Assessment of Groundwater Potential Using Water Balance Approach in Pindra Block Varanasi

Abstract

Groundwater is an important source of irrigation in rural areas. Groundwater potential of Pindra block of Varanasi district was assessed using water balance approach during monsoon (June to October) and non-monsoon (November to May) season. Its various inflow and outflow parameters of groundwater balance equation were calculated such as recharge from rainfall, canal seepage, pond seepage, field irrigation, sub-surface inflow-outflow, groundwater discharge from tubewells, evapotranspiration and groundwater storage change. The results of the study reveal that various inflow parameters i.e. recharge from rainfall, canal seepage, pond seepage, field irrigation and sub-surface inflow during monsoon season were estimated 6501.41 ha m, 417.49 ha m, 9.56 ha m 1283.02 ha m and 405.98 ha m respectively. During non-monsoon period these inflow parameters were estimated 154.01 ha m, 471.40 ha m, 3.83 ha m, 3822.61 ha m and 149.57 ha m respectively. Groundwater outflow parameters i.e. sub-surface outflow, discharge from tubewells and change in storage during monsoon season were estimated 123.35 ha m, 4587.18 ha m and 0.87 ha m. These outflow parameters during non-monsoon season were estimated 561.81 ha m, 10498.33ha m and 3.95 ha m. Average recharge coefficient was calculated 47.76%. Conducting the water balance study it was found that the declining trend of the water level due to lack of surface irrigation sources and sustained groundwater pumping.