SOME HYDROLOGICAL ASPECTS OF A NATURAL FOREST IN THE MID-COUNTRY INTERMEDIATE ZONE OF SRI LANKA

Abstract

Total and net rainfall were measured by rain gauges in the open and under thecanopy, records front a station 5 kill aW(~y were also used. infiltration wasmeasured by a double ring infiltrometer. Transpiration was estimated frontchanges in soil-moisture storage, as measured by the neutron probe method.Provision lms made to measure surface runoff,' but there was none; injiltrationrates were well above maximum rainfall intensity. Although some of the data arenot complete, it is concluded that the tree vegetation loses relatively smallamount of water bv interception and transpiration in the dry season, for thereason that the roots have limited access to water.