Anaylsis Of Ecological Security Of Sandy Area In Eastern Ningxia

This paper evaluated the ecological security of Yanchi county from the aspects of land use/cover change and its ecological effects, ecological footprint, agricultural economic environment and ecological environment coupling, and analyzed the ecological security based on PSR model analysis, and studied on ecological security warning using the RBF neural network method. The main conclusions are as follows.(1) Land Use/Cover Change (LUCC) is one of the important causes of regional environmental change. The analysis of LUCC of Yanchi County in1985,1996,2000and2010shows, grassland, farmland and sand are the main land use types in Yanchi, and land use types also mainly occurred between these three categories. From1985to1996, the acreage of arable land, sand, urban land and un-used land increased, while the area of woodland, grassland and water are reduced. From1996to2000, farmland increased rapidly and grassland decreased fast, woodland and water area increased, sand and un-used land area decreased. From2000to2010, the acreage of arable land decreased for the first time, while woodland, grassland and urban land increased fast, sandy area has also been greatly reduced; and the desertification phenomenon has also been effectively governed. Analysis based on LUCC landscape pattern and ecosystem service value showed that the Reforestation Project and Grazing Enclosure Project implemented in2000had played a positive role in restoring the ecological environment of Yanchi. Although the total ecosystem services value didn’t change much, but the ecosystem services value of different land use types changed significantly, as a result, the county’s overall ecological environment improved—grassland and forest area increased, while arable land reduced. Land use driving forces analysis showed that the causing factors of land use change in Yanchi County can be summarized as three categories:agricultural economic development, secondary industry and demographic factor. But the primary industry output, per capita net income of farmers, total power of agricultural machinery, animal husbandry output, rural electricity consumption, tertiary industry, agricultural output, crop acreage, second industry output, rural laborers forces, forestry output value, fixed asset investment, population growth and urbanization rate can also have impacts on the changes of land use types in Yanchi County.(2) Ecological footprint (EF) can effectively measure the degree of regional sustainable development, which is also an effective method to evaluate regional ecological security. Analysis based on ecological footprint of Yanchi showed that the total ecological footprint of Yanchi changed significantly, and the total ecological capacity didn’t change much, the total ecological deficit continued a downward trend. Since2005, the total ecological deficit becomes negative, which is mainly caused by changes in the total ecological footprint. Fossil energy land, grassland and arable land occupies a great proportion of the total ecological footprint in Yanchi County. The Per capita ecological footprint of Yanchi showed an increasing trend from1995to2012, while the per capita ecological capacity decreased, and the per capita ecological deficit increased year by year. Arable land, grassland and fossil fuels land account for a large proportion of per capita ecological footprint. And arable land and grassland account for a large proportion from the point of per capita ecological capacity. From the aspect of10,000Yuan GDP ecological footprint and10,000Yuan GDP ecological surpluses,10,000Yuan GDP ecological footprint of Yanchi County showed a downward trend from1995, indicating that the utilization efficiency of energy resources in Yanchi County is gradually improving. From1995to2003,10,000Yuan GDP ecological deficit of Yanchi County showed surplus. After2004,10,000Yuan GDP ecological deficit of Yanchi County showed deficit, indicating that the economic growth of Yanchi has exceeded the ecological capacity. Ecological Footprint Diversity and Ulanowicz Capacity Development analysis showed in the case of ecological diversity decrease, the development of Yanchi’s ecosystems economic development capacity mainly relied on the growth in ecological footprint demand. The reduction in the ecological footprint diversity index can not explain the changes in the ecological environment in recent years. All the above mentioned indicated, current social and economic development in Yanchi County are unsustainable and at the expense of the environment. To further analyzed the reasons that impact Yanchi’s ecological footprint, this paper used Partial Least-Squares Regression (PLS) to study the factors that affecting the ecological footprint, which showed that population, per capita living expenditure of peasant, the first industry output value, the third industry output value and urbanization rate are the main factors influencing ecological footprint of Yanchi County.(3) Agricultural Economics and Ecological Environment Coupling study is one of the research areas of sustainable development. Yanchi County is an important agricultural county in Ningxia, and agricultural production has a very clear ecological impact. Agricultural economy and ecological environment coupling analysis showed that the agricultural economy and ecological conditions continued to recover, and agricultural eco-economic coordination degree are on the rise, but the contradiction between agricultural economic development and ecological environment is very prominent. In order to further study on the relationship between agricultural economic development and ecological environment, this paper selected grassland which have significant meanings to Yanchi’s ecological environment construction, using STIRPAT model to analyze the factors that affecting grassland area. The results showed that population growth is the main cause of grassland acreage decrease in Yanchi County. Also there may be a similar to Kuznets curve between grassland area and GDP per capita, indicating Yanchi’s economic development played an active role in environmental governance. Dynamic analysis of factors that affecting Yanchi’s agricultural economic development by using VAR model, co-integration analysis, impulse response function and variance decomposition and other methods showed there is a long-term equilibrium relationship between the first industry and rural labor, livestock and chemical fertilizer, animal husbandry and agricultural economy positively correlated, animal husbandry made great contribution to the local economy, which was also one of the industries that Yanchi County should focus on the development in the future. Chemical fertilizer positively correlated with Yanchi’s agricultural economic development, but such influence is unstable, and the contribution to Yanchi County’s economic development is also not significant, therefore Yanchi County should improve agricultural productivity in the future. There is negative correlation between agricultural population and agricultural economy, agricultural population didn’t make contribution to the local agricultural economy, to some extent also inhibit the development of agricultural economy, and therefore Yanchi County should accelerate the development of secondary and tertiary industries, and transfer the labor surplus from agriculture to secondary and tertiary industries.(4) Social-economic-natural complex ecosystem included natural ecological security, economic and ecological security and social ecological security. Its ecological security evaluation index system is a comprehensive evaluation system consisting of multiple factors, for which we use the PSR model to construct the ecological security evaluation system for Yanchi County. The results showed that the security pressure subsystem of Yanchi fluctuated as a downward trend, which from1995to2007is in a "heavy warning" state; from2008to2012in the "humongous warning" state, and the subsystems fluctuated as a upward trend. The total ecological security warning indicators is on the rise, warning degrees shifted from "heavy" to "moderate", which, from1995to2006, the ecological security warning index showed an increase in volatility, but its warning degree is still "heavy"; from2008to2012, the ecological security warning index rose rapidly, and the index is greater than0.2,"moderate" degree, which is closely related to the implementation of Reforestation Project and Grazing Enclosure Project, the economic restructuring, as well as improving in people’s ecological concepts. In order to further analyze the impact of ecological security mechanisms of Yanchi County, this paper use Grey Relational Analysis method to study, the factors that affecting the ecological security, the results showed that fertilizer applicable strength, population density, population, desertification proportion of the area, the proportion of animal husbandry, agricultural population proportion, per capita arable land, agricultural production and the proportion of agricultural administration supports in the fiscal expenditure and other factors are the main factors affecting the ecological security index. Prediction on the Yanchi ecological security index by using grey RBF neural network showed that the ecological security index of Yanchi will continue to improve, but still with very heavy environment pressure.