Remote sensing monitoring and temporal-spatial analysis of surface water body area changes of lakes on the Yunnan-Guizhou Plateau over the past 30 years
The data on the surface areas of lakes on the Yunnan-Guizhou Plateau over the past 30 years(1985-2015) are extracted from the TM and ETM+ and OLI remote sensing images in this paper.Using five water indexes including Normalized Difference Water Index(NDWI),Modified Normalized Difference Water Index(MNDWI),Enhanced Water Index(EWI),New Water Index(NWI) and Automated Water Extraction Index(AWEI),we evaluate the accuracy of the above 5 indexes and analyzed the area variations of surface water body with proper water index based on lake's individual characteristics.The results show that the total surface water body areas are increased by 30.86 km~2 from 1985 to 1995,then reduced by 48.12 km~2 from 1995 to 2015.The Lakes Qilu and Yilong have the greatest area changes among the investigated 10 lakes.The correlation analysis between the area change of each lake and annual average precipitation,annual average evaporation,annual average temperature,vegetation-covered area,human activities of each catchment shows that:the lakes have a spatial heterogeneityresponse to regional climate change.The surface area changes of these lakes are negatively related to the local temperatures and evaporations,while positively related to the local precipitations.There is a weak correlation between the surface water body areas and vegetation-covered area.Human activities could be one of the important causes of the area shrinking of surface water bodies on the Yunnan-Guizhou Plateau.