| In recent years, land use/cover-change of ecology fragile areas has become thefocus of people. Soil is an important factor of natural geography environment, whichis a complex, multi-layered open system. Soil degradation is one of the mainterrestrial ecological processes. This process will exhibit different characteristicsalong with land use, area and space combination. There is a strong correlationbetween land use and soil degradation. In this paper, the hilly area in Linyi city is thestudy area, including seven counties, namely Yinan, Yishui, Mengyin, Cangshan, Feicounty, Pingyi, and Junan. The data is based on the land use/cover type maps of1985and1995, and we used the image processing functions in Erdas9.2and the spatialanalysis module in ArcGis, which established the land use/cover classification map in2010and three land use/land cover database and transfer matrix of the years:1985,1995, and2010. The results indicated that the land use/cover dynamic characteristicsin the25years from1985to2010. Based on population, socio-economic statisticaldata, we studied the driving force of the Land use/cover by principal componentanalysis. Based on land use/cover change research findings and survey data, weanalyzed the characteristics of the soil degradation and the reasons under the land use/cover change. The results can provide a reference for the development and utilizationof land resources and soil conservation work in the hilly area of Linyi. The mainconclusions in paper are as follows:(1) Land use/cover dynamic change and driving forceArable land accounts for60%of the total area, is the main type in all types ofland, followed by the grass about18%. The construction land is the only type ofincreasing, and the amount of change is the largest. The decreased area ofcultivated land is the most. The increased area of construction land is mainly fromthe quality farmland. Comprehensive land use dynamic index of the study area was0.479percent, the land use/cover changes are not strong during the studyperiod. But land use degree index were more than270, significantly higher thanthe national average of231.92, indicating a greater intensity of land use. In theanalysis of the driving force of land use/cover change, we extract28indexesfrom all the35indexes by using principal component analysis, indicating that theindex selection are successful.28indicators can be roughly summed up to severalclasses: population growth, economic development, the improvement ofagricultural production technology, government policy.(2) Characteristics and causes of soil degradationThe main types of soil degradation in the study area are soil erosion. Theerosion area in Yishui and Mengyin county is the largest, followed by Pingyi andFeixian county. The erosion intensity is mainly moderate and erosion in2000s,mainly distributed in Yishui, Pingyi, Mengyin. In2007, the erosion intensity ismainly moderate and mild, mainly distributed in Feixian County, Mengyin, Pingyi,Yishui.The area of soil erosion showed a decreasing trend from1987to2007, andthe soil erosion intensity is also reducing overall. The strength extremely erosiongradually transformed into mild erosion from2000to2007.In the cultivated land and grassland, slope land and the land of low vegetationcoverage occupies the main position, lead to soil erosion widely distributed. Theincrease of the construction land in particular the urban construction land leads tothe soil degradation of city in physics and chemistry, and even affect the entireecosystem safety. This is mainly because of the surface closed hardening in thecity process. The irrational farming methods, such as excessive unscientificfertilization, pesticide spraying, plastic film and flood irrigation, cause soilpollution and soil salinization. This kind of pollution will be spread to theatmosphere and water. From the view of this point, the driving force of land use/cover change, in particular population growth and economic development, is alsothe cause of many types of soil degradation. |
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