| 不同尺度土地利用方式对地表水环境质量的影响及驱动机制 |
| 摘要点击 1781 全文点击 648 投稿时间：2021-08-22 修订日期：2021-11-06 |
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| 中文关键词 地表水环境质量 土地利用 水体富营养化 面向对象 若尔盖湿地 |
| 英文关键词 surface water environment quality land use eutrophication of water body object-oriented Ruoergai wetland |
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| 中文摘要 |
| 土地利用作为人类活动的重要载体对地表水环境状况有重要影响.以若尔盖湿地为例，基于面向对象的土地利用类型遥感解译，结合水质检测数据，从小流域和缓冲区尺度，分析不同尺度土地利用方式对地表水环境的影响及驱动机制.结果发现：①若尔盖湿地水质为Ⅴ类水，且整体呈现轻度富营养化，主要污染物为总氮（TN）和总磷（TP），污染来自生活污水和放牧；②土地利用方式与地表水环境质量联系紧密，水体面积占比与化学需氧量（COD）呈现负相关关系、沼泽面积占比与TN呈现正相关关系和TP呈现负相关关系；③不同尺度土地利用方式与地表水环境存在显著关联性，1000 m缓冲范围内的土地利用方式解释度最高，200 m的土地利用方式对COD的解释度最大，500 m的土地利用方式对TP和TN的解释度最大，800 m的土地利用方式对叶绿素（Chl-a）的解释度最大.本研究结果表明：若尔盖湿地对污染物和富营养化有一定的净化作用，但不同的土地利用方式对不同污染物作用存在差异，水体对Fe2+、COD和Chl-a有净化作用，沼泽对TP有净化作用但对TN却呈现累积效应.应控制小尺度（≤1000 m）的土地利用格局，对水体和沼泽的面积进行重点管控，重视提升湿地水域的自净能力，进一步保护和修复若尔盖湿地地表水环境. |
| 英文摘要 |
| As an important carrier of human activities, the spatial type of land use has an important impact on the surface water environment. Taking the Ruoergai wetland as an example, based on object-oriented remote sensing interpretation of land use types combined with water quality examination data, this study analyzed the impact and driving mechanism of land use types at different scales on the surface water environment at the small watershed and buffer scale. ① It was found that the water quality of the Ruoergai wetland could been classified as water grade V, and it was slightly eutrophic as a whole. The main pollutants were total nitrogen(TN) and phosphorus(TP), and the pollution originated from domestic sewage and grazing. ② The environmental quality of surface water was closely related to land use types. There was a negative correlation between chemical oxygen demand(COD) and the proportion of water area, a positive correlation between TN and the proportion of swamp area, and a negative correlation between total TP. ③ There was a significant correlation between spatial land use types at different scales and surface water environment. The land use type within a buffer of 1000 m had the highest interpretation degree for all factors, the land use type within a buffer of 200 m had the greatest interpretation degree for COD, the land use type within a buffer of 500 m zone had the greatest interpretation degree for TP and TN, and the land use type within a buffer of 800 m had the greatest explanation for Chl-a. The results of this study showed that the Ruoergai wetland wetland had a certain purification effect on pollutants and eutrophication. However, different land use types had different effects on different pollutants. The water body had a purification effect on Fe2+, COD, and Chl-a, and the swamp had a purification effect on TP but a cumulative effect on TN. Thus, the small-buffer zone(≤ 1000 m) land use type should be controlled, the water body and swamp areas should be controlled, the self-purification capacity of wetland waters should be improved, and the surface water environment of the Ruoergai wetland should be further protected and repaired. |
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