Effects of Subbasin Scale with Distributed Runoff Model

Abstract

Recently, weather radar and geographic information systems are available to forecast the runoff. It is important to establish the distributed runoff models to make effective use of these spatially variable informations. This paper discusses effects of subbasin scale with distributed runoff models. For this purpose, it is approached that (1) the formula of transmitted channel network geometry under changing map scale in a catchment and the relationship between the properties of subbasin topography and map scales are investigated analytically;(2) the distributed runoff model based on channel network properties is derived. Consequently, the relationship between peak discharge and subbasin scale is derived, and an optimum subbasin scale for hydrologic response is shown.