Method Of Drought Early Warning In Ningxia

The drought is one of the major agrometeorological disasters, of which the influences on the agricultural production and the food safety have aroused widespread concern. To reduce the loss caused by the drought, it has important practical significance to carry out the forecasting and warning method, as well as to study the index system. Taking Ningxia Hui Autonomous Region, one of the Chinese main agricultural drought areas, as the study object, based on MODIS satellite remote sensing data, we constructed drought indexes as the temperature-vegetation index and temperature difference-vegetation index. Then, we constructed the soil moisture monitoring index and inverse calculated the soil weight moisture content, moreover, we started the prediction research on the soil moisture based on the BP neural network. The main conclusions are as follows,:(1) Based on Temperature Vegetation Drought Index (TVDI), temperature enhanced vegetation index of drought index (TEDI), Temperature Vegetation Drought Index (DTVDI) and temperature enhanced vegetation index of drought index (DTEDI), respectively, as the soil moisture monitoring index, inverse Le Ning2000-2004Summer regional soil moisture, and based on the site observation data, the comprehensive comparison results show that the inversion effect, Ningxia, DTEDI in soil moisture inversion in a better performance, the DTVDI performance(2) Based on the BP neural network, in different drought index obtained by inversion of soil moisture based on the data of precipitation and evaporation, combined with the actual observation data, carry out the soil moisture prediction, the results show that, in combination with the ten-day precipitation and evaporation were obtained to predict the soil moisture and soil moisture observation values correlated better, here based on the combination of the Pentecost, precipitation and evaporation, based on Temperature Vegetation Drought Index (DTVDI type) were obtained to predict the weight of the soil water content and the measured values correlate better with.The above results indicate that, based on MODIS construction of drought index DIVDI, and based on the BP neural network to carry out soil moisture prediction method is feasible, especially in the Ningxia region has certain applicability and application value.