Irrigation water management studies in Agniyar river basin

Abstract

The present study is aimed to establish information on the groundwater potential zone and Water balance in Agniyar river basin, Tamil Nadu, The total geographical area of basin is 4663.15 Sq.km. (It falls in the Survey of India degree sheets 58 J , 58 N and 58 O on 1:250,000 scale). The thematic maps such as geology, geomorphology, soil hydrological group, land use / land cover and drainage map were prepared for the study area using Landsat 8 images. The Digital Elevation Model (DEM) has been generated from the Shuttle Radar Topography Mission (SRTM) data with 30 m resolution and contour lines from toposheets and obtained the slope (%) of the study area. The information about groundwater potential zones of the study area were developed by overlaying all the thematic maps in terms of weighted overlay methods using the spatial analysis tool in Arc GIS 10.3. Ranking has been given for each individual parameter of each thematic map and weights were assigned according to the influence over such as soil -12%, geomorphology - 35%, geology - 20%, land use / land cover - 8%, slope - 2%, lineament - 8% and drainage - 15% and the resulting maps presents the groundwater potential zones in terms of Good (602.48 Sq.km), Moderate (353.27 Sq.km) and Poor zones (44.25 Sq.km) respectively. The result depicts the groundwater potential zones in the study area and found to be helpful in better planning and management of groundwater resources. Sustainable water management in a river basin requires knowledge of the water availability and water requirements of the basin in the present and future for various purposes. The complexity of the water system in the region can be understood by calculating the regional water balance in a distributed scale considering the factors that affect it. newline