景观空间异质性对地表水质服务的影响研究——以河南省伊河流域为例

Effects of landscape spatial heterogeneity on surface water quality service: A case study in Yihe River basin, Henan province

人类干扰使景观空间异质性发生了剧烈变化,进而对生态系统服务产生了严重影响。目前,针对景观空间异质性与生态系统服务的关联关系研究还较为薄弱。以河南省伊河流域为研究区域,以地表水质服务为研究对象,分析了地表水质服务的空间变化;通过以水质采样点为中心建立缓冲区,分析了不同尺度下的景观空间异质性特征,并与地表水质指标进行相关性研究,以探讨景观空间异质性与地表水质服务间的影响规律及响应机制。结果表明:(1)研究区地表水质状况整体上为西南、东北部较差,中部较好;(2)从景观组成来看,林地面积占比或斑块个数的增加有利于地表水质的提高;(3)类型水平上,林地的景观构型与化学需氧量的质量浓度在200 m半径缓冲区内显著相关(P<0.05),城镇用地的景观构型对地表水质的影响则在2000 m半径缓冲区内更为明显;(4)景观水平上,总磷的质量浓度受到景观构型变化的强烈影响(P<0.05),景观构型异质性越低,总磷的质量浓度就越高;(5)适当增加景观空间异质性可有效降低地表水质污染物的质量浓度,提高地表水质服务。研究结论可为伊河流域的空间开发及水环境保护政策的制定提供科学依据。

Human disturbance frequently and strongly works on landscape,which causes sharp change of landscape spatial heterogeneity,and then seriously influences ecosystem services.Currently,research on the correlation between landscape spatial heterogeneity and ecosystem services is still weak.Issues such as how landscape spatial heterogeneity affects ecosystem services,and what contributions it makes to sustain ecosystem services have to be solved urgently.This article chooses the Yihe River basin as a study area,and surface water quality service as the object.Concentrations of chemical oxygen demand,ammonia nitrogen and total phosphorus are selected and calculated to represent surface water quality,and the spatial distribution of surface water quality was analyzed.Buffer zones with 5 different lengths of radius were built around each of the 20 sampling sites to analyze the characteristics of landscape spatial heterogeneity at different scales.Correlation analysis was carried out to discuss the influencing rules and responding mechanisms between landscape spatial heterogeneity and surface water quality service.Results show that:(1)Surface water quality in the Yihe River basin is generally good,but in the southwest and northeast parts around urban areas,surface water quality is relatively poor.(2)Different landscape composition types affect surface water quality differently.From the aspect of landscape composition,it can be seen that if the area proportion or patch number of forest is increasing,surface water quality would improve simultaneously.(3)At the class level,there is a significant correlation between landscape configuration of forest and the concentration of chemical oxygen demand(P<0.05)within 200 m radius buffer zones,while the landscape configuration of urban areas would influence surface water more significantly within 2000 m radius buffer zones.(4)At the landscape level,the concentration of total phosphorus is strongly influenced by landscape configuration change(P<0.05),when landscape configurational heterogeneity is lower,the concentration of total phosphorus would be higher.(5)Increasing landscape spatial heterogeneity appropriately can effectively reduce the concentration of surface water pollutant and ensure the sustainability of surface water quality service.This study provides a scientific foundation for the spatial development and policy making for aquatic environmental protection in the Yihe River basin.