Hydrological Characteristics and Trends of Dongting Lake over the Last 20 Years
The hydrological regime plays an important role in determining the quality of aquatic ecosys-tems.Studying the hydrological changes in lakes,rivers and other water bodies provides a scientific basis for water safety management and ecological restoration.In this study,we analyzed change in the hydro-logical regime of Dongting Lake from 2000 to 2020 and explored the effect of inflowing water on chang-es in hydrology using random forest regression.The study was based on hydrological data from 8 repre-sentative stations(Chenglingji,Yingtian,Nanzui,Yangliutan,Taoyuan,Mituosi,Shadaoguan,Kangjia-gang)and Landsat 5 and 8 satellite remote sensing data.Results show:(1)In the past 20 years,the annual average water level of Dongting Lake fluctuated widely,with water levels in 2002,2005,2012 and 2016 significantly higher than the average,and levels in 2006 and 2011 significantly lower than the average.The changes in water level within a year were more regular,displaying a single peak and distinct levels in the wet and dry periods.(2)The maximum annual water area of Dongting Lake decreased by 99.70 km2 from 2000 to 2020,but the minimum water area increased by 188.85 km2.(3)The effective connectivity of the water surface of Dongting Lake decreased significantly over the past 20 years.In general,connec-tivity increased along the west-east axis and decreased along the north-south axis.(4)Changes in water level were closely related with flow rates of the three major inlets(Ouchikou,Songzikou,and Taipingkou)and closely related to the overall hydrological regime of Dongting Lake,with Ouchikou having the largest impact.
hydrological regimewater areahydrological connectivityDongting Lake
万方数据
维普
