APPLICABILITY OF AN IMPROVED WATER AND ENERGY TRANSFER PROCESSES MODEL ON RAPID RAINFALL-RUNOFF EVENTS OF TOKYO URBAN WATERSHEDS

Abstract

This paper highlights the application of Water and Energy Transfer Processes (WEP) Model to two highly urbanized watersheds within Tokyo, Japan; Nomikawa and Meguro watershed. Major model improvements include refinement of time-resolution input rainfall data from 1 hr. to 10 min. intervals, and addition of subroutine to accommodate weir/side-weir effects and rainfall input. 2007 heavy rainfall data from Tokyo AMESH were used in Nomikawa watershed simulation. 2008 heavy rainfall data from Tokyo Metropolitan Construction Bureau were also used to simulate runoffs for Meguro watershed. The improved model was validated using comparative analysis of previous and new model using simulated river discharges and actual gauge measurements. Results show the new model simulates rapid runoffs well.