Rainfall-Runoff Variability for The Upper Krishna-bhima Basin Upto Priyadarshini Jurala Dam Site

On the basis of available rainfall and discharge data of the seven sub-basins, viz. K1 to K7 (as defined by the CWC authority) of the Upper Krishna-Bhima basin up to Jurala Project site in Peninsular India, analysis has been carried out to review the rainfall trends and its spatial distribution; rainfall-discharge variability and to determine any useful relationships between the two. The basin up to Jurala Project site received 95% of the mean annual rainfall during the months of June to October. K2 sub-basin, parts of K5+K6 sub-basins which fall in the arid to semi-arid region experienced very less rainfall with high CV.

Monthly and annual runoff coefficients estimated for the six sub-basins and entire Krishna-Bhima basin are presented in polygon images of rainfall and corresponding runoff. These polygons may give useful information about the duration and magnitude of runoff, variation of runoff coefficient with time, etc. In addition, these polygons also provide a common basis for many qualitative explanations about catchment/basin response to rainfall. The runoff coefficient for the basin as a whole was estimated to be 0.04, whereas it varies for all the six sub-basins with the highest variation recorded in K2 sub-basin.