近30a杞麓湖面积变化遥感监测分析

Remote Sensing Monitoring and Analysis of the Area Change of Nearly 30a Qilu Lake

摘要: 作为云南九大高原湖泊之一的杞麓湖在区域经济发展与生态环境安全中扮演着重要的角色。目前针对该地区湖泊面积变化的长时间、高密度的监测研究较少，本文以时间序列TM、OLI遥感影像以及HJ-1A为数据源，提取了杞麓湖1987~2017逐年的MNDWI指数，结合OSTU算法实现自动阈值设置，最终得出了近30年杞麓湖逐年的湖泊面积数据。通过分析发现，1)近30a中，杞麓湖面积总体呈现缩减的趋势，尤其是1987~1989年和2011~2013年湖泊受到重大干扰，湖泊面积显著缩减；2)杞麓湖在空间上的变动表现为湖泊外围均有所缩减，西部和西南部缩减严重，东北方向和正东方向以及东南方向受到的影响相对较小。

Abstract: As one of the nine plateau lakes in Yunnan Province, Qilu Lake plays an important role in regional economic development and ecological environment security. At present, there are few long-term and high-density monitoring studies on the change of Lake area in this area. In this paper, time series TM, OLI remote sensing image and HJ-1A are used as data sources to extract the annual MNDWI index of Qilu Lake from 1987 to 2017. Combined with the Otsu algorithm to achieve automatic threshold setting, the annual Lake area data of Qilu Lake in the past 30 years are finally obtained. Through analysis, it is found that: 1) in the past 30 years, the area of Qilu Lake has been reduced in general, especially in 1987-1989 and 2011-2013, when the lake was greatly disturbed, the area of the lake has been significantly reduced; 2) the spatial changes of Qilu Lake show that the periphery of the Lake has been reduced, the west and southwest have been seriously reduced, and the northeast, the east and the southeast have been relatively less affected.