| 摘要: |
| 为探究流域内水质对土地利用的响应关系,本研究基于不同空间尺度(1000 m河段缓冲区、500 m河岸带缓冲区及子流域缓冲区)的土地利用指数以及旱季(2019年11月)、雨季-洪水期(2020年7月)和雨季-干旱期(2022年8月)的水质数据,探究流域内土地利用对水质的多时空尺度影响,从而得到保护流域水质和规划流域内土地利用格局的最佳时空尺度。研究表明:(1)流域水质受极端天气影响,表现为雨季-洪水期的水质较好,雨季-干旱期次之,旱季较差；(2)耕地是主要的土地利用类型,景观格局指数斑块密度(PD)和景观优势度(LPI)在1000 m河段缓冲区更大,景观分离指数(DIVISION)和景观形状指数(LSI)在子流域尺度更大,边缘密度(ED)和香农多样性指数(SHDI)在500 m河岸带缓冲区更大；(3)土地利用对水质指标的影响存在时空尺度效应,子流域和旱季为影响河流水质最显著的尺度；(4)不同土地利用指数对流域水质影响存在差异,耕地、林地、PD、LPI和ED是水质指标重要的解释变量。其中林地与多数水质指标具有负相关关系,是河流水体污染物的“汇”景观,而“源”景观主要为建设用地和耕地,与较多水质指标存在正相关关系。本研究结果为合理规划土地利用格局以及保护河流[1]水质提供科学依据,对人类生存环境可持续发展及生态保护具有一定意义。 |
| 关键词: 河流水质 土地利用指数 多时空尺度 冗余分析 三峡库区 |
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| 基金项目:国家自然科学(42107091),重庆市自然科学基金面上项目 (cstc2020jcyj-msxmX0549),重庆市教委科学技术研究计划项目 (KJQN202200517),重庆师范大学(20XLB022) |
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| Effects of land use on riverine water quality at multiple spatial and temporal scales in the Three Gorges Reservoir area under extreme weather conditions |
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Zhang Qiong, Liu Rui, Zhang Jing, Zheng Dayan, Zhang Liuliu, Zheng Caigui
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Chongqing Normal University
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| Abstract: |
| To explore the response relationship between water quality and land use in the basin, this study based on the land use index of different spatial scales ( 1000 m river buffer zone, 500 m riparian buffer zone and catchment buffer zone ) and the water quality data of dry season ( November 2019 ), rainy season-flood season ( July 2020 ) and rainy season-arid period ( August 2022 ), to explore the multi-spatial and temporal scale effects of land use on water quality in the basin, so as to obtain the best spatial and temporal scale for protecting water quality and planning land use pattern in the basin. The research shows that : ( 1 ) The water quality of the basin is affected by extreme weather, which is better in the rainy season-flood season, followed by the rainy season-dry season, and the dry season is poor. ( 2 ) Cultivated land is the main land use type. The landscape pattern index patch density ( PD ) and landscape dominance index ( LPI ) are larger in the buffer zone of 1000 m. The landscape separation index ( DIVISION ) and landscape shape index ( LSI ) are larger in the sub-watershed scale. The edge density ( ED ) and Shannon diversity index ( SHDI ) are larger in the buffer zone of 500 m.( 3 ) The impact of land use on water quality indicators has a spatial and temporal scale effect, and catchment and dry season are the most significant scales affecting river water quality. Cultivated land, forest land, PD, LPI and ED are important explanatory variables for water quality indicators. Among them, forest land is negatively correlated with most water quality indicators, which is the " sink " landscape of river water pollutants, while the " source " landscape is mainly construction land and cultivated land, which is positively correlated with many water quality indicators. The results of this study provide a scientific basis for rational planning of land use pattern and protection of river water quality, and have certain significance for the sustainable development of human living environment and ecological protection. |
| Key words: Riverine water quality Land use indices Multi-temporal and spatial scale Redundancy analysis Three Gorges Reservoir area |
