Changling County Land Use Change On Regional Ecological Environment Impact Studies

As one of the core projects of global change research, the study of land use/land cover change has attracted the cosmopolitan interest related to the consanguineous interactions between nature and human being. Land use/land cover change, which is the important influential factor to the environment on the ground, is the main cause of the global and regional environment change. As a result, how to understand the impact of land use/land cover change to regional ecological environment is the key problem for realizing the sustainable development of region. The county of Changling, located in the eastern edge of Songnen Sands, is a typical ecotone between agriculture and husbandry in northern China. In the viewpoint of land use/land cover change, it is an ideal district for research. In this thesis, we make use of the remote sensed data, the land use map, statistical data such as soil general data and field-measured data to analyze the land use change of Changling County of the latest 20 years between 1981 and 2000 under the support of GIS, and further we make some preliminary study on the impacts of land use change to regional climate and soil conditions. The most importance of the study is to support the foundation for the county of Changling to formulate the policy of land use optimization. The whole thesis is made up of six chapters described as follows:In the first chapter, we make a brief review on the impact of land use/land cover change on regional ecological environment, the research situation in this field as well as the shortcoming of the present research. And then, the significance and objective of this study is brought forward.In the second chapter, we make a brief introduction on the geographical environment of the county of Changling. In the third chapter, we analyze the extent, rate and the spatial change of land use supported by the interpretation of remote sensed data and the functions of data input,IV___________________________________Abstract__________________________________edit, spatial analysis and statistics of GIS. We summarize our results as follow: during the period of 1981-2000, there was a great change of land use in the county. The area of arable land, forest and saline-alkali land increased; water land and resident land changed a little; the area of the grassland and wasteland decreased greatly. The increment of population and the change of agricultural structure are the indirect cause of the change of land use.In the fourth chapter, we further clarify the relation between land use/land cover change and regional climate change, i.e. temperature and precipitation in Changling County. As a representative region in the ecotone between agriculture and husbandry in northern China, the reduction in vegetation cover in Changling County increases both the surface water flow and surface temperature. As a consequence, from 1981 to 2000, the county was in the stable temperature increasing but precipitation decreasing period. The research also indicates that the deterioration of regional ecological environment induced by land use change should be responsible for the frequent sand-dust storm in the recent time.The fifth chapter focuses on the impact of land use on the regional soil conditions. During the study period, the soil nutrient of arable land and grassland reduced greatly and that of forestland changed slightly. The grassland has the highest soil nutrient, while the arable land has the lowest soil nutrient. As a consequence, the land use change in Changling County in the past two decades leads to decrease in the net soil nutrient, as well as the deterioration of regional ecological environment..As a perspective of this thesis, we further discuss the relationship between precision farming and optimization of land use in the sixth chapter. On the basis of our research, we clarify the necessity to systemize and informationalize land use.