Structural Universality of the Distributed Hydrological Model for Small- and Medium-Scale Basins with Different Topographies

Abstract

Developing a distributed hydrological model that is applicable to a variety of topographies is a substantial challenge to the hydrological modeler. The primary objective of this study was to develop a distributed hydrological model that has a universal structure and an adjustable core module for small- and medium-scale basins under various topographical and hydrogeological conditions. By analyzing structural characteristics of soil vertical profile and general process of rainfall-runoff calculation under the different topographical conditions, a distributed hydrological model with universal structure was devised by combining the kinematic wave theory with the geographic information system (GIS)–based data on the topographical and hydrogeological conditions of target basins. Model validations were conducted through numerical simulation of the observed flow-discharge for the following three basins with varied topography: (1) the Liudaogou Basin, which is located in the region of the northern Loess Plateau and is abundant in hills and gullies; (2) the Alun River Basin, which flows through eastern Inner Mongolia and the western Heilongjiang Province; and (3) the Bukuro River Basin, which is located in Japan. The results indicated that acceptable simulation results for the rainfall-runoff process were achieved under varying topographical and hydrogeological conditions in each basin and that the calculation accuracy was within the allowable range according to the error criterion (error < 0.03). The model exhibited relatively high efficiency, and the Nash-Sutcliffe efficiency (NSE) was more than 0.90. Structural universality and core module adjustability of the model are discussed and analyzed for applicability under various topographical and hydrogeological conditions. The results are expected to provide a methodological reference for further studies on the distributed hydrological model for small- and medium-scale basins with varied topographical and hydrogeological conditions.