近45年泸沽湖水体面积变化遥感监测

Remote Sensing Monitoring of Water Body Area Changes in Lugu Lake in Recent 45 Years

利用1974、1986、1993、2003、2013、2018年陆地资源卫星(Landsat)遥感影像数据以及数字高程模型(DEM),以泸沽湖为研究区,对比了目前常见的7种水体指数模型,采用精度最高的经验型归一化差异水体指数ENDWI提取了泸沽湖不同时期的湖泊面积,最后结合气象资料综合分析,结果表明,泸沽湖湖泊面积与年降水量变化基本一致,呈正相关关系,与年均气温基本呈负相关关系,气温升高,水体蒸发加剧,以致在降水量恒定的情况下,湖泊面积随气温上升而减小。泸沽湖湖泊面积变化主要受草海面积变化的影响,近45年来,湖泊面积总体趋于稳定。

Based on the Landsat numeric remote sensing image data in 1974,1986,1993,2003,2013,2018 and DEM,Lugu Lake was taken as study area.In this paper,seven common water body index models accuracy was evaluated,then the lake area datum was extracted in different time by proper water index model of ENDWI(Empirical Normalized Difference Water Index).Finally,a comprehensive analysis was conducted on the variations of Lugu lake area by meteorological data.The result showed that the lake area of Lugu Lake was basically the same as the annual precipitation,which was positively correlated with it,and negatively correlated with the annual average temperature.As the temperature increased,water evaporation intensified,so that the lake area decreasd with the temperature increased under the condition of constant precipitation.The area change of Lugu Lake was mainly affected by the change of Caohai area.Over the past 45 years,the lake area has generally stabilized.