异龙湖流域生态安全格局构建与评价

Construction and Evaluation of Ecological Security Pattern in Yilong Lake Basin

高原湖泊是区域经济发展的重要载体,城镇化进程的推进和旅游业的发展对高原湖泊生态环境造成一定影响,高原湖泊流域的开发与其生态保护间的矛盾凸显,亟需开展高原湖泊流域生态安全研究。以异龙湖流域为研究区域,基于土地利用数据和DEM高程数据,运用综合指数法、熵值法和GIS空间分析技术,通过生态安全评价模型(ESI)对异龙湖流域生态安全进行评价,同时结合最小累积阻力模型(MCR),以源地-廊道-节点的方式构建异龙湖流域生态安全格局。结果表明,异龙湖流域中度安全区域占流域总面积的33.03%,较低安全区域占32.45%,不安全区域占20.36%,高度安全区域占14.16%,平均生态安全指数为2.34,总体处于中度安全状态,流域生态系统健康状况一般;高度安全区域集中分布在异龙湖国家湿地公园;坝心镇的生态安全状况最好,其次为异龙镇,宝秀镇最差。异龙湖流域生态源地总面积为128.45km^(2),占流域总面积的36.03%,呈现以异龙湖为中心、流域四周集中连片的分布特征,其中异龙湖国家湿地公园在该流域生态安全保护中占主导地位。识别出18个生态节点,并提取出20条生态廊道;根据计算结果将异龙湖流域划分为生态缓冲区(205.19 km^(2))、生态过渡区(65.31 km^(2))、生态边缘区(46.89 km^(2))、农业耕作区(26.79 km^(2))和人类活动区(12.30 km^(2))5个生态功能区,针对不同生态功能区的特点提出相应的管理和保护对策。

Plateau lakes are important carriers for regional economic development.With acceleration of urban⁃ization and development of tourism,ecological environments of plateau lakes were affected.Contradictions be⁃tween development of plateau lake basins and ecological protection were prominent.It was urgent to study eco⁃logical security of plateau lake basins.Taking Yilong Lake basin as study area,based on land use data and DEM elevation data,ecological security of Yilong Lake basin was evaluated by ecological security evaluation model(ESI)using comprehensive index method,entropy method and GIS spatial analysis technology.Combined with minimum cumulative resistance model(MCR),ecological security pattern of Yilong Lake basin was con⁃structed in the way of sources-corridors-nodes.Results showed that in Yilong Lake basin,medium security ar⁃ea accounted for 33.03%of total area of Yilong Lake basin;low security area accounted for 32.45%;insecurity area accounted for 20.36%;high security area accounted for 14.16%.Average ecological security index was 2.34,which indicated that whole ecological security was in medium level.Health status of basin ecosystem was in general.High security area concentrated in Yilong Lake National Wetland Park.Baxin town had the best eco⁃logical security,followed by Yilong town and Baoxiu town.Total area of ecological source in Yilong Lake basin was 128.45 km^(2),accounting for 36.03%of total area of Yilong Lake basin,which showed distribution character⁃istics of Yilong Lake as center and concentrated around basin.Yilong Lake National Wetland Park was domi⁃nant position in ecological security protection of the basin.A total of 18 ecological nodes and 20 ecological cor⁃ridors were identified.According to calculation results,Yilong Lake basin was divided into five ecological func⁃tion zones including ecological buffer zone(205.19 km^(2)),ecological transition zone(65.31 km^(2)),ecological fringe zone(46.89 km^(2)),agricultural cultivation zone(26.79 km^(2))and human activity zone(12.30 km^(2)).Corre⁃sponding management and protection measures were proposed based on characteristics of different ecological function zones.