Based On Modis Land Products Lst And Ndvi And Evi Shaanxi Drought Monitoring,

In recent years,drought is a world-wide phenomenon of frequent natural disasters,which has severely affected the ecological balance of environment and sustainable development of human society and economy.Shaanxi province is located in inland China,most part of the province is in the arid and semi-arid climatic zone with a fragile ecological environment,inconstant rainfall,and nine times of drought in every 10-year.It is positive significance to strengthen the monitoring of the drought,give full play to the advantages of remote sensing technology to establish a suitable model for monitoring of the drought.In this paper,domestic and foreign references of monitoring drought situation by remote sensing systematic analysis in recent years were summarized,and the study of development trends on the basis of the analysis of surface temperature and vegetation index of the necessity and possibility of joint was analyzed.Shaanxi province was selected as a specific study area.LST-NDVI characteristics space was constructed with 3S technology based on using MODIS data MODIS 11C3 Normalized Difference Vegetation Index(NDVI),Enhanced Vegetation Index(EVI) and Land Surface Temperature(LST),at the same time,combined with mathematical statistics method of the drought of 2005 to carry out monitoring and evaluation.In this paper,the main conclusions and innovation points are as follows:(1)Temperature-vegetation drought index TVDI which calculated from the characteristics of the space was used as an indicator to monitor soil moisture.Arid information models drived by remote monitoring were set up.The soil moisture inversion results of the two indexes were compared in Shaanxi Province,than the drought levels distribution was given out.(2)The space and temporal sensitivity of models were analyzed with the meteorological data from 98 weather stations and the soil moisture data of 3 layers at the depth of 10cm,20cm,50cm from 33 agro-meteorological observation points in Shaanxi Province,furthermore the application prospect of LST-NDVI and LST-EVI was discussed.(3)The result showed that TVDI-1(based on LST-NDVI) and TVDI-2(based on LST-NDVI) with the temperature anomaly mostly perform a positive correlation trend,while with the precipitation anomaly show negative relationship.Both of them with the surface soil moisture content was the most relevant,especially TVDI-2.(4)By sub-regional perspective,the applicability of this model was better in Northern Shaanxi than other area.From the province said that the use of the conditions of temperature-vegetation drought index for drought monitoring in Shaanxi Province can better reflect local drought,according to surface temperature and vegetation indices to enhance the relationship between the set up of the Drought Monitoring Model linear correlation more significantly,basically through the 0.05 level under the hypothesis testing.From meteorological data and soil moisture testing perspective,this paper set up remote monitoring of the drought model and to do as early as selected regional monitoring has good practicality,can be widely used as early as do the monitoring and evaluation work.(5)Innovation points:The index of temperature vegetation was firstly used to monitor and evaluate the drought condition in Shaanxi Province;The first time to build the feature space using MODIS data NDVI and enhanced vegetation index and surface temperature,which were analyzed respectively.