Ecological Security Assessment Of Desert Ecosystem Based On Ecological Security Index

Desert ecosystem is an essential component of terrestrial ecosystems, and it is also the foundation of development of natural environments and human society life. But due to its harsh natural environment, unitary ecological structure and vulnerable ecological security, desert ecosystem is susceptible to external forces with worse recovery. To promote our development in harmony with the natural ecological system in the context of sustainable development, it is necessary to make scientific evaluation on the ecological security of desert ecosystem which is the vital prerequisite for development and also the theoretical basis of regional social economic development and ecological building.Yanchi County of Ningxia Autonomous Region lies in the south side of Mu Us desert, which make windy desert region of North Yanchi County a typical desert region. The eco-environmental vulnerabilities coupled with the regional unreasonable human activities make the region with wind-sand disaster, land desertification, and grassland degradation. The paper selected sandy area of North Yanchi County as the study area and took regional ecological environment and human activities as the study object, aiming at ensuring the regional ecological security, meanwhile combining with ecological security theory and introduction to sciences of human settlements, consulting the research on ecological security index of forestry issued by the State Forestry Administration which established the index system on deserts, wetland and forests, established the index system of ecological security assessment for desert ecosystem in resources, services, drive, interference, resource consumption and maintenance according to the local soil characteristics. Using analytical hierarchy process (AHP) to determine the weight of each index and the comprehensive index to calculate the regional ecological security index, we proceeded regional ecological security assessment and dynamic analysis, and explored the dominant factors affecting regional ecological security, then studyed the regional ecological security mechanism. As the same time, it could provide reference for the rational allocation of resources, desertification, soil and water conservation and settlement pattern optimization. The main conclusions are as follows:1) According to the regional ecological security environment and the index system established by the State Forestry Administration on ecological security assessment of desert ecosystem, I constructed the ecological security assessment index system in the sandy area of Yanchi County from the characteristics of the natural environment and the influence of human activities on the natural environment tension respectively. The whole indicator system has two levels, in which there are 2 first grade indicators,6 second grade indicators and 12 single indicators. The first grade indicators can be classified into two indexes such as status indicators and stress indicators. And the second grade indicators can be classified into six indexes such as resources, ecological service values, resource consumption, stress, interference, maintenance capabilities.2) The results showed that ecological security indexes which are between 15 and 80, could be divided into five grades. The higher the level of ecological security index, the better the condition of ecological security. The townships ecological security indexes are between 42 and 58.3) On the basis of classification and data analysis, we calculated and compared the regional ecological security index between the yearof 2007 and 2014.We found that regional ecological security level, which is transforming from the low level to the high level, showed a rising trend. The township ecological security index had been improved in recent years, which was closely related to the regional ecological construction and protection measures.4) The ecological security index of the study area and the total mechanical power and rural electri-city consumption from regional agricultural production condition fetors showed a strong positive correla tion, and were also positively correlated with the per capita net income from human living environment factors. During 2007-2014, change of the ecological security index and the transfer of grassland, forest and sandy land were closely related, and the regional land use pattern had placed an important infiuenc-e on regional ecological security. Human social life system should coordinate with natural ecological sy-stem, and seek common development, especially for the desert ecological system which is rather fragile, reasonable coordination between human social life system and natural ecological system is critical to th e long-term regional ecological security.