丹江口水库水域变化遥感监测研究

Monitoring of water area change in Danjiangkoureservoir area based on remote sensing data

基于2013—2020年的Landsat8遥感数据,利用PIE-Engine遥感大数据平台,以改进的归一化水体指数(modified Normalized Difference Water Index,mNDWI)和植被指数(Normalized Difference Vegetation Index,NDVI)为指标,采用决策树法获得丹江口水库月度水域数据集,从月度、季度和年尺度上对丹江口水库的水域面积时间变化进行研究,并探讨其原因,同时研究了库区消落带的空间分布和时间演化特征。结果表明:整体上,2013—2020年丹江口水库的水域面积总体呈上升趋势,最大水域面积为751.36 km 2(2017年10月),最小水域面积为294.93 km 2(2014年4月);在季度尺度上,无论通水前后,库区秋冬季的水域面积最大,春季的水域面积最小;丹江口水库的消落带大部分分布在丹江库区,南水北调中线一期工程通水后,消落带面积较通水前增加,且主要分布在丹江库区中部和北部地区。

Firstly,landsat8 remote sensing data from 2013 to 2020 were used based on PIE-Engine remote sensing big data platform.Modified Normalized Difference Water Index(mNDWI)and Normalized Difference Vegetation Index(NDVI)were used.The monthly water area data set was obtained by decision tree method.Then,the temporal changes of the water area of Danjiangkou Reservoir were studied at monthly,quarterly and annual scales,and the causes were discussed.At the same time,the spatial distribution evolution characteristics of water-level fluctuation zone in the reservoir area were studied.The results show that:(1)On the monthly scale,the water area of Danjiangkou Reservoir is on the rise from 2013 to 2020,with the maximum area of 751.36 km2(October2017)and the minimum area of 294.93 km2(April 2014).At the seasonal scale,the water area of the reservoir area is the largest in autumn and winter,and the smallest in spring,regardless of before and after water diversion.(2)Most of the water-level-fluctuation zone of Danjiangkou Reservoir is distributed in the Danjiang reservoir area.After the first phase of the middle route of the South-to-North Water Diversion Project is put into operation,the area of the water-level-fluctuation zone increases,and it is mainly distributed in the central and northern areas of the Danjiang reservoir area.