Evolution characteristics of drought in the Panzhihua and Liangshan regions of Sichuan Province based on NDVI-LST model in the past 20 years
With the continuous intensification of global warming and the frequent occurrence of regional drought events,many mea-sures to cope with drought events have been taken in recent years.In order to analyze the effectiveness of relevant measures,the Panzhi-hua and Liangshan Prefecture(referred to as"Panxi Area")in Sichuan Province is taken as an example to study the evolution character-istics of drought in the region in the past 20 years,so as to serve local production and development.The Normalized Difference Vegeta-tion Index(NDVI)and Land Surface Temperature(LST)data of MODIS were used to calculate the Temperature Vegetation Drought In-dex(TVDI)in Panxi Area from 2003 to 2022,and the changes of TVDI on different time scales and drought evolution characteristics over the past 20 years were analyzed.The results are as follows:(1)Droughts in the Panxi area mostly occurs from March to May in spring,and the TVDI value is the lowest around October each year,which is also the period less prone to drought.(2)The drought in Panxi Area was alleviated year by year,and the areas of drought-free and drought-severe areas monitored by TVDI had little change.The area of light drought has increased,with an average increase of 5.30%after 2013.On the other hand,the area of medium drought has decreased,with an average decrease of 5.67%after 2013.(3)The drought in Zhaojue,Butuo and Yuexi has eased obviously,while the drought in Muli,Miyi and Huili has an aggravation trend.(4)The regional drought is relatively stable in most areas,accounting for 82.59%of the total area,while the drought center changes little from south to north,but it has a trend of westward migration.
MODISTVDIPanzhihua and Liangshan regionsdrought evolution
NETL
NSTL
万方数据
