Li Biao, Huang Xiaolei, Zhong Qiang, Wu Xiuxiu
National Engineering Laboratory for Applied Technology of Forestry & Ecology in Southern China, Central South University of Forestry and Technology, Changsha, 410004, China.
College of Life and Environmental Sciences, Central South University of Forestry and Technology, Changsha, 410004, China.
Sci Rep. 2025 Apr 19;15(1):13528. doi: 10.1038/s41598-025-98575-y.
Landscape features have a profound impact on river water quality. However, its impact in subtropical hilly region is unclear. Here, water quality data from 15 catchments were obtained based on a typical subtropical hilly area, the upper Ganjiang River basin. The landscape features in the catchment and buffer zone were calculated, and its effects on river water quality were investigated using redundancy analysis (RDA) and multiple linear regression (MLR) model. Catchment landscape features were found to better explain overall water quality changes compared to buffer zone, and landscape features were found to explain water quality changes more in winter than in summer. Moreover, within the buffer zone, the percentage of grassland had the greatest impact on winter water quality (72.8%), while at the catchment scale, the aggregation index (AI) of grassland contributed the most to changes in winter water quality (31.6%). Nonparametric change-point analysis (nCPA) was used to identify thresholds of landscape features that lead to abrupt changes in water quality. It was found that river water quality can be improved when the percentage of grassland > 0.193%, the largest patch index (LPI) of forest > 7.48% at the buffer zone or the percentage of impervious surfaces < 2.92%, the AI of forest > 98.6% at the catchment scale. This study demonstrated the pivotal role in enhancing river water quality by implementing informed and effective landscape planning for conservation implementation.
景观特征对河流水质有深远影响。然而，其在亚热带丘陵地区的影响尚不清楚。在此，基于典型的亚热带丘陵地区——赣江上游流域，获取了15个集水区的水质数据。计算了集水区和缓冲区内的景观特征，并使用冗余分析（RDA）和多元线性回归（MLR）模型研究了其对河流水质的影响。结果发现，与缓冲区相比，集水区景观特征能更好地解释整体水质变化，且景观特征对冬季水质变化的解释力大于夏季。此外，在缓冲区内，草地比例对冬季水质影响最大（72.8%），而在集水区尺度上，草地的聚集度指数（AI）对冬季水质变化贡献最大（31.6%）。采用非参数变点分析（nCPA）来确定导致水质突变的景观特征阈值。结果发现，当草地比例>0.193%、缓冲区森林的最大斑块指数（LPI）>7.48%或不透水表面比例<2.92%、集水区尺度森林的AI>98.6%时，河流水质可得到改善。本研究表明，通过实施明智且有效的景观规划以进行保护，在提升河流水质方面具有关键作用。
