Combined Forecasting of Streamflow in the Source Region of the Yellow River Based on Interpretable Machine Learning
The source region of the Yellow River is an important runoff-producing area of the Yellow River Basin and an essential clean ener-gy base in China.Improving the accuracy of streamflow forecasting in the source region of the Yellow River will provide significant support for the scientific allocation of water resources in the basin and the efficient production of wind and solar clean energy.This article took Tangnaihai and Maqu hydrological stations in the source region of the Yellow River as research objects.Based on the differences in streamflow compo-nents in different months,considering the changes in snow coverage and snowmelt water equivalent,a medium and long-term streamflow stag-ing combined machine learning forecasting model and its interpretable analysis framework were built.The research results show that a)the streamflow forecasting period within the year can be divided into a snowmelt-affected period(March to June)and a non-snowmelt-dominated period(mainly precipitation and groundwater recharge)(July to February of the following year);b)Compared with the traditional non-stag-ing model,the Nash efficiency coefficients of the staging combined forecasting model reach 0.897 and 0.835 respectively,and the coefficient of determination(R2)reaches 0.897 and 0.839,with a reduction in root mean square error by 10%and 17%,improving the accuracy of streamflow forecasting at Tangnaihai and Maqu stations.Through quantile mapping correction,the R2 of the forecasting models at Tangnaihai and Maqu stations is further improved to 0.926 and 0.850;c)Based on the interpretability analysis framework of SHAP machine learning,the contribution degree of forecasting factors to the runoff forecast results is identified,from high to low,as precipitation,previous month's discharge,evaporation,temperature,relative humidity and snowmelt water equivalent.It is found that the scatter distribution of the interac-tion between different forecasting factors has the characteristics of trailing or stepping.
medium and long-term streamflow forecaststaging combinationsmachine learninginterpretabilitysource regions of Yellow River