Abstract
For Higashiyama watershed the value, 1.45 mm/day, of evapo-transpiration from ground water reservoirs by riparian vegetation in summer was computed by the use of difference between the ground water depletion curve in winter (Jan. & Feb.) and that in summer (July & August). And the method to compute daily values of this water loss by riparian vegetation is presented on the basis of THORNTUWAITE'S potential evapotranspiration.