基于温度植被干旱指数的衡邵干旱走廊监测分析

Monitoring and Analysis of Heng-Shao Drought Corridor Based on Temperature Vegetation Drought Index

衡邵(衡阳-邵阳)干旱走廊是湖南省旱灾发生最频繁、最广泛、最严重的地区,干旱给衡邵地区人们的生活产生了巨大影响,对衡邵地区进行相关监测,这不仅与该地区社会经济和生态环境发展有关,也对保护我国南方地区生态环境起到了至关重要的作用。利用2016-2020年1月、4月、7月和11月的MODIS地表温度产品提取地表温度(LST)、植被指数产品提取归一化植被指数(NDVI),通过构建特征空间,得到温度植被干旱指数(TVDI)等级分布图。结果表明:(1)在空间分布上,衡邵干旱走廊地区东南部每年都会发生旱灾,南部受旱情影响大于北部;(2)在时间分布上,7月份旱情以重旱和中旱为主,其中重旱区域面积占18.56%,中旱区域面积高达50.28%。同时,用降水距平和温度插值进行验证,发现TVDI能较好地反映干旱情况。

Drought disasters in the Heng-shao Drought Corridor are the most frequent,widespread and severe areas in Hunan Province,which has had a huge impact on people's lives.Drought monitoring in Heng-shao area is not only related to the socio-economic and ecological environment development in the area,but also plays a vital role in protecting the ecological environment in southern China.This paper uses MODIS’s surface temperature products from January,April,July and November 2016 to 2020 to extract land surface temperature,and vegetation index products to extract normalized vegetation index.The distribution map of temperature-vegetation dryness index levels is obtained by establishing a NDVI-LST space.Using precipitation and temperature data for verification,it is found that the drought can be better reflected.The results show that:①in terms of spatial distribution,droughts occur every year in the southeast of the Heng-shao Arid Corridor,and the south is more affected by drought than the north;②In terms of time distribution,droughts in July were dominated by heavy and moderate droughts,with 18.56%of the area of severe drought and 50.28%of the area of moderate drought.