Effects of local land-use policies and anthropogenic activities on water quality in the upstream Sesan River Basin, Vietnam
Effects of local land-use policies and anthropogenic activities on water quality in the upstream Sesan River Basin, Vietnam
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DOI：
10.1016/j.ejrh.2022.101225
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发表时间：
2022-12
期刊：
影响因子：
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通讯作者：
Vo Ngoc Quynh Tram;H. Somura;T. Moroizumi;M. Maeda
中科院分区：
文献类型：
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作者：
Vo Ngoc Quynh Tram;H. Somura;T. Moroizumi;M. Maeda
研究区域本研究的重点是越南中部高地的五桑河上游流域。研究重点：地方土地利用政策和人类活动可以显著影响下游地区的水文，并增加侵蚀和营养的程度。利用SWAT （Soil and water Assessment Tool）评估了2000-2018年期间陆地区域对目标区域水质的影响，并根据不同时期的地方政策决定和农业实践更新了土地利用条件。本研究表明，与土地利用政策实施前相比，地方土地利用政策的实施以及广泛的人为活动对下游水生环境产生了显著影响。Poko流域上游以牧地为主，而Dakbla流域南部和西南部以耕地和永久农田为主，年泥沙、总氮和总磷的负荷较高。在2005-2009年期间（开展造林、农业扩张和城市化）和2010-2014年期间（实施从混交林向橡胶林转变的作物转种政策），可耕地向河段的泥沙和养分负荷比例最高。了解流域特征，结合空间土地利用、地方土地利用政策和农业实践，将有助于更全面地实施区域土地利用和水资源管理战略。
Study regionThis study focuses on the upstream Sesan River Basin in the Central Highlands of Vietnam.Study focusLocal land-use policies and human activities can significantly affect hydrology and increase the magnitude of erosion and nutrients in downstream areas. The effects in terrestrial regions on water quality of the target area were evaluated during the 2000–2018 period using the SWAT (Soil and Water Assessment Tool) with updated land-use conditions following the local policy decisions and agricultural practices in different periods.New hydrological insights for the regionsThis study indicates that the implementation of the local land-use policies, along with extensive anthropogenic activities, has had significant effects on the downstream aquatic environment as compared with the period before the implementation of the land-use policies. Higher annual sediment, total nitrogen (TN), and total phosphorus (TP) loadings were found upstream from the Poko Watershed, where range land predominated, and in southern and southwestern Dakbla Watershed, where arable land and permanent cropland predominated. Arable land had the highest proportion of sediment and nutrient loadings into the reach, especially in the 2005–2009 period (conducting afforestation, agricultural expansion, and urbanization) and in the 2010–2014 period (applying crop conversion policy involving a shift from mixed forests to rubber forests). Understanding the watershed characteristics along with the combination of spatial land use, local land-use policies, and agricultural practices will support the implementation of regional land use and water resources management strategies more comprehensively.