Runoff Simulation by SWAT Model Using High-Resolution Gridded Precipitation in the Upper Heihe River Basin, Northeastern Tibetan Plateau

Abstract

Abstract:The scarcity and uneven distribution of precipitation stations in the inland river basins of the Northeastern Tibetan Plateau restrict the application of the distributed hydrological model and spatial analysis of water balance component characteristics. This study used the upper Heihe River Basin as a case study, and daily gridded precipitation data with 3 km resolution based on the spatial interpolation of gauged stations and a regional climate model were used to construct a soil and water assessment tool (SWAT) model. The aim was to validate the precision of high-resolution gridded precipitation for hydrological simulation in data-scarce regions; a scale transformation method was proposed by building virtual stations and calculating the lapse rate to overcome the defects of the SWAT model using traditional precipitation station data. The gridded precipitation was upscaled from the grid to the sub-basin scale to accurately represent sub-basin precipitation input data. A satisfactory runoff simulation was achieved, and the spatial variability of water balance components was analysed. Results show that the precipitation lapse rate ranges from 40 mm/km to 235 mm/km and decreases from the southeastern to the northwestern areas. The SWAT model achieves monthly runoff simulation compared with gauged runoff from 2000 to 2014; the determination coefficients are higher than 0.71, the Nash-Sutcliffe efficiencies are higher than 0.76, and the percentage bias is controlled within ±15%. Meadow and sparse vegetation are the major water yield landscapes, and the elevation band from 3500 m to 4500 m is the major water yield area. Precipitation and evapotranspiration present a slightly increasing trend, whereas water yield and soil water content present a slightly decreasing trend. This finding indicates that the high-resolution gridded precipitation data fully depict its spatial heterogeneity, and scale transformation significantly promotes the application of the distributed hydrological model in inland river basins. The spatial variability of water balance components can be quantified to provide references for the integrated assessment and management of basin water resources in data-scarce regions.

Future Runoff Variation and Flood Disaster Prediction of the Yellow River Basin Based on CA-Markov and SWAT

“…If the absolute value of RE between runoff simulation and observation values is less than 20%, NS is greater than 0.6 and R 2 is greater than 0.6, it is considered that the established SWAT model can be applied to simulate the runoff of the study area [43][44][45][46].…”

Application of Meteorological Element Combination-Driven SWAT Model based on Meteorological Datasets in Alpine catchment: A case study in the Yellow River Source Region (China)

“…In this study, virtual weather stations were constructed for each sub-basin that adopts the mean weather element of the site within each sub-basin; all sites data could be utilized to build virtual stations on a sub-basin scale. Detail information on the establishment of Virtual weather station can refer to Ruan et al (2017)…”

Long-Term Variation of Runoff Coefficient during Dry and Wet Seasons Due to Climate Change

“…The Soil and Water Assessment Tool (SWAT) model was developed firstly in the early 1990s by the United States Department of Agriculture, Agricultural Research Service (USDA-ARS). SWAT is a continuous-time, semi-distributed, and process-based model operating on a daily time step at the basin scale, and is well-known for its wide-application capabilities in simulating hydrological processes in large catchments using the subbasin concept under different conditions and scenarios in a long-term period [35,36]. Each catchment is divided into hydrologic response units (HRUs), integrating unique land cover/land use, soil type, and slope [37].…”