebbekupe, and Mudagod. Priorities indexing of each of the parameters was done, based on their impact significance, and overlay analysis was performed to identify critical sub-watersheds. Some of the strategies proposed for effective conservation and management of water resources are the construction of a check dam, implementation of water harvesting methods, identification of artificial recharge sites. The results of the study show that priority needs to be given to the Bannimukudlu and Kodihalli sub-watersheds followed by remaining sub-watersheds to regulate surface water flow thereby improving water table level.

Keywords

• sub-watershed prioritization
• remote sensing
• gis
• thematic map
• hydrogeomorphic units
• weighted index overlay analysis