Li Kun, Xie Yu-Jing, Sun Wei, Wang Xiang-Rong, Li Zhao-Hua, Wang Ling
Faculty of Resource and Environmental Science, Hubei University, Wuhan 430062, China.
Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China.
Ying Yong Sheng Tai Xue Bao. 2020 Jun;31(6):2057-2066. doi: 10.13287/j.1001-9332.202006.036.
Understanding the response of water quality in lake to landscape pattern at different spatial scales in agricultural watershed is of great significance to water quality management. In this study, we classified seven riparian buffer zones of lakeside zone by ArcGIS and RS in the Honghu Lake, according to the five functional areas. The landscape metrics were analyzed at multiple buffer widths using Fragstats software. Mathematical statistical methods and models such as redundancy analysis were used to explore spatial relationship between water quality and landscape patterns. Results showed that: 1) The effect of landscape patterns on water quality was scale-dependent at multiple buffer widths. The highest total explanatory power between landscape characteristics and water quality was found at the 200 m buffer width, accounting for 86.1% of the total, which was the most effective spatial scale affecting water quality. 2) The landscape configuration (e.g., largest patch index, patch density) was more associated with water quality than landscape composition (e.g., the percent of landscape and evenness index). 3) The impacts of different landscape types on water quality varied. Agriculture land, affected by topography and cultivation mode, was the main influencing factor on the degradation of water quality at smaller buffer widths from 100 m to 500 m. Forests with higher density and area had more purification effect on water pollutants at the wider buffer widths from 1000 m to 5000 m. The impacts of grassland on water quality was similar with that of forests, but densely distributed urban land contributed to water quality degradation at the same buffer widths. This study could provide scientific reference for water quality management and landscape planning of lake basin in agricultural areas.
了解农业流域不同空间尺度下湖泊水质对景观格局的响应，对水质管理具有重要意义。本研究利用ArcGIS和RS技术，根据五个功能区对洪湖湖滨带的七个河岸缓冲带进行了分类。使用Fragstats软件分析了多个缓冲宽度下的景观指标。采用冗余分析等数理统计方法和模型，探讨水质与景观格局之间的空间关系。结果表明：1）景观格局对水质的影响在多个缓冲宽度上具有尺度依赖性。在200米缓冲宽度下，景观特征与水质之间的总解释力最高，占总量的86.1%，是影响水质最有效的空间尺度。2）景观配置（如最大斑块指数、斑块密度）比景观组成（如景观百分比、均匀度指数）与水质的相关性更强。3）不同景观类型对水质的影响各不相同。受地形和耕作方式影响，农业用地是100米至500米较小缓冲宽度下水体质量退化的主要影响因素。在1000米至5000米较宽缓冲宽度下，密度和面积较大的森林对水污染物的净化作用更强。草地对水质的影响与森林相似，但在相同缓冲宽度下，密集分布的城市用地会导致水质退化。本研究可为农业区湖泊流域的水质管理和景观规划提供科学参考。
