利用2017/02/27与2017/05/18两期Landsat 8遥感影像数据,反演得到地表温度和植被指数,构建LST-Ⅵ特征空间,并对建立的温度植被干旱指数进行分级分析与差值变化监测.主要结论如下:①两期影像LST-Ⅵ特征空间整体上均近似呈现三角形,MSAVI指数拟合的干湿边方程结果均优于NDVI指数,平均R2为0.769 9.②研究区干旱等级变化整体呈现“三增两减”的特征,其中中度干旱面积增加3 694 km2,增幅高达225.76％,并且增加来源主要是轻度干旱等级.③研究区干旱等级差值检测以等级增加为主,增加总面积为5435.07 km2,但等级增加与等级降低均主要为变化一个等级.整体而言,研究区干旱等级逐渐增加,干旱不断加强.%Two Landsat 8 satellites remote sensing images at 2017/02/27 and 2017/05/18 were used to retrieve land surface temperature and vegetation index,then using them to construct feature space.According to the feature space,temperature vegetation drought index was established to do the grading analysis and differential change monitoring.The main conclusion was as follows:(1) In both remote sensing images,the whole LST-Ⅵ feature space was approximately triangular.The fitted dry and wet side equations based on MSAVI index were better than NDVI index,the mean R2 was 0.7699.(2) The overall drought grade change in the study area is characterized by'three increase and two decrease',of which moderate drought area increased by 3 694 km2,the increase is as high as 225.76％.In addition,increased sources were mainly from mild drought levels.(3) In the study area,drought grade difference detection showed that grade increase was the main part,and the total increased area was 5 435.07 km2.What's more,grade increase and grade decrease were mainly a grade of change.As a whole,drought level in the study area was increasing gradually and the drought was steadily strengthening.
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