Groundwater Recharge Estimation using Empirical Methods and Water Table Fluctuation: a Case Study of Chanal and Hirehalla Watershed, Gadag District, Karnataka, India

One of the most precious natural resources is groundwater, which promotes ecological diversity, human health, and economic growth. For the sustainable management of groundwater resources, knowledge about groundwater recharge is crucial. Natural ground water recharge is the total volume of water that will eventually reach the water table. The rate and length of the rainfall, the conditions at the upper boundary afterward, the antecedent soil moisture conditions, the depth of the water table, and the type of soil all affect how much recharge occurs. In hydrology and hydrogeology, evaluating groundwater recharge from precipitation is a key component. Using empirical methods and the water table fluctuation method, an attempt was made in this paper to estimate groundwater recharge in the Chanal and Hirehalla watershed, Gadag District, Karnataka. Data on rainfall were gathered for the years 2000 to 2020. The findings demonstrated that, for the study area, the average groundwater recharge of six empirical methods and the water table fluctuation method varied by 5.22 to 196.33 mm annually and 4.62 to 103.07 mcm/yr, respectively. It is discovered that comparing different approaches is helpful in identifying the range of conceivable recharge rates as well as highlighting the estimates' uncertainty.