Study On The Dynamic Change Of Ebinur Lake Based On Multi-source Remote Sensing Data

Lake is an important node of information exchange and energy transmission in the ecosystem,It is also an indicator of the ecological changes in the atmosphere,biosphere,and lithosphere.Under the influence of global climate change,subtle climate change will cause sensitive fluctuations in the lake.Changes in the lake wetland directly affect the local ecological security,it can also reflect and reveal the influence of external environmental factors and human factors to the lake change,especially the change of lakes in arid areas will be more sensitive and more significant.Landsat data and MODIS data was used to explore the inter-annual and monthly variation characteristics of Ebinur Lake in this paper,at the same time using LLSI and center of gravity transfer trajectory further analysis the interference degree of Ebinur Lake by external factors,analysis of the fluctuation characteristics and intensity of the gravity center migration of Ebinur Lake area,finally,exploring the changing characteristics of related natural factors and human activities,using grey relational analysis to further explore the spatial-temporal dynamic changes and influencing factors of Ebinur Lake.The main conclusions of this paper are as follows:(1)Based on the construction principle of the traditional water index and water heat balance with TVDI characteristic space,depending on the unique reflectance characteristics of water bodies in remote sensing images,Based on the Temperature Vegetation Dryness Index(TVDI)and mechanism of constructing the traditional water index in this paper,to study the unique emissivity of water in remote sensing data,an automatic water index with 0 threshold segmentation line is proposed named Temperature Vegetation Water Index.Extracting water of Ebinur Lake by TVWI and verifying the precision with the traditional water index with high precision and good feasibility,at the same time,to extracting the water body of Alakol Lake,Bosten Lake,Poyang Lake which in different environment in order to explore the universality of TVWI,TVWI has high feasibility in the extraction of lake water.(2)Remote sensing monitoring of Ebinur Lake dynamic change based on Landsat data and MODIS data.First,Landsat data are used to analyze the inter-annual variability and dry and wet season variation characteristics of Ebinur Lake,the area of Ebinur Lake in May and September changed by-461.98 and-322.04km2 from 2004 to 2015;In addition,it was found that the shift of gravity center of Ebinur Lake was different in dry and wet season,but in the end evolved from northwest to southeast;Using MODIS data to analyze the monthly variation of Landsat data in Ebinur Lake as supplement.The inter-annual variation is similar to the results of Landsat,the monthly variation showed the trend of decreasing of the area of Ebinur Lake from May to October,the maximum change of the area of Ebinur Lake area reached-421km2;The LLSI of Ebinur lake in 2005 and 2010 is positive,it is showed negative from 2011 to 2015,it indicates that the external disturbance of Ebinur Lake is gradually enhanced;Based on MODIS data,the center of gravity transfer trajectory is similar to the evolution trend of Landsat data,in May,the center of gravity shift distance was larger in 2010-2011 and 2012-2013 years,and the transfer distance was 6.51,6.06 km,in September,the center of gravity shift was the largest in 2005-2008 years and the transfer distance was 8.4km,the transfer distance is only 0.96 km in 2008-2009/2010,through comparative analysis,it is found that the area difference of Ebinur Lake extracted from the two data sources is small,indicating that MODIS has better accuracy in extracting water information.(3)Based on the meteorological data and statistical yearbook data of the study area to analyze the factors affecting the dynamic change of Ebinur Lake from two aspects: natural factors and human activities,it is found that wind speed and temperature have negative effects on the area of Ebinur Lake,and the precipitation has a positive effect,in recent years,wind speed and temperature have increased in the study area,and precipitation has been decreasing.the influence of total population,cultivated land area and GDP on the change of Ebinur Lake area was explored in human activities,With the rapid development of economic and social development,the number of population is increasing rapidly.the area of farming area and water consumption is increasing gradually and the irrational allocation of water resources is more serious;Finally,the correlation coefficient of the area of Ebinur lake with related natural factors(evaporation,wind speed,precipitation,temperature)and human activity factors(total population,GDP)were analyzed by grey correlation,the order of correlation is evaporation volume,total population,wind speed,annual average temperature,annual average precipitation and GDP,the correlation coefficients were 0.81,0.79,0.78,0.75,0.74,0.6,respectively,it showed that evaporation,population and wind speed are the key factors affecting the change of Ebinur Lake area.The purpose of this article is to explore the sharp atrophy of Ebinur in spatiotemporal change,awakening people's awareness of the rational use of water resources and protection consciousness of sustainable development of lake resources in arid areas.Coordinating the contradiction between the social and economic development,ecological environment security and the rational utilization of water resources to provide scientific basis for the sustainable development and rational utilization of water resources in the Ebinur Lake area.