Estimation of Water Balance Components in the Dhasan river basin

The present work involves the evaluation of water balance components with the popular Thornthwaite and Mather method (1957) for the Dhasan basin in Sagar district, Madhya Pradesh. The daily rainfall and temperature data pertaining to the study area are used in estimation of various components of water balance like water surplus, water deficit, runoff, etc. The study reveals that on normal basis, the basin has an annual water requirement of 1770 mm whereas the rainfall is 1149 mm and actual evapotranspiration is 821 mm. The analysis has revealed a water surplus of 327 mm during monsoon months of July, August and September whereas the water deficit of 948 mm during the remaining period. The water deficit actually starts from the month of October, i.e. soon after the withdrawal of monsoon and generally increases with onset of the summer season. Since the wheat is the major crop being sown during rabi season in the catchment area, irrigation has to be planned accordingly for the crops. Moreover, since the annual water deficit is much more than annual water surplus, the basin may be considered to be drought prone.