Ecohydrological Regime Changes in Poyang Lake Basin Under Future Climate Scenarios
In this study,we explored how the hydrological regime in Poyang Lake basin might change un-der the influence of climate change,focusing on runoff trends,extreme flows and pulse ratios.We aimed to provide a scientific basis for ecohydrological management and protection of the basin and enhance resilience to climate change.To begin,we constructed a distributed time-variant gain model(DTVGM)to simulate runoff in the Poyang Lake basin,based on daily runoff data recorded at four hydrological stations(Waizhou,Lijiadu,Meigang,Dufengkeng Stations).Data from 1980-2003 was used for calibration and da-ta from 2004-2016 was used for validation.The Nash-Sutcliffe efficiency coefficients(NSE)were in the range of 0.72-0.84 for the calibration period and 0.65-0.82 for the validation period,indicating the reliabil-ity of the DTVGM model.Runoff was then simulated in the Poyang Lake basin for the period 2020-2100 using four climate scenarios of SSPs-RCPs combinations(SSP 1-2.6,SSP2-4.5,SSP3-7.0,SSP5-8.5).Combining the Mann-Kendall trend test and eco-hydrological index range method(IHA-RVA),we quan-titatively assessed and analyzed the change degree of eco-hydrological indicators at seven stations in Poyang Lake basin under the four climate scenarios.Results show that:(1)Future runoff in the Poyang Lake basin shows an increasing trend,with an increase range of 18.5％-30.3％,and the increase under the scenario of SSP5-8.5 is the highest.(2)The increase of monthly average runoff in wet season(March to August)is more obvious than in dry season(September to the following February).The increase in runoff reaches 20％from May to September,and the maximum annual extreme runoff will occur 1.0 to 17.8 days sooner than at present.(3)Under the climate change scenarios,the overall hydrology of Poyang Lake basin will change only slightly,and the highest change degree occurs at the Qiujin Station(21.2)and the lowest change degree occurs at Hushan Station(19.2).However,the changes in the compo-nent indices for monthly average flow(Ⅰ),annual extreme flow(Ⅱ)and flow change(Ⅴ)are relatively high,with an average degree of 22.8.Our results provide scientific support for predicting and preparing for climate induced changes in the eco-hydrology of Poyang Lake basin.
climate changeecological hydrological situationhydrological change degreePoyang Lake basin
万方数据
维普
