Han Haojie, Yan Xing, Li Xiaohan, Huang Zelin, Yan Xiaoyuan, Xia Yongqiu
State Key Laboratory of Soil and Sustainable Agriculture, Changshu National Agro-Ecosystem Observation and Research Station, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 211135, China; University of Chinese Academy of Sciences, Beijing, 100049, China; University of Chinese Academy of Sciences, Nanjing, 211135, China.
State Key Laboratory of Soil and Sustainable Agriculture, Changshu National Agro-Ecosystem Observation and Research Station, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 211135, China.
J Environ Manage. 2025 May;381:125306. doi: 10.1016/j.jenvman.2025.125306. Epub 2025 Apr 12.
Determining the optimal riparian buffer zone based on the relationship between landscape metrics and water quality is a widely used method for water quality management. However, failing to account for the differences between various segments of the same river can lead to inaccurate identification of riparian buffer zones, thereby affecting the effectiveness of water quality improvement. Here, based on water quality monitoring data from January 2023 to December 2023 in different segments (JuRong segment and XieXi segment) of a typical traditional-intensive agricultural watershed (Qinhuai River watershed), we identified the differences in the optimal riparian buffer zone on water quality between different segments within the same river through redundancy analysis (RDA) and variance partitioning analysis (VPA). Subsequently, utilizing the nonparametric change-point analysis (nCPA), we further identified the critical landscape thresholds causing abrupt changes in water quality within the optimal riparian buffer zone. Results showed that in the JuRong segment, the optimal width for riparian buffer zones was 100 m, with landscape metrics explaining 96.7% of the water quality variation. In the XieXi segment, the optimal riparian buffer zone width was 600 m, with landscape metrics explaining 82.6% of the water quality variation. Interspersion and Juxtaposition index of water (IJI_Water) and Interspersion and Juxtaposition index of Garden (IJI_Garden) were found to be the most influential landscape metrics on water quality in the JuRong and XieXi segments, respectively. Furthermore, the landscape thresholds of IJI_Garden and IJI_Water resulting in abrupt changes in water quality were 68.50 and 39.88 in the JuRong segment, and 76.07 and 56.39 in the XieXi segment, respectively. This study highlights the importance of considering the varying effects in optimal riparian buffer zones and developing distinctive water quality management strategies between different segments within the same river.
基于景观指标与水质之间的关系确定最佳河岸缓冲带是水质管理中广泛使用的方法。然而，未能考虑同一条河流不同河段之间的差异可能导致河岸缓冲带识别不准确，从而影响水质改善效果。在此，基于典型传统集约农业流域（秦淮河流域）不同河段（句容段和渫西段）2023年1月至2023年12月的水质监测数据，我们通过冗余分析（RDA）和变异分解分析（VPA）确定了同一条河流不同河段最佳河岸缓冲带对水质影响的差异。随后，利用非参数变点分析（nCPA），我们进一步确定了导致最佳河岸缓冲带内水质突变的关键景观阈值。结果表明，在句容段，河岸缓冲带的最佳宽度为100米，景观指标解释了96.7%的水质变化。在渫西段，最佳河岸缓冲带宽度为600米，景观指标解释了82.6%的水质变化。水的散布与并列指数（IJI_Water）和园地的散布与并列指数（IJI_Garden）分别被发现是句容段和渫西段对水质影响最大的景观指标。此外，导致句容段水质突变的IJI_Garden和IJI_Water的景观阈值分别为68.50和39.88，渫西段分别为76.07和56.39。本研究强调了考虑最佳河岸缓冲带不同影响以及制定同一条河流不同河段独特水质管理策略的重要性。
