不同排水体制下城市河流水质对滨岸带用地变化的响应

Response of Urban River Water Quality to Spatial Land Use Change in a Riparian Zone Under Different Drainage Systems

[目的]探讨城市不同排水体制地区河流水质对滨岸带用地变化的响应,为以水环境提升和生态修复为目标导向的城市河流滨岸带规划和开发提供科学参考。[方法]以上海市苏州河为例,基于2018年水质与土地利用数据,运用生态景观格局结合冗余分析方法,定量探究河流水质在不同排水体制、不同滨岸带宽度上对用地变化的响应关系。[结果]①由自排区至强排区,苏州河滨岸用地结构、水质体现出明显时空差异,汛期水质(4—10月)劣于非汛期,自排区水质整体优于强排区;②自排区滨岸带水域、农业用地景观斑块密度在100—600 m的宽度上显著影响水质变化;③强排区滨岸带生态用地比例和斑块优势度是影响水质变化的关键因素,生态用地景观指数分别在100—1200 m的滨岸带宽度上对水质产生显著影响;④滨岸带用地在强排区1200 m宽度上对水质变化解释能力最大(56.9),且解释能力总体高于自排区。[结论]自排区与强排区河流滨岸带对水质空间变化影响的关键变量存在显著差异,强排区滨岸带景观要素对水质变化影响的程度较自排水区更强,范围更大。

[Objective]The objective of this study was to determine how the response relationship between urban riparian land use and water quality changes due to different drainage systems and riparian buffers in order to provide a practical reference for the planning and development of urban riparian zones resulting in improved water environment and ecological restoration.[Methods]We used redundancy analysis and the ecological landscape pattern method with water quality and land use data from Suzhou Creek in Shanghai in 2018 to quantitatively determine the response of river water quality to land use change for different drainage systems and different widths of riparian buffer zones.[Results]①Land use structure and water quality of the Suzhou Creek riparian area showed obvious spatial and temporal differences between the self-drainage area and the sewer-drainage area.Water quality during the flood season(April-October)was worse than during the non-flood season,and water quality in the self-drainage area was generally better than in the sewer-drainage area.②Landscape patch density of the water area and agricultural land in the riparian zone of the self-drainage area significantly affected the variation of water quality in the 100—600 m buffer width.③Proportion and patch dominance of ecological land significantly affected the variation of water quality in the riparian zone of the sewer-drainage area,and impacted water quality in a range of 100—1200 meters of the riparian buffer width.④Land use accounted for the greatest amount water quality change(56.9%)in the buffer width of the 1200 m riparian zone in the sewer-drainage area.The explanatory ability of the sewer-drainage area(44.1%—56.9%)was generally higher than that of the self-drainage area(31.1%—52.8%).[Conclusion]There were significant spatial differences in the key variables that influenced the relationship between riparian land use and water quality in the self-drainage area and the sewer-drainage area.In addition,landscape pattern showed a more intensive influence and a larger effect on the variation of water quality in the sewer-drainage area of the riparian zone.