Large weir construction causes the loss of seasonal habitat in riverine wetlands: a case study of the Four Large River Projects in South Korea
Large weir construction causes the loss of seasonal habitat in riverine wetlands: a case study of the Four Large River Projects in South Korea
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DOI：
10.1016/j.ecoleng.2020.105839
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发表时间：
2020-06
影响因子：
3.8
通讯作者：
R. Im;Ji Yoon Kim;J. Nishihiro;G. Joo
中科院分区：
文献类型：
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作者：
R. Im;Ji Yoon Kim;J. Nishihiro;G. Joo
2009年至2012年，韩国在四条河流上开展了全国性的建设项目；十六座大型堰是为了控制洪水风险和保障水资源。环境影响评价通过对比调查后的记录和施工前的记录来评价条件变化。然而，从长远的角度来看，对该堰的生态评价仍然有限。在这项研究中，我们利用33年的卫星图像数据库，比较了韩国两个建筑工地（洛东江和锦江）和一个参考地点（Seomjin江）的河流生境的长期动态。基于年洪涝频次，将30 m格网河流生境分为永久水、季节性水和非洪涝生境3种时间类型，并对其时间趋势进行了比较。建堰后，永久水域面积增加（洛东区+36.0%，锦区+10.9%）；季节性生境和非淹水生境的R值分别为- 36.5%和- 37.4%，锦区R值分别为- 22.9%和- 28.2%。生境向不同生境类型转换的年通量仅在堰地有所减少。在不同的生境过渡类型中，在筑坝期间生境向永久水转变的程度最高。我们对河流栖息地的长期分析可以用来了解建堰和疏浚河道后的时间变化和恢复。
From 2009 to 2012, South Korea carried out national-wide construction projects in four rivers; sixteen large-weirs were constructed to control flood risk and to secure water resources. Environmental impact assessment of the weir construction evaluated conditional changes by comparing post-survey records with pre-construction periods. However, the ecological assessment for the weir construction in a long-term perspective has been still limited. In this study, we compared the long-term dynamics of riverine habitat in two construction sites (Nakdong River and Geum River), and one reference site (Seomjin River) in South Korea using 33-years database of satellite imagery. We classified 30 m-grid riverine habitats into three temporal types (i.e., permanent water, seasonal water, and non-flooded habitat) based on annual flooding frequency and its temporal trend was compared. After weirs construction, the area of permanent water was increased (Nakdong R.: +36.0%, Geum R.: +10.9%); seasonal habitat and non-flooded habitat were decreased (Nakdong R: −36.5% and −37.4%; Geum R: −22.9% and −28.2%, respectively). And annual flux of habitat transitions into different habitat types has been decreased only in weir construction sites. Among different habitat transition categories, habitat change into permanent water was the highest during the weir construction periods. Our long-term analysis of riverine habitat can be used to understand temporal changes and recovery after weir construction and channel dredging.