| The ecological environment question is one of the important issues faced together inthe 21st century. Author participate in the project of Natural Science Foundation of China"the geochemistry mechanism of saline-alkali soil's development and early warningresearch of desertification in the west of Jilin Pronvince"and Jilin provincial scientific andtechnological commission key research projects "The ecological environment with repairtechnical research synthetically in the west of Jilin Province " and " The preventmentand cure studying of alkalization desertified land utilize in the west of Jilin Province " andso on,finding under nature and human factor acting on together, the ecological balance inthe west of Jilin is destroyed in the past 50 years, the ecological environment isworsenning constantly, ecological function fail day by day , produce salt and alkaline landincrease , grassland degradate , water areas and wetland atrophy and other series ofecological environment problems appear, At present, the west of Jilin Province becomeone of places which the ecological environment is the most fragile and the destroymentis the most serious .Changling county lies in the west of Jilin Province, it is strongly influenced bymonsoon, the rainfall is small, evaporation capacity is great, according to statistical data,there is a trend that the climate of this district turns to the aridity, the climate aridity hasaggravated the development of the salinization of soil of the land.Other meadow resourceof this district is relatively more abundant , but because of the influence of the humanactivity, that caused a large number of meadows degradateting, aggravated the landdesertification and salinization of soil. So the ecological environment question ofChangling county has model nature and representativeness in the whole west of JilinProvince and the decreas of its ecological environmental quality is also one of the factorswhich cause the whole environmental quality drops in the west of Jilin Province.In order to understand on the chang of the whole ecological environmental quality ofChangling, this text uses the analytic approach of the level at first, and two data(statisticdata and remote sensing) combine together to evaluate the ecological environmentalquality in 1989 and 2001 separately ,such as Changling appraise respectively by remotesensing. It can be found that the ecological environmental quality of 28 villages and townspresent the downward trend in 31 villages and towns of Changling county during 1989 and2001, and the villages and towns which ecological environmental quality drop mostly liein central and west regions of Changling.The land is the foundation that the mankind depends on for existence, at the sametime the land utilization and variation tendency is the comprehensive form of expressionof the regional state of ecological environment,so the variation of the land utilization isone of the main factors causing the decease of Changling's ecological environment.This text uses RS-GIS integrated technology to carry on the remote sensing interpretationof the land utilization of Changling county in 1989 and 2001 , and make a detailedanalysis to the dynamic change of land utilization of Changling county from quantity andspace pattern change of this two period.It can be found from the result that on thequantity,the main landtype of Changling appears "two increases and three decrease"."twoincrease"means cultivated land and salt and alkaline land increase(salt and alkaline landincrease very fast),"three decrease"means the decease of meadow, water andwetland(wetland decease very fast).Analyzing from space pattern, the view structure of alllandtype has changed too, brokenness degree is reduced in such places as salt and alkalineland , the border form of the spot one tends to simplify , regular and develop towardsdirection that concentrates on in flakes; but brokenness degree of meadow, water areas,wetland,etc increase, its border form of piece become more and more complicated,irregular and disperse to any direction .According to the study of change of the land type in Changling county, it can befound that the constant increase of a large amount of salt and alkaline land and thedecrease of the meadow are another main factors which causes ecological environmentdeterioration of Changling, so only to understand the variation and reason that someonecan take some measures to control the increase salt and alkaline land and reduction ofmeadow .The dynamic change carrying on the meadow and salt and alkaline land on thebasis of the above-mentioned reasons this text studies.Result indicate the newly-increasedsalt and alkaline land of Changling stem from medium covered meadow,low coveredmeadow, water areas , beach and wetland during 1989 and 2001.The area of the landwhich transform into salt and alkaline land account the area of the newly-increased saltand alkaline land separately is 16.61%,54.63%,8.31%,12.46%,and 7.99%.It is obvious ,the meadows and water bodies are main sources of the salt and alkaline land. That indicate...
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