Investigation on spatial and temporal variabilities and changes of hydrological regimes in Ganjiang River Basin
As the largest sub-basin of Poyang Lake Basin,Ganjiang River Basin serves as an important water source area in the middle and lower reaches of the Changjiang River.Investigating the hydrological regimes of the Ganjiang River Basin may as-sist for understanding the hydrological evolution mechanism in this region.To this end,based on the daily rainfall and runoff moni-toring data of Ganjiang River Basin from 2000 to 2021,we used statistical analysis(Mann-Kendall test,correlation analysis),combined with using HYPE hydrological simulation and PEST automatic calibration technology to study the hydrological process and its spatial and temporal variation of parameter sensitivity index,runoff and rainfall.The results showed that:① hydrological variables exhibited certain spatial and temporal changes within the watershed.On the annual scale,both runoff and precipitation showed fluctuations with overall slight upward trends,runoff had a clear positive correlation with precipitation.The regulating res-ervoirs within the Ganjiang River Basin may impact the hydrological regime.On the monthly scale,highest runoff and precipitation occurred in June and lowest values occurred in January.In terms of spatial distribution,both annual mean runoff and precipitation were higher in the eastern and northern parts of the Ganjiang River Basin.② The runoff simulation was most sensitive to the pa-rameter mactrsm of soil water content threshold that describes macropore flow and surface runoff occur.③HYPE model well simu-lated the runoff dynamics observed in outlets of the Ganjiang River Basin(Waizhou gauging station)and its representative sub-basin Yifeng River catchment(Yifeng gauging station),with Ens varying between 0.60 and 0.86.HYPE model outperforms in Waizhou gauging station than the Yifeng gauging station.On the annual scale,soil moisture,evapotranspiration and surface runoff showed overall increasing trends in the sub-basin represented by Yifeng discharge gauging station.Regarding spatial variation,the sub-basin represented by Waizhou discharge gauging station had higher soil moisture,lower evapotranspiration and higher surface runoff compared to the sub-basin represented by Yifeng discharge gauging station.④According to baseflow partitioning,Yifeng and Waizhou sub-basins showed different runoff generation regimes.We noted higher contribution of saturated groundwa-ter to total runoff in the sub-basin of Yifeng gauging station,while higher contribution of surface runoff to total runoff in the sub-basin of Waizhou gauging station.The spatial difference in accuracy of hydrological simulation is mainly associated with the het-erogeneity of catchment characteristics and changes in hydrological processes.
hydrological regimesspatial and temporal variabilitiesMann-Kendall trend testtrend analysishydrological sim-ulationHYPE modelGanjiang River Basin
万方数据
维普
