山东微山湖近30年湖面面积时空变化及驱动机制

The Spatial and Temporal Dynamic Changes and Driving Forces in the Surface Area of Weishan Lake of Shandong Province in Recent 30 Years

采用1986年7月、1996年7月、2006年7月和2016年7月的4期Landsat数据,利用归一化水体指数模型(NDWI)和修正归一化水体指数模型(MNDWI)提取山东微山湖水域面积,研究近年来微山湖湖面的动态变化。以最大似然分类结果作为标准,验证了用NDWI和MNDWI模型提取面积的精度,得出NDWI模型所提取的湖泊面积更符合实际情况,湖泊总面积从1986年的1338.41km^2减少到2016年的1233.26km^2,缩小了8.5%,到2000年后期微山湖面积基本稳定在1200km^2左右。然后利用湖泊面积动态模型分析了微山湖面积变化及其驱动机制,结果表明近年来随着温度的逐年升高,降雨量呈献出不稳定的变化趋势,加上大量的蒸发等综合作用,导致了微山湖面积的缩小。多年来微山湖流域内随着人口数量的增加、耕地面积以及建筑面积的不断扩张导致需水量逐渐增大,这也是导致湖面面积减少的主要原因之一。开展微山湖湖面时空动态变化及其驱动机制研究,对于湖泊生态系统的保护具有重要的理论和实际意义。

Based on the Landsat data of July 1986,July 1996,July 2006 and July 2016,the area of Weishan Lake in Shandong Province was extracted by using the Normalized Difference Water Index(NDWI)and the Modified Normalized Difference Water Index(MNDWI),and the dynamic changes of the surface of Weishan Lake in recent years were studied.Based on the maximum likelihood classification results,the accuracy of the lake area extracted by NDWI and NDWI models is verified.It is concluded that the lake area extracted by NDWI model is more consistent with the actual situation.The total area of lakes decreased from 1338.41 km^2 in 1986 to 1233.26 km^2 in 2016,and decreased by 8.5%.By the end of 2000,the area of Weishan Lake was basically stable at approximately 1200 km^2.Then,the dynamic model of Lake area is used to analyze the change of Lake area and its driving mechanism.The results show that in recent years,with the increase of temperature year by year,the precipitation presents an unstable trend of change,coupled with a large number of evaporation and other comprehensive effects,resulting in the reduction of Lake area.Over the years,with the increase of population,the expansion of cultivated land and building area in Weishan Lake Basin,water demand has gradually increased,which is also one of the main reasons for the decrease of lake surface area.It is of great theoretical and practical significance for the protection of lake ecosystem to study the spatio-temporal dynamic changes of lake surface and its driving mechanism in Weishan Lake.