Abstract
Digital elevation models (DEM) are extensively used in hydrological analysis to obtain distributed hydrological attributes and the flow direction. Demerits are consistently hindering hydrologists despite the ease of using DEM with several existing methods. A new method of assigning flow directions based on flow tendency is proposed in this paper. Iterative search of continuous pits and flats are embedded inside. This method is named as Ranked Flow Tendency (RAFT) method. A storage function method is used to simulate the water movement taking the DEM of Kamishiiba Reservoir Site (210 km2) as the case. The results are compared against the conventional D8 method and modified D8 method for flow networks. The proposed RAFT method yields better flow path and is able to trace the reservoir sites. This method shows its better ability to involve more cells at off-peak wet region in flow routing.
