论文部分内容阅读
西北地区深居欧亚大陆腹地,是我国干旱最严重的地区之一,开展卫星遥感资料旱情监测工作,具有重要的现实意义。利用MODIS合成产品数据MOD11A2和MOD13A2获取的归一化植被指数(NDVI)和地表温度(TS)构建TS-NDVI特征空间,依据该特征空间计算的温度植被干旱指数(TVDI)作为土壤湿度监测指标,分析了西北地区2007年6-9月每16 d的土壤湿度。研究表明,2007年6-9月,我国西北地区虽然没有发生大面积、较严重的旱情,但有较长时间和较大范围的轻旱到中旱。同时,对土壤湿度数据进行验证发现,TVDI指标基本上能够反映表层土壤湿度状况,利用温度植被旱情指数法对西北地区进行夏季干旱动态监测是可行的。
The northwestern region lives in the hinterland of Eurasia, which is one of the most serious drought areas in our country. It is of great realistic significance to carry out the drought monitoring of satellite remote sensing data. The TS-NDVI feature space was constructed by using the normalized NDVI and the surface temperature (TS) obtained from the MODIS product data MOD11A2 and MOD13A2. Based on the TVDI calculated by this feature space as the soil moisture monitoring index, The soil moisture of every 16 days from June to September in 2007 in Northwest China was analyzed. The research shows that in June-September 2007, there was no large-scale and severe drought in the northwest of China, but it took a long time and a relatively large range of mild to moderate drought. At the same time, the soil moisture data are verified and it is found that the TVDI index can basically reflect the soil moisture condition in the surface layer. Using the method of temperature, vegetation and drought index, it is feasible to monitor the summer drought in northwest China.