学术论文

      洱海流域土地利用变化及其对景观生态风险的影响

      Effect of land use change on landscape ecological security in Erhai Basin

      摘要:
      为探析高原湖泊所集成的小尺度自然流域景观空间变化及其对景观生态风险的影响,以云南洱海流域3期(1995年、2005年和2015年)Landsat遥感影像解译数据为基础,利用GIS空间分析技术和Fragstats软件计算景观格局指数,并在此基础上构建了景观生态风险指数,对洱海流域生态风险时空变化及其演化机制进行了分析.结果表明:1995-2015年,流域土地景观类型面积变化表现为林、草地和水体面积减少,耕地和湿地面积先减少后增加,建设用地面积显著增加的变化特点;景观指数定量分析表明,流域景观空间异质性下降,景观类型分布趋于从集中向分散转变,林地对流域景观的控制作用减弱;20年来,流域生态趋于恶化,生态风险指数均值由1995年的0.4998上升到2015年的0.5896,高生态风险面积所占的比重由1995年的34.0%上升到2015年的47.8%,生态风险空间分布由主要沿流域外沿分布转变为以环洱海地带为重心的多极分布;流域生态风险时空变化与土地利用类型的演变及人类活动关系密切,大规模旅游开发和城乡发展机制上的差异是导致该区域高生态风险等级区域增多和转移的重要原因.
      Abstract:
      To study the landscape spatial change of small-scale natural watersheds integrated by plateau lakes and its impacts on landscape ecological risk,Landsat remote sensing image interpretation data in Erhai Lake Basin in 1995,2005 and 2015 were used,and GIS spatial analysis technique and Fragstats 3.4 were used to calculate the landscape pattern index.Accordingly,the landscape ecological risk model was constructed,and the temporal and spatial characteristics of ecological risk and its evolution mechanism in Erhai Lake Basin were analyzed.The results showed that:(1) The area of landscape types changed obviously from 1995 to 2015 in Erhai Basin.Woodland,grassland and water landscape decreased gradually,the cultivated land and wetland decreased first and then increased,while the construction land increased significantly.(2) The quantitative analysis of landscape index in Erhai Basin showed that the landscape spatial heterogeneity decreased,and the landscape type distribution changed from centralized to scattered,and as a result,the control effect of woodland was weakened.(3) During the past 20 years,the ecological security of the watershed tended to deteriorate,the average ecological risk index changed from 0.4998 in 1995 to 0.5896 in 2015,the proportion of high ecological risk area changed from 34.0% in 1995 to 47.8% in 2015,and the distribution of high ecological risk region changed from the arc pattern along the periphery of the basin to the multi-core pattern centered on the Erhai Lake.The spatial and temporal changes of the ecological risk of the basin were closely related to the evolution of land use types and human activities.Large-scale tourism development and the differences in urban-rural development mechanism were important factors leading to the increase and transfer of high ecological risk area in this region.
      Author: WANG Tao ZHANG Chao YU Xiao-tong CAO Xiao-wang
      作者单位: 西南林业大学林学院,昆明,650224
      刊 名: 生态学杂志 ISTICPKU
      年,卷(期): 2017, 36(7)
      在线出版日期: 2017年8月8日
      基金项目: 国家自然科学基金项目