Based On The TVDI And MPDI Index Of The Spatio-temporal Variation Regularity Of Drought In Huaihe River Basin

As one kind of worldwide natural disaster across large scale, drought significant economic, social and environmental consequences. Compared to other disasters, drought is a typical accumulative disaster which could persist for several years and cause significant damage and harm the local industry and agriculture, even impose a tough burden upon the residents. The huaihe river basin is located in the eastern part of our country, mainly are the plains.This area is one of important agricultural products base in our country, so drought is wreaking havoc on development, and what is more, this area is typically ecological fragile zone. Therefore, it has an important practical significance on taking objective, positive and effective measures to monitor drought information and minimize losses.This paper collected a variety of drought remote sensing monitoring information at home and abroad. Summarized the drought remote sensing inversion models, Choose The huaihe river basin which affected by the extreme drought events as the research object, using MOD11A2 and MOD13A2 which are come from the synthesized product MODIS data to obtain the normalized difference vegetation index (NDVI) and land surface temperature (Ts), build the Ts-NDVI feature space.Based on AMSR-E passive microwave remote sensing data we have built MPDI drought index. And further verify MPDI drought index in the applicability of the huaihe river basin.Then, Through the TVDI and MPDI Index are compared with the measured soil moisture and the standardized precipitation index (SPI).the study area for the long dynamic remote sensing monitoring and evaluation in 2006-2010. Including the following aspects:(1) Using MODIS data products, extract (NDVI, Ts) and transform projection by the MRT software, and then built Ts-NDVI feature space, finally obtained temperature vegetation dryness index (TVDI) of every 16 days from 2006 to 2010 by Vc++6.0 of the huaihe river basin. Divide the soil moisture into five grades by the value of TVDI, get five years drought grade space distribution of the study area.Overall, the eastern part of the study area in HuaiYin,. LinYi etc. are almost in the wet and extremely wet; The middle of study area in SuXian, FuYang, XuChang and ZhuMaDian expressed drought and extremely drought for most of the time.Results show that, The TVDI index have obvious negative correlation with the measured soil moisture, namely bigger the value is, more arid it is. The TVDI can reflect the status of the surface soil moisture in the study area, as the drought evaluation index is reasonable.(2) Using AMSR-E vertical and horizontal polarization mode 4 band passive microwave remote sensing data, by the formula, we have built MPDI drought index of the huaihe river basin from 2006 to 2010. The MPDI index is compared with the AMSR-E soil moisture product, the precipitation and the standardized precipitation index. Results show that, The AMSR-E soil moisture product compared with precipitation and SPI, the change trend of vary widely on the time series. So the AMSR-E soil moisture product does not apply to the huaihe river basin. However, MPDI drought index correlation with precipitation and SPI is better. So The MPDI drought index is more applicable to the drought research in the huaihe river basin.(3) It can obtain the time sequence diagram in each stations of MPDI and TVDI drought indices and the measured soil moisture and the SPI drought index by Comparison and analyzing in the change of time relationship of seven meteorological stations in the huaihe river basin from 2006 to 2010We find that TVDI index and negatively correlated with the measured soil moisture overall trend and the MPDI index and the measured soil moisture was positively related to general trends. From the tendency of the MPDI and TVDI drought indices, The change trend of each index in each of the sites and concentration distribution trend is consistent.it can beseen that the two drought indices can better reflect the spring and winter drought every year.TVDI and MPDI index to a certain extent, can accurately reflect the drought conditions arising out of the study area.(4) Comparison and analysis of huaihe river basin in 2006-2010 in December, January and February TVDI and MPDI drought indices and spatial distribution condition of the measured soil moisture, get two drought indices with the measured soil moisture spatial sequence diagram. The overall trend of the MPDI and TVDI drought indices on the spatial distribution is basically the same.Especially in the west and southwest of the study area. Spatial change trend of drought range from the west and southwest gradually expanded to central and eastern regions. But the parts in the study area there are difference in the degree of drought, particularly in severe drought regions.