荒川流出試験地における水収支について

Abstract

This paper describes the relation between soil moisture profile and groundwater runoff in Araexperimental basin, and the quantity of interception and evapotranspiration obtained by waterbalance equation. These results are as follows:1) Observed groundwater runoff rate increases when soil moisture of 50-100 cm below theground surface comes up to the maximum capillary water content.2) The amount of interception by forest is about 3 mm.3) The maximum and constant evapotranspiration rate of 7 mm/day continues about 1.5 daysafter rain ceasing.4) Evapotranspiration rate decreases exponentially during 1.5~- 13 days after rain ceasing.5) The steady evapotranspiration rate of 1.2 mm/day appears from 13 days after rain ceasing.