| Desertification affects the health of the people of the world,which has become a common concern of the ecological problems.China is one of the most serious desertification countries in the world,the desertification has gone beyond the traditional desert area,and extend to the seven river basins in China.Liaohe River is one of the seven river basins,and the largest river in Liaoning Province,the land desertification in Liaohe River Basin is becoming more and more serious,and becoming the new source of Liaoning province,which is Seriously restricting the healthy development of ecological economy in Liaoning Province.This paper is based on the remote sensing data of Liaohe River Basin,the elevation data,soil erosion and other existing research data,based on field survey data collected,comprehensive evaluation index system,and classification value of evaluation index,using the analytic hierarchy process to calculate the index weight analysis.,dividing the degree of land desertification based on fuzzy identification,and combining Arcgis to divide different desertification degree areas,count the area and the area of desertification in the sandy area.The main research is as follows:(1)Interpreting Liaohe River Basin in the remote sensing image for land use and the elevation map,and Based on the results of field investigation,121 samples were set up.In the field survey,the data can be obtained directly,Determination and calculation of soil moisture,aggregates and other indicators can not be directly obtained data.Carroy out the data of the various indicators,and A comprehensive database for the study of desertification regionalization was established.(2)Refer to the existing Chinese and English literatures related to desertification evaluation,and the evaluation index system including 6 indexes,including biology,soil,vegetation,landform,climate and social economy is established,the weight of each index is calculated by the analytic hierarchy process,and get soil,organic matter,soil water stability,large aggregates,soil,fractal dimension,number,vegetation,coverage,soil erosion and land use types 6 participating indicators,and each index is divided into 4 grades.(3)Analyse the spatial analysis of evaluation index:the distribution of the 3 kinds of soil and vegetation coverage showed a trend of increasing from north to South and from west to East.The content of soil organic matter was higher than 4 g/kg in the eastern mountainous area and wetland area of the river basin,and the water stable aggregate was higher than 40.15%,the fractal dimension was higher than 2.5,and the vegetation coverage was higher than 50%;the content of soil organic matter in the central plain is between 2 g/kg-4.0 g/kg,and the water stable aggregate is 20.15%-40.15%,the fractal dimension is 2.3-2.5,and the vegetation coverage is 30%-50%;the content of soil organic matter in Northwest China is less than 2 g/kg,and the water stability is less than 20.15%,the fractal dimension is less than 2.3,the vegetation coverage is less than 40%,and some areas are less than 10%.Soil erosion is mainly distributed in the West and north of the basin,mainly in Shenyang and Fuxin.The effect of land use on soil fractal dimension was analyzed,the results show that the effects of different land use on fractal dimension are different,among them,the farmland was the biggest and the grassland was the smallest,fractal dimension can be used as an index to evaluate land desertification.(4)Desertification mainly occurred in Shenyang,Fuxin and Tieling the total area is about 3864,30km2,of which the area of mild desertification is 3249.73km2,the area of moderate desertification area iskm2,the area of severe desertification is 68.80km2,and the area of extremely heavy desertification is 16.03 km2.The distribution of land desertification was obtained,the wind erosion of farmland desertification area is mainly distributed in Zhangwu,Xinmin and Taian.The area of mild desertification in Zhangwu farmland is 730.32 km2,and the total area of desertification is 773.31km2,which mainly distributed in Shahe,two rivers,river and other rivers.Xinmin wind erosion of farmland moderate and severe desertification area of the largest,which were 130.02 km2 and 7.32 km2,total area of desertification is 274.56 km2,mainly distributed in the Liaohe River,Liuhe and Raoyang River.Taian extremely severe wind erosion of farmland desertification area is the largest,is 5.41 km2,total area of desertification is 103.50 km2,mainly distributed in Liaoning around the canal and small Liuhe Strait.The desertification area is mainly distributed in Zhangwu and Xinmin.The largest area of light sandy land in Zhangwu is 128.86 km2,and the total area of desertification is 149.34km2,the main distribution on both sides of Toudaohe River,across the river and other rivers.Xinmin forest wind erosion in moderate and severe desertification area is the largest,respectively 21.73 km2 and 5.22 km2,the total desertification area of 118.76km2,mainly distributed in the Liaohe River,Liuhe and Raoyang River.The Wind Erosion Desertification Grassland is mainly distributed in Zhangwu,a total area of 242.56 km2,the wind light and moderate desertification grassland area is the largest,respectively 186.76 km2 and 55.02 km2,mainly distributed in the Weitang River,on both sides of the two river and other rivers.(5)Water erosion of farmland desertification area is mainly distributed in Fuxin,total area of desertification is 503.93km2,the farmland water erosion in mild and moderate severe and extremely severe desertification area were maximum,were 423.42km2,64.30km2,11.72km2 and 4.49km2,mainly distributed in the Raoyang River,and Beijing River,Ying River and two harrier Road on both sides of the river.The Water Erosion Desertification woodland area is mainly distributed in Fuxin and Fuxin Faku,woodland erosion mild,severe and extremely severe desertification area,were 95.72km2,3.52km2 and 0.41km2,the total desertification area of 115.10km2,mainly distributed on both sides of Raoyang River,river and other rivers and beijing.Water erosion moderate desertification area Faku forest,desertification is 20.02km2,a total area of 27.88km2,mainly distributed on both sides in the Xinkai River and the old horse river and other rivers.Fuxin water erosion of grassland desertification area is mainly distributed in Fuxin,total area of desertification is 105.24km2,mild,moderate,severe and extremely severe desertification area were maximum,were 54.26km2,39.53km2,10.17km2 and 1.28km2,mainly distributed in the Raoyang River and the Beijing River and other rivers and two banks.There are different degrees of desertification in different river basins,which provide guidance for the study on the mechanism of desertification and the restoration of vegetation. |
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