By means of SSiB/TOPMODEL model which was the coupled model of simplified simple biosphere model(SSiB)and TOPMODEL,the sensitivity experiment of basin water balance was carried out in Suomo River basin covered by five vegetations,and the effects of vegetation on water balance were analyzed.The results showed that vegetation cover increased canopy transpiration and interception but decreased soil evaporation.The two contrary net effects determined the basin runoff affected by the hydrological effect of vegetation.For the five simulated vegetations,basin evaporation went down but basin runoff went up compared with bare land.When basin was covered by grass,total basin evaporation was highest(1.220 5 mm/d),and total basin runoff was the lowest(0.658 7 mm/d).When deciduous needle-leaf forest covered the basin,total basin evaporation was minimum(1.025 mm/d),while total basin runoff was maximum(0.854 4 mm/d).Transpiration and canopy interception reached maximum values of 0.383 and 0.489 mm/d when covering evergreen coniferous forest.For soil evaporation,it was highest with grass(0.799 mm/d)and lowest with evergreen coniferous forest(0.243 mm/d).
