Study On The Drought Condition Based On The Comprehensive Drought Monitoring Index And Remote Sensing Evaporation In The Area Of MAO Wusu Sandy Land

system in this paper analyzes and summarizes the drought monitoring methods at home and abroad,and discusses the normalized NDDI drought index,the scale SMMI index,temperature vegetation drought index TVDI these three drought monitoring index in the abdominal region maowusu sandy land suitability of drought.On the basis of this combined with the land use data and meteorological data site data,through the analytic hierarchy process(ahp)to determine weight,build based on comprehensive drought monitoring index,and then using the field measured soil moisture data to verify this model,and determine the comprehensive drought monitoring index of drought grade division standard.Finally,the comprehensive drought index monitoring model is applied to analyze the situation of the dry condition of the middle part of mausu sand.Colleagues based on energy balance equation of SEBS evaporation model to estimate the daily evapotranspiration of the region,drought conditions in the region are analyzed,and compared with the results of the comprehensive drought index model analysis.The main contents and conclusions are as follows:(1)Use in April 2016(spring),September(autumn)two issue of remote sensing data of different vegetation coverage,calculated NDDI,scale SMMI and TVDI respectively with 0 ~ 10 cm,10 ~ 20 cm,20 ~ 30 cm soil depth,soil moisture content index model is established,the linear model,logarithm model and quadratic polynomial model,to determine a single monitoring index of quadratic polynomial model for optimal fitting function in this study.Meanwhile,the effect of NDDI method and SMMI method in monitoring soil moisture content fluctuates greatly with the change of time,and the stability of TVDI method in monitoring soil moisture content is relatively better.(2)In a single drought index based on the analysis of the adaptability and comprehensive NDDI,scale SMMI and TVDI,through the method of analytic hierarchy process(ahp)is assigned to different weight coefficient,three basic parameters to build the comprehensive index of drought monitoring model.Through field measured soil moisture content data to verify this model,the results show that the comprehensive drought monitoring index significantly correlation with field measured the moisture content is better than that of optimal single index TVDI correlation with moisture content of field survey,can better characterization of drought conditions.(3)For water effect contribution(Hi),in April and September,the comprehensive drought monitoring index effect of water body,cultivated land,woodland and grassland was over 7%.The global Moran index I of the comprehensive drought monitoring index was 0.71 and 0.83 respectively,and the z-values were respectively 48.44 and 57.39.This indicates that there is a certain positive correlation and spatial agglomeration in the regional distribution of comprehensive drought monitoring index in the abdomen of maowusu sandy land.(4)Based on energy balance equation of SEBS model to estimate the abdominal region-wushen banner maowusu sandy land in September 2016,4,6,8,4 data daily evaporation capacity,results showed that the evaporation area in north-central wushen banner is not small,reflecting the underlaying surface soil water shortage.At the same time,in the southern area of wushen banner,more water was added,reflecting the sufficient water supply on the underlying surface without drought.Secondly,from the data of the four phases of April,June,August and September 2016,it was found that evapotranspiration was positively correlated with DI,and R2 was greater than 0.5.