Based On The Landscape Pattern Of Northern Tarim Basin Oasis Ecology Security Studies

The northern margin of the Tarim Basin oasis is located in the arid zone of northwestern China,the area characterized by dry climate,limited water resources and fragile ecological environment.As the core part of Silk Road economic belt,maintaining the ecological security is the basic fundamentals to keep regional sustainable development,and building a scientific and rational pattern of oasis ecological security is particularly important.In this study,Ugan-Kuqa river oasis was selected as the research target,three remote sensing images in 1997,2006 and 2016 were used as the basic data,the ecological principles and methods were combined to adapt the landscape pattern index,and analyzed the landscape pattern characteristics of Ugan-Kuqa river oasis from 1997 to 2016.The landscape structure index was utilized to build landscape ecological safety assessment model,and the temporal and spatial characteristic of oasis landscape in the past 20 years was analyzed.The minimum cumulative resistance(MCR)model were applied to build oasis ecological security pattern taking large area of space continuity and plaque waters and forest land as the “source”,and ecological security level,elevation and slope as resistance factor to generate resistance surface.The ecological function area,corridors and nodes was identified.In order to provide countermeasures and suggestions for the sustainable development of oasis ecological security,the oasis ecological security pattern was established from the point,line and surface.The main conclusions of this paper are as follows:(1)From 1997 to 2016,the farmland,forest and grassland,saline alkali land and other unused land patch areas are the main landscapes in Ugan-Kuqa river oasis;the oasis landscape consists of various from simplification to complexity.agglomeration of trends between various types of landscape continue to strengthen,probability between adjacent landscape types is rising,the connectivity of different landscape types is decreasing in fluctuation,the diversity of the various types of landscape decreased but the overall distribution is uniform.(2)From 1997 to 2016,four types of landscapes,such as unused land,cultivated land,forest and grassland,and saline alkali land were the main part of the oasis land use transfer mode.The land conversion between different land use types in the oasis area was mostly concentrated in the edge area of the Ugan-Kuqa river oasis.The changing rates of cultivated land and other unused land area was larger;the area of urban land,cultivated land and other unused land changed greatly;the area of cultivated land and urban land use was increased;the changing rates of water,saline alkali land and forest grassland was relatively weak.(3)From 1997 to 2016,the landscape ecological security situation of the Ugan-Kuqa river oasis is expanding from high to low.The areas with high safety was mainly cultivated land,forest grassland and water landscape,and presented increasing firstly and then decreasing trends.The local spatial autocorrelation of agglomeration was mainly higher aggregation and lower accumulation types;high accumulation area mainly distributed in the north and south parts of study area;lower value of concentrated areas was mainly distributed in the western and eastern regions of oasis.(4)The ecological sources of study area are mainly distributed in the north and south of the oasis,which is composed of water and forest grass,accounting for 12.76% of the total oasis area.The network of oasis ecological corridor runs through the whole research area.The ecological node is mainly distributed in the most vulnerable parts of oasis ecological corridor.According to the spatial distribution of minimum resistance values,the oasis is divided into four zones,including ecological buffer zone,ecological connected zone,ecological transition zone and ecological marginal zone.The optimized ecological security network of oasis landscape combines ecological source,ecological corridor,ecological node and ecological function area,and puts forward the construction strategy,in order to provide scientific basis for further improving the oasis ecological environment.