Abstract 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.

中文翻译：

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大堰建设导致河流湿地季节性栖息地丧失：以韩国四大河流项目为例

摘要 2009年至2012年，韩国在全国范围内开展了四条河流建设项目；建造了 16 座大堰以控制洪水风险并确保水资源安全。堰施工的环境影响评估通过比较勘察后记录与施工前时期来评估条件变化。然而，从长远来看，对堰坝建设的生态评价仍然有限。在这项研究中，我们使用 33 年的卫星图像数据库比较了韩国两个建筑工地（洛东河和锦江）和一个参考站点（Seomjin 河）的河流栖息地的长期动态。我们将 30 米网格的河流栖息地分为三种时间类型（即永久水、季节性水、和非洪水栖息地）基于年洪水频率及其时间趋势进行了比较。建堰后，永久水域面积增加（洛东河：+36.0%，锦河：+10.9%）；季节性栖息地和非洪水栖息地减少（洛东 R：-36.5% 和 -37.4%；Geum R：分别为 -22.9% 和 -28.2%）。仅在堰坝施工现场，栖息地向不同栖息地类型过渡的年流量有所减少。在不同的生境过渡类别中，堰施工期生境转变为永久水体的比例最高。我们对河流栖息地的长期分析可用于了解堰建造和渠道疏浚后的时间变化和恢复。Geum R.：+10.9%)；季节性栖息地和非洪水栖息地减少（洛东 R：-36.5% 和 -37.4%；Geum R：分别为 -22.9% 和 -28.2%）。仅在堰坝施工现场，栖息地向不同栖息地类型过渡的年流量有所减少。在不同的生境过渡类别中，堰施工期生境转变为永久水体的比例最高。我们对河流栖息地的长期分析可用于了解堰建造和渠道疏浚后的时间变化和恢复。Geum R.：+10.9%)；季节性栖息地和非洪水栖息地减少（洛东 R：-36.5% 和 -37.4%；Geum R：分别为 -22.9% 和 -28.2%）。仅在堰坝施工现场，栖息地向不同栖息地类型过渡的年流量有所减少。在不同的生境过渡类别中，堰施工期生境转变为永久水体的比例最高。我们对河流栖息地的长期分析可用于了解堰建造和渠道疏浚后的时间变化和恢复。生境转变为永久水体在堰施工期间最高。我们对河流栖息地的长期分析可用于了解堰建造和渠道疏浚后的时间变化和恢复。生境转变为永久水体在堰施工期间最高。我们对河流栖息地的长期分析可用于了解堰建造和渠道疏浚后的时间变化和恢复。