Assessment On The Ecological Environment Vulnerability Based On Remote Sensing In Ebinur Lake Region

Presently, sustainable development is the highest aim of human beings, but population, resource and environment problems have become severe problems that human beings have faced. Rapid increasing of population and irrational using of resources has caused continuously decreasing in coordination ability of ecological system and weakening of human living condition. Through studying on ecological environment vulnerability, one of ecology's research contents, which would play crucial role in sustainable development of ecological environment vulnerable region. The ecosystem of Ebinur Lake region has been degraded, and its ecological environment is vulnerable. During western development period, realizing and assessing essence of Ebinur Lake region's ecological vulnerability, monitoring evolution of ecological environment and further restoration, this has great significance for sustainable development of Ebinur Lake region's environment and economy.This paper selected Ebinur Lake region as a typical research region, used modern ecology, geography, soil erosion theory and land resources sciences& methods as a direction, exerted spatial information technology, and chose multi-temporal (1990,2001 and 2007) Landsat TM/ETM+ remote sensing images have been chosen as a basic data source. We analyzed this region's landscape patterns and obtained landscape index, extracted research area's soil erosion and soil salinization information, at the same time built soil erosion and soil salinization sensitivity index model. Then we built Ebinur Lake region's comprehensive ecological vulnerability assessing model based on landscape index, soil erosion and soil salinization sensitivity index model, attained entire region's ecological environment vulnerability distribution map, and studied Ebinur Lake region's ecological vulnerability and its dynamic changing process. At last, we put forward the subarea restoration and protective countermeasure.Major conclusions: The research area was divided into 6 landscape patterns such as farmland, forest, grassland, water area, urban and rural construction land and unused land. Using dynamic degree model, landscape transition matrix, gravity center model and landscape index to analyze the landscape patterns of research area. The results showed that landscape patterns changed comparably in Ebinur Lake region. From the whole research period, following the rapid increasing of farmlands, urban and rural construction land, forests have increased at small scale, grasslands and water area decreased at different size. Moreover, soil desertification and soil salinization still should not be neglected. Transformation between the farmland, forest, unused land and grassland was relatively obvious, transformation between water area and unused land was more obvious. Entire moving trend of Landscape's gravity center was towards east. This was closely related to the expanding of artificial oasis and indicated moving direction of oasis gravity center. Most dominant contribution rate of changing-in was farm land and most dominant contribution rate of changing-out was unused land. It referred that with rapid development of economy; people modulated agricultural economy structure and reclaimed a mass of abandoned land. Separated degree of urban and rural construction land was very high, which indicated that its distribution was complex and its fragmentation was high. According to the PPU index, we found that in recent 20 years, the fragmentation degree decreased, contagion degree increased gradually and connectivity of dominant patch in landscape increased too. The SqP index value of urban and rural construction land increased, and the others decreased. This indicated that the complexity of patch in main oasis body decreased.We chose three landscape pattern indexes:Landscape Isolation Index, PPU index and SqP index, at the same time we used soil erosion sensitivity index and soil solinization sensitivity index to perfect the landscape ecology assessing of research area's ecological environment vulnerability. We built regional comprehensive ecological vulnerability model XEVI which based on ecological vulnerability index model of landscape type. It can reflect entire region's ecological environment vulnerability from spatial aspect. Assessment result showed that the gently vulnerable area spread far and wide, and it distributed in the inner oasis which consists of Botala city, Dlite town, Belinhamudun village, Jinghe County in the west of Ebinur Lake. Non-vulnerable and light vulnerable area mainly distributed around the Ebinur Lake, periphery of the research area and partly inside the oasis. Moderate vulnerable area mainly distributed in the unused land of inner oasis and periphery of the Ebinur Lake area. Serious vulnerable area has substantial effect to ecological environment changing of entire research area, distributed in the Nature Protection Area of Ebinur Lake, Mutar desert, between Ebinur Lake and Alashankou. In conclusion, from 1990 to 2007, the ecological environment of research area was relatively strong vulnerability, and its ecological degradation has already reached or exceeded the recent level of human beings' usage of resource and development of society, and some parts of research area's vulnerability degree were continuously intensifying. Besides, transformation between the ecological vulnerability was relatively frequent, not enough steady. In recent years, the transformation proportion of the moderate and serious vulnerability level was relatively big. This indicated that the ecological environment of research area developed from low vulnerability to high vulnerability and ecological environment was in the situation of continuously degrading.We put forward the restoration and protection countermeasure of research area ecological vulnerability for aiming at the current status of Ebinur Lake ecological vulnerability. To non-vulnerable area, we should intensify protection of Ebinur Lake area and alpine snow-ice covered areas, rationally use water resource, stabilize the lake area and forbid destroy alpine vegetation. To light vulnerable area, we must intensify the preventing the salinization of periphery of the Ebinur Lake area, spread Halophytes' seeds with man power to the dry lake shores, and it can alleviate gale's erosion of lake bottom. To general vulnerable area, we have to intensify rational using and management of water resource, land use should implement "water settling land" and "Conversion of cropland to forest and grassland", and stockbreeding also should implement "grass settling livestock". To moderate vulnerable area, together with restoration of destroyed vegetation in catchment's protection was intensified, cutting trees at random, reclamation, over-grazing should be forbidden, windbreak forests should be built. To serious vulnerable area, we should protect the present desert vegetation of Ebinur Lake catchment, forbid cutting trees and rebuild the destroyed vegetation. We should strictly control the carrying capacity, insure the normal growing and renewal natural desert vegetation which mostly contains haloxylon arnmodendron, and prevent the speed of desertification.