Landscape Ecological Safety Dynamic Evaluation In Manas River Valley Oasis

Human activities are the main factors leading to the change of land use and cover,and also are the core driving force of the dynamic changes of the ecological environment in Arid Areas.With the acceleration of industrialization and urbanization,the types and structure of land use in oasis have changed fundamentally,and the scale and intensity of the change have accelerated,constantly,and the process and pattern are more complex,which leads to the composition,structure,function and the problem of ecological security in inland river basin have become serious,increasingly.Exploring and maintaining the stability and safety of oasis landscape ecosystem are an important task of oasis use planning and management in the new period.The Manful River Basin is the largest artificial oasis in Xinjing province after the founding of the People's Republic of China,and the problems of spatial expansion process and related ecological environment have been the focus of academia and government.In this study,the changes of land use and landscape pattern in Manful River Basin were studied,according to the theory of landscape ecology,based on remote sensing information identification and GIS spatial analysis technology platform,and used landscape index calculation method and Geo statistical analysis method,and used the three remote sensing images in the year of 1994,2005 and 2015 as the based data.On the basis of extracting land use type,structure and its dynamic change information,studying on landscape ecological pattern and its spatial and temporal variation characteristics and laws;Then from three aspects of ecological carrying capacity,ecological stress and ecological adaptability,building 5km * 5km evaluation unit and evaluation index system.The spatial interpolation of landscape ecological security index was completed by Archaist statistical module,and the spatial and temporal distribution of landscape ecological security was obtained.Analying the temporal and spatial variation characteristics and laws of landscape ecological security.Finally,studying The spatial correlation and heterogeneity of landscape ecological security by using Geode exploratory spatial analysis,and evaluating dynamic change of ecological security of oasis in Manful River Basin.The main conclusions are as follows:(1)During the period of 1994-2015,the area of cultivated land and construction land increased in Ma River Basin.It is mainly distributed in the transition zone between oasis and mountain or oasis and desert,which belong to agriculture and animal husbandry area whose economy was backward.In these areas,mainly rely on the expansion of arable land to met the extensive growth of the economy,its expansion rate slowed down but the ecological security risks.New construction land was mainly distributed in Sheepish,Manful,desert Bay counties and other surrounding areas of the city,With the trend of continuous expansion and the speed of expansion was accelerating,but the problem of ecological security had not been paid enough attention.(2)The change of landscape pattern index was not balanced,landscape diversity had decreased andheterogeneity had increased.The results showed that the irregular shape,complexity,heterogeneity of patches had increased in external,and decreased internal.Landscape diversity decreased in Oasis,corridor complexity increased and artificial oasis were stability,However,the landscape diversity and corridor complexity of oasis periphery were decreasing,which weakened the stability of natural oasis landscape.The change of the oasis in the middle of the river basin was obviously larger than that in the southern mountain area and the northern Oasis Desert Transition Zone.(3)The ecological security degree of oasis landscape in Ma River Basin tends to gather and tend to decrease in space.The distribution of "cold points" and "hot points" in study area showed that the intensity of human activities and ecological security spatial agglomeration degree were highly consistent.In the middle reaches of the basin,the ecological security of the oasis is much lower than that of the upper and lower reaches,which showed that the application of water-saving irrigation technology and the acceleration of urbanization process had not been able to curb the trend of ecological security degradation.So artificial oasis expansion and landscape heterogeneity were the main factors affecting the landscape ecological security,the potential impact of the new industrialization and urbanization on the landscape ecological security and pattern stability of inland river basins in Arid Areas should be paid attention to.