基于多时相遥感数据的乌鲁木齐市生态安全格局构建

Construction of ecological security pattern in Urumqi based on multi-temporal remote sensing data

构建生态安全格局可促进区域生态发展,对于生态脆弱区的环境改善显得尤为重要。以乌鲁木齐市2000、2010年和2020年3期土地利用数据为基础,通过生态系统服务重要性和生态敏感性评价识别了生态源地,借助最小累积阻力(MCR)模型提取了生态廊道,利用电路理论确定了生态夹点,最终采用阻力阈值法构建了生态安全空间并明确了高警戒修复区。结果表明:(1)近20 a,生态源地面积呈增加趋势,共计445.63 km^(2),占比增加3.19%,新增生态源地主要分布于研究区西南和东部的乌鲁木齐县和达坂城区。(2)识别3期生态廊道总数分别为27条、30条和40条,总长度分别为870.42 km、1115.83 km和1277.12 km。(3)近20 a,研究区5个等级生态安全空间分布具有不均衡性。高生态安全空间集中分布于研究区东北部和西南部,较高生态安全空间集中分布于高生态安全空间外围,且相对集中于中部,二者空间分布呈持续扩张趋势。中等生态安全的空间分布呈西北—东南走向条带状,较低态安全空间集中分布于研究区西北部及东南部,低生态安全空间则主要集中分布于北部,且在南部有较少分布,三者空间分布皆呈不断减少趋势。(4)研究区生态夹点7个,高警戒修复区188.17 km^(2),修复后最大累积电流由值4.75 A降至3.82 A。

An ecological security pattern can promote regional ecological development and be highly beneficial for preserving ecologically fragile areas.Urumqi of Xinjiang,China,is a typical oasis city in an arid area.In an era of rapid development of industrialization and urbanization,because of the topographical and geological limitations and uneven spatial distribution of water and soil resources,the trade-off between regional agricultural development,ecological protection,and urbanization development is a concern.Therefore,the development of an effective method for the analysis of the temporal and spatial evolution of ecological security patterns is critical.In this study,the principle of“ecological source identification-resistance surface construction-ecological corridor extraction”was used.Based on these factors and the evaluation of the importance of ecosystem services and ecological sensitivity,the land use data of Urumqi in 2000,2010,and 2020 were used to identify the ecological source.Next,the ecological corridors were extracted using the minimum cumulative resistance model.Furthermore,ecological pinch points were determined using the circuit theory.Finally,the resistance threshold method was used to develop the ecological security space and define the high alert restoration area.The results revealed the following:(1)In recent 20 years,the area of ecological source areas has increased considerably,and its area of 445.63 km^(2)was more than 3.19%of the study area.The newly increased ecological source areas were distributed in Urumqi County and Dabancheng District in the southwest and east of the study area.(2)In the three periods,27,30,and 40 ecological corridors with a total length of 870.42 km,1115.83 km,and 1277.12 km,respectively,were identified.(3)The spatial distribution of the five levels of ecological security in the study area was uneven.The northeast,southwest,and periphery regions of the study area had a concentration of high ecological security spaces,whereas the middle region had a moderate concentration.The two spatial distributions revealed a continuous expansion trend.The medium ecological security space showed zonal distribution from northwest to southeast in the study area,whereas low ecological security space was concentrated in the north and sparse in the south.The spatial distribution of the three space types exhibited a decreasing trend.(4)Seven ecological pinch points were observed in the study area.The areas of high alert repaired were 188.17 km^(2).The maximum accumulated current was reduced from 4.75 A to 3.82 A after restoration.The results can effectively coordinate the contradictory relationship between economic development and ecological protection in the study area.The results of the study can provide a scientific foundation and support the territory development plan for optimizing ecological civilization construction.