干旱对赤峰市不同生态系统影响的差异

The Difference Impacts of Drought on Different Ecosystems in Chifeng

以2000-2019年生长季5-9月MODIS(moderate resolution imaging spectroradiometer)归一化植被指数(normalized difference vegetation index,NDVI)和地表温度(land surface temperature,Ts)数据构建Ts-NDVI特征空间,利用温度植被干旱指数(temperature vegetation dryness index,TVDI)研究了赤峰市近20年干旱的时空变化特征及其对不同生态系统的影响。结果表明:赤峰市春旱严重,但旱情以轻旱为主,地域分异呈“东旱西润”格局。干旱对不同植被生态区的影响差异显著,平均影响强度表现为农田>灌丛>草地>森林,但草地生态系统是对干旱响应的敏感区和脆弱区,其次是灌丛和农田,森林生态系统最不敏感。

The temperature vegetation drought index(TVDI)was used to monitor the temporal and spatial changes of drought and its impacts on different vegetation ecosystems in the last 20 years in Chifeng,Inner Mongolia,China in this paper.The TVDI was created by using the normalized difference vegetation index(NDVI)and land surface temperature(Ts)data from Moderate-resolution Imaging Spectroradiometer(MODIS)collected in Chifeng during the growing season(from May to September)of 2000-2019.The results illustrated that the droughts occurred frequently in spring and they were manly slight drought;the pattern of drought in Chifeng obviously taken in dry in the east and humid in the west.The impact of droughts on vegetation ecosystems was in different degree of severity,usually,farmland>bush>grassland>forest.On the other hand,the most sensitive and fragile ecosystem to drought was grassland,the less sensitive ecosystem were bush and farm,and the most insensitive ecosystem was forest.