SIMULATION OF HYDROLOGICAL CYCLE IN AN URBANIZED CATCHMENT AND EFFECT EVALUATION OF INFILTRATION FACILITIES

A distributed hydrological model is applied to simulate water balance in the Ebi river catchment (27km2) with a grid size of 50m and a time step of 1 hour. The simulation of 5 years from 1992 to 1996 is performed. The model is verified through comparisons of simulated river discharges and groundwater levels with the observed values. The comparison of water balance at present (1993) with that in future (2035) is also conducted and it shows the impact of urbanization. To conserve hydrological cycle in the catchment implementation of infiltration facilities is thought to be highly required. The effect of infiltration trench is studied. It is found that the hydrological cycle can be improved at same level or even better in future than now if infiltration trench is implemented to infiltrate drainage from urban canopies.