Response of hydrology of Dongting Lake to drought conditions of Dongting Lake basin and its attribution
[Objective]The fluctuation of the hydrological regime in river-connected lakes has been exacerbated by the extreme climate change and intensive human activities.Therefore,it is crucial to investigate the impact of drought occurred in basin on the hydrological conditions of river-connected lakes.[Methods]Dongting Lake,a typical river-connected lake in China,together with its basin,were taken as the study object.Five representative meteorological and hydrological stations in Dongting Lake basin were selected from 2010 to 2020 and 2022(a typical drought scenario),including precipitation,temperature,and water level.This study combines the hydrological trend analysis,standardized precipitation Index(SPI),and regression analysis to investi-gate the characteristics of meteorological and hydrological factors,drought conditions,and the relationship between water level of Dongting Lake and the drought conditions in Dongting Lake basin.[Results]The result showed that the precipitation of Dongting Lake basin displayed a slight increasing trend during the study period.No significant variation in temperature is detected,where-as the temperature of Li river basin exhibited low,ranging from 16.07 to 17.41℃.The water level of Dongting Lake displayed a general fluctuating and increasing trend,ranging from 23.63 to 25.81 m.The SPI of Dongting Lake basin varied from-0.86 to 0.31 during study periods,with the proportion of 91％for normal years and 9％for light drought years.The drought conditions of Dongting Lake basin exhibited a trend of increasing firstly and then decrease,with the high frequency for normal level(0.18％～0.64％)and wet level(0.18％～0.36％).In 2022,the water level of Dongting Lake increased to 30.45 m in June,then de-creased sharply.From January to June 2022,the drought condition in Dongting Lake basin is wet and normal levels,but later it deteriorates to moderate and severe drought levels.The water level of Dongting Lake showed a strong positive correlation with the precipitation and water discharge.[Conclusion]The majority of study years in Dongting Lake basin were classified as normal years,while the remaining years were categorized as slight drought years.The peak water level of Dongting Lake in 2022 occurred in June,which is earlier than previous years in July.Moreover,the water level of Dongting Lake in April,May,and July showed a significant correlation with the SPI index of Dongting Lake basin,reflected the response of lake water level on drought condition in the basin,and revealed the feature of"summer drought"in Dongting Lake caused by abnormal precipitation in Dongting Lake basin.Our findings can offer a scientific support for hydrological and agricultural departments in managing meteorological disas-ters and implementing measures to protect agricultural production.
Dongting Lake basindroughtprecipitationwater leveldriving mechanism
万方数据
维普
