Hydrological Studies of Artal Sub-watershed of Belagavi District, Karnataka, India

Abstract

Watershed is also a hydrological response unit and a holistic ecosystem in terms of the materials, energy and information present. The Artal sub-watershed (4d5e3b) is located in the Athani taluk of Belagavi district. It lies between 16043’50” - 16045’40” North latitudes and 75017’30” - 75023’0” East longitudes and covers an area of about 4632.04 ha. The average annual rainfall (2016 - 2021) of Artal sub-watershed was 536.0 mm. The maximum precipitation of 357.3 mm is received from June to September, 108.9 mm from October to early December and the remaining 99.8 mm is received during the rest of the year. The number of rainy days (>2.5 mm) varied from 14-24 days per year. On average, number of rainy-day events likely to produce runoff (20 to 30 mm) is about 3 to 7 rainy days per year with moderate variation across the years. The Actual Evapotranspiration (AET) over the years 2016 - 2021 in the Artal sub-watershed varied from 297.0 to 558.1 mm. During 2016 - 2021, the average annual AET (421.0 mm) was less than the average rainfall (536.0 mm). The average AET/P ratio between 2016-2021 was about 0.74 which is less than the sustainable limit of about 0.80. During 2018 and 2020, the AET/P ratio were 1.14 and 1.06, respectively, which indicates receipt of less rainfall in these years and also a possibility of groundwater being augmented to maintain crop water requirements. A maximum area of about 875 ha (18.9 %) requires graded bunding and 3657 ha (78.96 %) area requires contour bunding.