| 长江流域（重庆段）土地利用构成和景观格局对河流水质的多时空尺度影响 |
| 摘要点击 246 全文点击 5 投稿时间：2025-03-14 修订日期：2025-06-06 |
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| 中文关键词 水质 土地利用 多时空尺度 冗余分析 长江流域 |
| 英文关键词 water quality land use multiple space-time scales redundancy analysis Yangtze River Basin |
| DOI 10.13227/j.hjkx.202503160 |
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| 中文摘要 |
| 由于自然环境的异质性，不同区域土地利用与水质之间的影响模式也存在差异，探究土地利用对水质的影响对水环境的修复与保护具有重要意义. 基于长江流域（重庆段）水质监测数据和土地利用数据，提取监测站点子流域、河岸带500 m缓冲区和河段1000 m缓冲区这3个空间尺度上的土地利用构成和景观格局，并结合重庆市最新国土空间规划将研究区域分为4个区域（中心城区、主城新区、渝东北三峡库区城镇群和渝东南武陵山区城镇群），采用冗余分析等方法定量探讨了土地利用对河流水质的多时空尺度影响. 结果表明：①研究区河流整体水质旱季优于雨季，中心城区水质较好，主城新区水质最差，总氮是研究区主要水质污染物. ②土地利用对河流水质解释能力在旱季强于雨季，差异大小随空间尺度而变化：河段1 000 m缓冲区>河岸带500 m缓冲区>子流域. ③中心城区土地利用对河流水质影响最显著，土地利用与水质的关联程度最高在中心城区为河段1 000 m缓冲区，其他区域均为河岸带500 m缓冲区. ④耕地为河流水质的“源”景观，林地和草地在作为截流吸收污染物的“汇”的同时，在中心城区也是污染物的“源”，草地在渝东南武陵山区城镇群也是氮营养盐的主要来源. 建设用地对水质的影响在中心城区表现出两面性；边缘密度（ED）与水体污染物浓度正相关，聚合度（AI）与污染物浓度负相关，最大斑块指数（LPI）和香农多样性指数（SHDI）与污染物浓度的相关性存在区域差异. 可见不同季节和区域土地利用对河流水质的影响存在差异，应因地制宜优化景观结构，尤其是针对河流附近的人类活动，制定措施减缓污染物的排放，从而改善河流水质. |
| 英文摘要 |
| Due to the heterogeneity of the natural environment， there are also differences in the impact modes between land use and water quality in different regions. Exploring the impact of land use on water quality is of great significance for the restoration and protection of water environments. Based on water quality monitoring data and land use data in the Yangtze River Basin （Chongqing Section）， this study extracted the land use composition and landscape pattern at three spatial scales： sub-basin， the 500 m riparian buffer zone， and the 1 000 m river reach buffer zone. Combined with the latest territorial spatial planning of Chongqing， the study area was divided into four regions （the central urban area Chongqing municipality， new area for the central urban， urban agglomeration in the Three Gorges Reservoir area in northeast Chongqing， and urban agglomeration in the Wuling mountainous area in southeast Chongqing）， and the effects of land use characteristics on riverine water quality were quantitatively discussed by using redundancy analysis methods. The results showed that：① The overall water quality of the rivers in the study area was better in the dry season than in the rainy season. The water quality in the central urban area Chongqing municipality was the best， while that in the new area for the central urban area was the worst. Total nitrogen was the main water pollutant in the study area. ② The explanatory power of land use on river water quality was stronger in the dry season than in the rainy season， and the magnitude of the difference varied with the spatial scale： the 1 000 m river reach buffer zone > the 500 m riparian buffer zone > sub-basin. ③ The impact of land use on river water quality was most significant in the central urban area Chongqing municipality. The correlation between land use and water quality was the highest in the 1 000 m river reach buffer zone in the central urban area Chongqing municipality， while in other regions， it was in the 500 m riparian buffer zone. ④ Farmland was the “source” landscape for river water quality. Forest and grassland， while functioning as “sinks” for intercepting and absorbing pollutants， were also “sources” of pollutants in the central urban area Chongqing municipality. Grassland was also a major source of nitrogen nutrients in the urban agglomeration in the Wuling mountainous area in southeast Chongqing. The impact of construction land on water quality showed duality in the central urban area Chongqing municipality. Edge density（ED）was positively correlated with the concentration of water pollutants， aggregation index（AI）was negatively correlated with the concentration of pollutants， and the correlation between the largest patch index（LPI）and the Shannon's diversity index （SHDI）and pollutant concentration varied by region. The impact of land use on river water quality varied by season and region. Therefore， it is necessary to optimize the landscape structure based on local conditions， especially for human activities near rivers， and formulate measures to reduce pollutant emissions to improve river water quality. |
