Using the Climate Forecast System Reanalysis Evaluate Water Discharge and Sediment Load in Upper Yom Basin

Abstract

Using climate data to estimate runoff and sediment loads with the Soil and Water Assessment Tool (SWAT) model requires relevant multivariable climate data. The measurement data is not comprehensive and complete, especially in small watersheds. The objective of this research is to calculate the water and sediment yield in the upper Yom River basin using the SWAT model with climate data from the Climate Forecast System Reanalysis (CFSR) and rainfall data from the stations within the watershed. Calibration and verification of the runoff of the models of Y.20, Y.24, Y.31 and Y.36 in the water year 1991-2020, the PBIAS values of all 4 stations were in the range of -34.43-1.06 and -18.3-1.01, the R2 value was in the range of 0.65-0.87 and 0.59-0.86, the NSE value was in the range of 0.25-0.86 and 0.32-0.85 of the calibration and verification, respectively. As for the calibration and verification of suspended sediment at Y.20 stations during 2009-2020 and Y.24 during 1997-2020, the PBIAS values were in the range of -4.23-0.69 and -7.74-30.00, the R2 values were in the range of 0.59-0.83 and 0.59-0.83, the NSE values were in the range of 0.62-0.78 and 0.57-0.78 of the calibration and verification, respectively, which is a trustworthy value. Thus, it is shown that the application of data from CFSR is another approach, which is a suitable alternative for application to small watersheds where climate data is scarce for SWAT model as well.