Research Of Remote Sensing Monitoring Of Drought In Jiangxi Province Based On VTVDI

As one of the major natural disasters in the world, drought not only hinders the economic and social development of the country, but also does harm to people’s production and life. Therefore, using remote sensing technology for dynamic monitoring of drought and obtaining the time, range, extent and trend of drought is of great significance to the drought relief and regional agricultural production. The paper summed up drought monitoring methods using remote sensing based on soil moisture stress and the response of surface vegetation. A drought monitoring model based on vegetation types taking advantage of HJ-1 data was built. The paper calculated the drought index from September 2008 to December 2015 in Jiangxi Province, and studied the temporal and spatial variation of Jiangxi over the years by the methods of time series analysis. The main contents and conclusions of the paper are as follows:(1) The land cover types were divided into vegetation and non-vegetation. The temperature vegetation drought index of the corresponding area for vegetation was obtained according to the different types of vegetation, while the temperature vegetation drought index of the corresponding area for non-vegetation was obtained using all land cover types. Combined with the inversion results of two parts, a drought monitoring model based on vegetation types was built and the temperature vegetation drought index based on vegetation types was calculated. The paper calculated the monthly monitoring results of the temperature vegetation drought index based on vegetation types from September 2008 to December 2015 in Jiangxi Province.(2) The correlation analysis of the temperature vegetation drought index based on vegetation types was carried out using the soil relative humidity, precipitation, air temperature and soil moisture data to validate the drought monitoring model based on vegetation types. The results showed that there was a good correlation between the temperature vegetation drought index based on vegetation types and the three indexes of soil relative humidity, precipitation and air temperature, and compared with the traditional TVDI, the accuracy and applicability of it in the drought monitoring is better than that of the traditional.(3) The temporal and spatial variations of drought from September 2008 to December 2015 in Jiangxi Province were studied by using some time series analysis methods. The correlation analysis results of the temperature vegetation drought index based on vegetation types and time variable showed that drought would be intensified in January, May, September, October and December and decreased in March, July, August and November. The variation coefficient of each month has a great change in space. Under the condition of the significant level of α=0.05, drought would be intensified in April, May, September and October and decreased in July and August.