| Land use/cover change is an important part of global environmental change.The evolution of land use patterns can not only directly change the surface cover,but also affect and affect the structure and function of various ecosystems to a certain extent.Changes in land use patterns may cause a series of ecological and environmental effects,and research on ecological vulnerability has attracted more and more scholars’attention.The oasis on the northern slope of the Tianshan Mountains is the core area of Xinjiang’s economic development.It reveals the evolution of oasis land use patterns and its ecological and environmental effects,and clarifies the temporal and spatial differentiation characteristics of ecological vulnerability.Provide scientific reference for scientific management and protection of regional ecological environment.This study takes the oasis on the northern slope of the Tianshan Mountains as the research object,and analyzes the temporal and spatial characteristics of land use patterns in the oasis of the Tianshan Beibo oasis in 1975,1990,2005,and 2018 with the help of RS and GIS.Vulnerability assessment.The main conclusions are as follows:(1)The overall pattern of land use of the oasis on the northern slope of the Tianshan Mountains is as follows:cultivated land,grassland,and unused land are the dominant land use types in the economic belt on the northern slope of the Tianshan Mountains,occupying a large proportion of the area,and other land use types have smaller areas.From 1975 to 2018,the land use/cover of the oasis on the northern slope of the Tianshan Mountain changed significantly.From the perspective of time series changes,the area of cultivated land and construction land has been increasing,the change of grassland and unused land has gradually decreased,and the area of forest land and water areas has increased first and then decreased;cultivated land,forest land,water areas,construction land The growth rate was 0.58%,0.12%,0.20%,and 3.29%,while the grassland and unused land decreased at 0.13%and 0.11%,respectively.From the perspective of spatial changes,from 1975 to 2018,the land use/cover types of the northern slope of the Tianshan Mountains all changed to varying degrees.The largest increase in construction land area was mainly the transfer of cultivated land and unused land.The use of land transfer in,the largest reduction of grassland transfer is mainly arable land.At the landscape level,the number of patches in the study area increased year by year,the degree of fragmentation increased,the diversity index showed an increasing trend,and the spread index continued to decrease.(2)Based on the natural environment,ecosystem,and socio-economic characteristics of the oasis on the northern slope of the Tianshan Mountains,the"sensitivity-resilience-stress"concept model was selected to construct an ecological vulnerability assessment index system.The indicator system includes a target layer,a criterion layer,and an indicator layer.The indicator layer has a total of 15 factors.The AHP analytic method is used to calculate the indicator weights and perform consistency checks.Based on the remote sensing and GIS methods,each index was spatially quantified one by one,and the spatial data set of the index system was obtained.(3)Spatial-temporal differentiation of oasis ecological vulnerability on the northern slope of the Tianshan Mountains based on model-weighted calculations:The areas with higher levels of vulnerability in the study area are mainly distributed in densely populated or poor habitat areas in the central and eastern regions,while the lower levels of vulnerability A small area is distributed in areas that are less affected by human activities and have a good ecological environment.From the perspective of time changes,the overall ecological vulnerability has been decreasing and easing since1975-2018.The area of extremely vulnerable areas in 1975-2018 is reduced by58573.01km~2,which is slightly vulnerable.The increase in the area is up to17509.33km~2.From the perspective of spatial distribution,the original extremely ecologically fragile areas were transformed into low-and medium-level ecological fragility. |
