Research On Spatial Distribution Of Agriculture Drought In Hunan

Drought is the most frequently occurring natural disasters all over the world. The agricultural drought will not only lead to the reduction of agricultural production and food shortages, and if maintained for a long time it will also result in the cumulative degradation of land resources, water scarcity and the damage of the ecological environment, which will finally restrict the local agricultural industry as well as the constraints of social economic sustainable development. Therefore, the agricultural drought monitoring is necessary. If the scope of the drought, the level of development and changes in trends can be acquired timely and accurately, it will lay the practically significant foundation of further study of basic farmland protection in Hunan Province.There are a variety of agricultural drought monitoring methods. First of all, this article gives a comprehensive presentation of the indices of traditional and remote monitoring of agricultural drought. Then, Hunan is treated as a study area, the agricultural drought in which is monitored dynamically by using a remote sensing technology. Integrating RS and GIS technology in3S technology and combining the EVCI of MODIS, TCI and precipitation factors of TRMM data, the EVCI, TCI and RCI are given their respective weights based on their different sensitivity to agricultural drought. Based on above all, the remote sensing monitoring model of CDCI is founded, which is applied to monitor the drought in Hunan agricultural crops.After the correlation analysis of the CDCI from July to September in2009and the CI acquiring from88meteorological stations in the same period in Hunan, a prominent linear correlation between CDCI and CI index is shown and the best combination of EVCI, TCI and RCI weights are proved to1/5,2/5and2/5. Meanwhile, the integrated model’s applicability of agricultural drought monitoring in Hunan Province are validated, which indicates that using remote sensing technology to monitor drought in Hunan Province is a certain practicality.In this article, the spatial distribution of drought in Hunan agriculture and the areas of different drought grades are extracted by using the CDCI to monitor and analyze the agricultural drought conditions from July to September in Hunan Province from2008to2010. The comparative analysis results show that the results of the agricultural drought monitoring data obtained by remote sensing are basically consistent with that of the actual, which shows that the CDCI can accurately reflect the spatial and temporal variation of autumn drought in Hunan crops, and shows CDCI model is suitable for remote sensing monitoring of agricultural drought in such Hunan southern humid areas.