Study On Land Use Change And Its Influence On Land Ecological Security In Wushan County

With the rapid economic development, rapid population increase, and constantly enhance the extent of human landuse and transformation of land resources, people and landhas become increasingly acute contradictions, continued degradation of the ecological environment, Increasingly serious food security issues.These problems are a major problem gave rise to pressure and threats to humans. Thus, taking advantage of regional land use change and grasping the direction of change and trends is very important. Land use is an important factor affecting soil quality, biogeochemical cycle, regional climate characteristics, water resources and natural disasters. land use intensity enhancement has led to ever-changing ecosystem, along with global environmental problems. At the same time, Increasing pressure on land in the process of urbanization. Land ecological and environmental problems of soil erosion, desertification, land contamination threat to regional land ecological security and even affect the sustainable human development. Three Gorges reservoir area is the National Ecological and environmentally fragile areas and the country’s major ecologically sensitive economic zone.Three Gorges reservoir area with the proble of that Large population and scarcity of land,high mountains and steep slopes, economic backwardness, the obvious contradiction between people and land.Some studies have pointed out that the Three Gorges Reservoir Area of land use change is the direct cause of degradation of the ecological environment of the region. This paper selects Wushan County as a research object. This article studies the Wushan County land-use change and the impact of land use change on land ecological security.The content and structure of the paper is summarized as follows:Chapterl:Introduction.This section mainly discusses the background, the significance, literature review, the objectives, the content, ideas, the research methods.Chapter2:study area and the underlying data. Described the study area and data sources and processing.Chapter3:Wushan County in 1997—2008 land-use change. This paper analyzes the land use change in Wushan County from five aspects:land-use change amplitude, single land use dynamics, land use degree change, the landscape diversity and dominance index of land use change. The analysis show that during the 12-year,woodland growth plus 11651.23 ha, Arable land total reduction of 13567.70 ha. From land use dynamics point of view, the degree of change of water conservancy facilities and the garden is the most dramatic and dynamic degree of 1130.49% and 33.88%. From landscape diversity index point of view, the overall growing trend, in 2005 the maximum 1.9117,2003 reached the lowest value of 1.8275. From the advantage of view, as a whole showed a decreasing trend, in 2003 reached the maximum is 0.4751,in 2005 minimum is 0.3923.Chapter4:Land-use change impact analysis of land ecological security assessment. The analysis of the impact assessment of land use change on land ecological environment and land use change on land ecological security.The impact of land use change on land ecological security. In this paper, Selected climate, hydrology, soils, geological disasters to analyze the impact of land use change on land ecological security.1997-2008 period, the Three Gorges Project makes the Three Gorges reservoir arealand use and Land structure changed greatly. Analysis showed that the temperature has increased,precipitation has reduced in the Three Gorges reservoir from 1997-2008. The used amount of chemical fertilizer and pesticide use quantity increases, affected the water quality of Yangtze River.Land use intensity increases, Wushan soil erosion rate increased. Land use intensity resulted the growth of soil and water loss in Wushan county. Land use intensity increased and the impact of the Three Gorges project, which makes the earthquake, collapse, landslide, landslides and other geological disasters increase.Land ecological security assessment in Wushan County. In this paper, land ecological security assessment using the PSR conceptual framework model and establish the pressure on land resources, the status of land resources, land resources to respond to the indicator system. The article in accordance with the requirements of the analytic hierarchy process to build the target layer, rule layer, status layer and variable layer, identified 20 evaluation. Entropy method to determine the index weight, calculate the ecological security value of the index from 1997 to 2008. Overall, the 12-year period of 1997-2008 the land ecological security value increased from 0.4662 to 0.4704, in 2004 reached the minimum 0.4609,in 2002 years is maximum value of 0.500.Wushan County land ecological security values in theⅣsecurity level, indicating that the Wushan County land ecological environment has been more serious damage to the system structure and function by a greater degree of loss, land recovery and reconstruction difficult. The values of pressure on the land security generally decreasing, decreased to 0.1406 from 0.1489 during 12 years, and in 2008 year reaches a minimum value of 0.1406.These numbers indicat that the land of Wushan County is under increasing pressure. The security value of the land status indicators showing a declining trend. Security value of land status from 1997 to 2008 decreased from 0.1579 to 0.1329. The security value in 1998 reached the maximum 0.1581,in 2006 reached the minimum value 0.1296.The status of that land ecosystem is deteriorating. Security value of the land response indicators showing the increasing trend. Security value of the land response increaseed from 0.1595 to 0.1969,a total increase of the 0.0374, an average increase of 0.0031. These showed that humans achieve greater success in improving the land ecological security.Chapter5:Conclusions, discussions and outlook. This part summarizes the conclusion of this study, discusses the deficiencies of this paper, and points out the future forecast to future research.