Study On Drought Monitoring Based On HJ1A,1B Remote Sensing Data-Application In North Anhui Province, China

Drought has direct negative impact on economy and society, especially on agriculture. Compared with other disasters, it appears more frequently with longer duration and larger affected area, thus causes more losses. Drought arouses more and more attention of the public. Drought monitoring, which timely and accurately reflects the characteristics of droutht—the affected area of drought, extent and trends, has profound significance to the whole society.In a traditional way to evaluate drought, Standardized Precipitation Index (SPI) was choosed as drought indicator, using the precipitation data over the years 1957 to 2006 in Anhui Province. Statistics and summerrization are made. In comparing the time scale effect of SPI (1-month, 6 months and 12 months), the 12-month time scale SPI was found the most suitable for long-term evaluating drought.As the soil moisture is an important factor to determine the situation of agriculture in temporal and spatial change, the soil moisture of tested sites was calculated by inverse distance weighted interpolation, so interpolation maps of soil moisture is obtained. However the traditional method of measurement of soil moisture consumes a lot of time and energy,Remote sensing images are continuous data and can be updated rapidly, which can reflect temporal and spatial distribution of underlying surface such as the type of land use, soil and vegetation. Combined measured soil moisture data with remote sensing data to evaluate drought, can largely make up the aforementioned deficiencies of traditional monitoring methods. So research on the application of remote sensing of soil moisture inversion method has great significance for evaluation and monitoring of drought. In this paper, based on a full review of domestic and international progress in drought monitoring and evaluation, the approach of how to use "ground truth plus remote sensing interpretation" to monitor drought was focused.China's latest self-developed HJ satellite data was used to inversed the drought in northern part of Anhui Province.Then Vegetation Supply Water Index and the soil water study area were regressed, the formula of vegetation index transeferrd to soil moisture data was calculated, then resultant soil moisture throughout the study area was obtained. According to our assessment of the standard soil moisture drought, drought conditions on the study area were evaluated. Next, this method and the interpolation method are compared, and the combination of administrative, DEM and land use classification data on drought were analyzed too. In this paper, the application of satellite data for environmental disaster reduction was made as useful exploration, the results show that the use of HJ satellite data for environmental monitoring and evaluation of drought is feasible.