| Vegetation is an important part of terrestrial ecosystem and the centrum of the materialcirculation and energy flow in ecosystem. It devotes an important contribution to humansocial and economic activities. Vegetation shows the status of the ecological environment inarid and semi-arid areas. Vegetation status is connected with soil moisture and groundwaterlevel. The research on the relationship between vegetation growth and groundwater in aridarea has great significance on the rational use of water resources and improvement of theregional ecological environment. Quantitative description on the relationship between plantgrowth and groundwater depth in arid regions can provide foundation of science not only forthe sustainable maintenance of the vegetation ecosystems, but also for the restoration andregeneration of the degraded vegetation ecosystem. Therefore it will providedecision-making basis for achieving the coordinated and sustainable development ofeconomic, social and ecological environment in the arid areas of our country. Remotesensing data have been used widely in large-scale ecological environment research in recentyears with the development of remote sensing technology. The interaction betweengroundwater and vegetation can be studied quantitatively on macroscopic scale by usingcombination of remote sensing and groundwater information.West Liao River Basin is located in the east edge of west part of Northeast Plain which isacetones of farmland and pasture. It is a sensitive area of global climate change, and also oneof the key areas of national western development strategy implementation. Firstly, thedynamic type of groundwater in research area will be determined in this paper by statisticand evaluation on meteorological, hydrological, groundwater depth etc. data. The dynamictype of groundwater will be divided into four types, including precipitation infiltration,precipitation infiltration mining, precipitation infiltration and evaporation, and precipitationinfiltration runoff according to the actual situation. Then, the further research on therelationship between vegetation coverage and groundwater depth in West Liao River Plainwill be completed by mathematical and statistical methods, GIS spatial analysis techniquescombining with remote sensing data. The following conclusions will be achieved through the research.(1) The groundwater depth of West Liao River Plain is affected significantly by artificialexploitation. The evident groundwater drawdown funnel has appeared on regions where thegroundwater is concentrative exploited,such as Horqin District of Tongliao City, HorqinZuoyi Hou Banner and middle area of Naiman Banner in Inner Mongolian AutonomousRegion.(2) The vegetation information of West Liao River Basin will be extracted based on themacroscopic and microscopic scale by using GIS and RS technology, and Landsat-5 images(TM,ETM+ images)in 1989, 1994, 1999, 2006 and 2010.The vegetation index and supervised classification methods will be used for informationextraction in the macroscopic scale. The change of vegetation coverage of West Liao Riverin above five periods will be analyzed by Normalized Difference Vegetation Index (NDVI)method. The analysis shows that 100m is the most suitable elevation value for vegetationgrowth. The change of average vegetation coverage rate of West Liao River Basin in the fiveperiods is 1989>2010>2006>1999>1994. The actual change conclusion of arable land,grassland and woodland will be obtained by using maximum likelihood method of thesupervised classification. The conlusion is that the arable land and grassland area isincreasing and the overall trend of the woodland is reducing from 1989 to 2010.The grassland will be further divided into two types, including partial drought and partialwet based on the methods of analyzing specific samples and utilizing the vegetation spectralinformation collected from fieldwork in the microscopic scale part,. The result shows partialdrought grass area is larger obviously than the partial wet grass area in the research region,and the classification accuracy is also better than the supervised classification.(3) The vegetation coverage is affected by the types of terrain in research region. Generally,the vegetation coverage is good in the flat terrain, such as slight undulate plain, flood plainand loess tableland. The vegetation coverage is decreased in arid area and the area with poorgroundwater supplement, such as sand dunes, sand ground, and the slope of alluvial fan, etc.(4) The vegetation coverage is affected significantly by precipitation in research region.Specially, the clear positive correlation will be obtained in the sandy area. The correlationcoefficient is 0.76. The vegetation coverage is better with more rainfall.(5) There is a kind of response relationship between the groundwater depth in research areaand the vegetation ecosystem. In the grassland of West Liao River Plain, the vegetation coverage will be affected significantly when the average depth of groundwater is less than4m; the condition is suitable for the vegetation growth when the vegetation depth is between0.5 and 2.7; the depth of the groundwater will not be the most important affecting factor forthe vegetation of grassland when the depth of groundwater is more than 4m.The innovative points of the paper are as follows.(1) The further research on the relationship between vegetation coverage rate and thegroundwater depth will be compeleted by utilizing GIS spatial analysis technology.(2) The vegetation evolutionary tendency of research region will be predicted and analyzedfor the first time by using the combination method of mathematical statistics and GIS spatialanalysis techniques based on the analysis on relationship between dynamic groundwater andthe macroscopic change response of vegetation in West Liao River Plain.
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