利用时序 Landsat 数据的杞麓湖面积年变化时空分析

摘要

This study proposes a spatio-temporal analysis of water body area annual changes in Qilu Lake based on time series Landsat data.Firstly,this paper uses different methods to extract water from Landsat data.Then,quantitative comparison is made on the results of different water extraction methods with the result of visual interpretation.And then,the modified normalized difference water index method is considered to be the best method of extracting Qilu Lake area.In the end,use this method to extract 2000 to 2015 Qilu Lake area,getting nearly 16 years of changes in water area,and then give an analysis of change tendency of each year and an analysis of quadrant-azimuth.The results showed that water area of Qilu Lake has gradually shrunk in nearly 16 years;in the first decade,the area change has a slow decreasing trend;in the last five years,the speed of area decline is faster,and the total area of the lake in 2015 is only half of that in 2000;in space,an outside-in shrink is happen,but the most serious region is southwest of the lake.%针对近些年云南省杞麓湖面积不断缩减的问题，提出了利用时序 Landsat 数据对杞麓湖进行面积年变化时空分析。以 Landsat 系列卫星作为数据源，采用不同方法进行水体信息提取；将水体提取方法结果与目视解译结果定量比较，确定改进归一化指数法为提取杞麓湖面积的最佳方法；利用此方法提取2000～2015年所有年份干季的杞麓湖面积，得到近16年的水体面积年变化情况，并进行逐年变化趋势分析和象限方位分析。结果表明：时间上，近16年杞麓湖水体面积逐渐缩减，前10年面积变化呈缓慢减少趋势，近5年面积缩减速度加快，2015年的湖水总面积仅是2000年的一半；空间上，整个湖泊由外而内缩减，但以西南方向缩减最为明显。