基于TVDI的金沙江下游干旱时空变化及影响因素研究
Spatiotemporal Variation and Drivers of Drought based on TVDI in the Lower Reaches of the Jinsha River
陈国建 1方宁 1李剑峰 1吴兴华 2董先勇3
作者信息
- 1. 上海勘测设计研究院有限公司,上海 200335;中国长江三峡集团有限公司长江生态环境工程研究中心,北京 100038
- 2. 中国长江三峡集团有限公司,武汉 430010;中国三峡新能源(集团)股份有限公司,北京 100053
- 3. 中国三峡新能源(集团)股份有限公司,北京 100053;中国三峡建工(集团)有限公司,成都 610000
- 折叠
摘要
金沙江下游是中国干热河谷的主要分布区之一.该地区干旱灾害频发,然而气候变化下该区域的干旱的时空变化规律及影响因子仍不清楚.本文基于MODIS地表温度和NDVI数据反演 2000-2020 年的温度植被干旱指数(TVDI),监测研究区干旱的时空变化规律及其驱动力.研究结果如下:(1)研究期内TVDI指数与0-7 cm的土壤湿度高度相关,表明TVDI可以准确反映研究区的干旱情况;(2)TVDI在研究区的分布具有高度空间异质性,多年平均TVDI值为 0.59,干旱水平介于正常和干旱之间;(3)从 2000-2020 年,干旱程度呈现增强趋势,变干的区域占研究区面积的 63%,其中显著变干区域占 21%,相较于2000 年,14.5%的区域在 2020 年从正常等级转变为干旱.(4)与"干的越干,湿的越湿"的现象略有不同,我们发现干的和湿的区域都主要趋向于变干.(5)86%的区域TVDI指数与年均气温正相关,其中43%的区域显著相关,升温是研究地区干旱加剧的主要驱动力.我们的研究结果可以为金沙江下游区域干旱对气候变化的时空异质性响应提供新的见解.
Abstract
The lower reaches of the Jinsha River is the main distribution area of hot-dry valleys in China.While it suffers from frequent droughts,the spatiotemporal variation and driving forces of drought in this area under climate change are still unclear.The spatiotemporal variations of Temperature Vegetation Drought Index(TVDI)and drivers of drought were explored using MODIS land surface temperature and NDVI data from 2000 to 2020.The results are fivefold.(1)TVDI was highly correlated with soil moisture content at a depth of 0-7 cm,indicating that it can accu-rately reflect the drought situation in the study area.(2)The spatial variability of TVDI was highly heterogeneous,with a multi-year average of 0.59,and the drought level was mainly between normal and dry.(3)From 2000 to 2020,TVDI showed a slightly increasing trend.It increased in 63%of the study area,and significantly increased in 21%of the study area.At the same time,the area at the dry level increased by 14.5%in 2020 from the normal level in 2000.(4)Slightly different from the standard phenomenon of"dry gets drier,wet gets wetter",we found that both dry and wet areas were becoming drier.(5)TVDI was positively correlated with annual mean temperature in 86%of the region,of which 43%of the region showed a significant correlation.The increasing temperature was the main driving force for the increase in drought in the study area.Our results can provide new insights into the spatiotem-porally heterogeneous response of drought to climate change in the lower reaches of the Jinsha River.
关键词
气候响应/干旱/干热河谷/金沙江/时空变化/温度植被干旱指数Key words
climate driven/drought/hot-dry valley/Jinsha River/spatiotemporal variation/TVDI引用本文复制引用
基金项目
Research Project of China Three Gorges Corporation(202103325)
出版年
2024
NETL
NSTL
维普
万方数据