山东省干湿转换期土壤水分MODIS遥感监测

由于2012年春夏过渡时期山东省降水时空分布不均,前期全省大部分地区出现旱情,后期降水偏多。为及时掌握干旱分布及变化情况,利用MODIS地表温度数据(MOD11A2)和植被指数数据(MOD13A2),结合土壤水分自动站的实测数据,采用温度植被干旱指数法,构建了LST-NDVI、LSTEVI特征空间,反演了2012年6~7月山东省干湿转换期的土壤水分,分析了干旱空间分布及变化特征。结果表明:LST-NDVI特征空间反演精度为82.95%,LST-EVI特征空间反演精度为84.33%,精度提高了1.66%。前期山东省中南部、西部出现旱情并以轻旱为主,后期由于降水旱情明显缓解,干旱面积减少了65 427 km2。基于MODIS数据利用温度植被指数法在本区域进行干旱监测是可行的。

Research on Soil Moisture Monitoring Using MODIS Data During the Drought /Wet Conversion Period in Shandong Province

Since the uneven spatial and temporal distribution of precipitation,the drought occurred at the end of spring and the beginning of summer in 2012 in Shandong Province. In this paper,the LST-NDVI,LST-EVI feature space were established using temperature vegetation index method based on MODIS product data MOD11A2,MOD13A2 and soil moisture data from automatic stations,and the soil moisture was retrieved to monitor the spatial and temporal distribution of drought in Shandong Province from June to July2012. By comparing the monitoring results with the measured values,the predicted accuracy of LST-NDVI and LST-EVI feature space was 82. 95% and 84. 33%,respectively,which showed that the predicted accuracy of LST-EVI improved by 1. 66%. From June 10 to June 25,the drought occurred in the central,south and west regions of Shandong Province,and from June 26 to July 10,due to the precipitation,the drought degree obviously mitigated and the drought area reduced 65 427 km2. So TVDI method based on MODIS data could be used to monitor the relative humidity of the soil in Shandong Province.