基于不透水地表扩展的南昌市景观生态风险评价

Assessment on Landscape Ecological Risk in Nanchang City Based on Impervious Surface Expansion

[目的]景观生态风险是识别区域生态风险和衡量区域生态安全的有效指标。基于不透水地表构建,可直观判定人类活动对风险形成及恶化的环境响应。分析区域景观生态风险评价及风险加剧区的影响因素,对遏制风险加剧区的滋生与蔓延具有科学意义及实践价值。[方法]以南昌市为例,获取不透水地表信息构建景观生态风险指数,分析其时空演变特征,运用地理探测器对研究区景观生态风险的影响因素进行测度。[结果](1) 2010-2020年南昌市不透水地表面积剧烈增长,由648.63 km^(2)增至1 075.12 km^(2),农用地及生态用地资源不断下降,不透水地表主要由耕地、林地、水域等景观转换而来,人类活动干扰程度加大;(2) 2010-2020年南昌市景观生态风险指数空间分布以“中间低-两边高”呈现,平均值整体下降。2010年、2015年、2020年南昌市景观生态高风险区面积分别为519.73 km^(2),324.82 km^(2),365.04 km^(2),景观生态高风险区面积先降后升,区域以景观生态中高风险区及中风险区为主;(3) 2010年、2015年、2020年南昌市景观生态风险的影响因素由社会经济因子与距离因子为主导,影响因子的交互作用均大于单因子的解释程度,距离因子对自然气候因子与社会经济因子具有正向提升作用;(4)南昌市景观生态风险加剧区以林地、水域、耕地等景观类型为主,加剧区是自然环境、社会经济及可达性等多重因素导致,但人为活动影响更为突出。[结论]南昌市景观生态状况向好。自然环境、社会经济、距离等因子对景观生态风险指数及风险加剧区的影响呈现差异性和交互性。研究结果对维护区域生态安全和可持续发展具有重要意义。

[Objective]Landscape ecological risk is an effective indicator to identify regional ecological risks and measure regional ecological security.Based on the construction of impervious surface,the environmental response of human activities to the formation and exacerbation of risks can be intuitively determined.Regional landscape ecological risk assessment and the influencing factors of the aggravated risk areas are analyzed,which has scientific significance and practical value for curbing the emerging and spreading of risk exacerbation zones.[Methods]Nanchang City was taken as an example,the information of impervious surface was obtained to construct a landscape ecological risk index.The spatiotemporal evolution characteristics of landscape ecological risk were analyzed.The influencing factors of landscape ecological risk in the study area was measured by using geographic detectors.[Results](1)From 2010 to 2020,the area of impervious surface in Nanchang City increased dramatically,from 648.63 km^(2)to 1075.12 km^(2),and the resources of agricultural land and ecological land continued to decline.The impervious surface was mainly converted from landscapes such as cultivated land,forest land,and water areas,and the degree of interference from human activities increased.(2)From 2010 to 2020,the spatial distribution of Nanchang′s landscape ecological risk index was presented as low in the middle and high on both sides.The average value of landscape pattern index decreased as a whole.In 2010,2015,and 2020,the areas of high-risk areas of landscape ecology in Nanchang City were 519.73 km^(2),324.82 km^(2),and 365.04 km^(2),respectively.The area of landscape ecological high-risk areas first decreased and then increased.The areas were dominated by landscape ecological medium-high-risk areas and medium-risk areas.(3)The influencing factors of landscape ecological risk in Nanchang City in 2010,2015 and 2020 were dominated by socio-economic factors and distance factors.The interaction effects of the influencing factors were all larger than the explanation degree of a single factor.The distance factor had a positive effect on natural climate factors and socioeconomic factors.(4)The landscape ecological risk exacerbation zone in Nanchang City was dominated by landscape types such as forest land,water area and cultivated land.Exacerbation zones were caused by multiple factors such as natural environment,socio-economics,and accessibility,but the impact of human activities was more prominent.[Conclusion]The landscape ecological status of Nanchang City has been improving.The impacts of natural environment,social economy,distance and other factors on the landscape ecological risk index and risk exacerbation areas are different and interactive.These research results are of great significance for maintaining regional ecological security and sustainable development.