Embedded Files
Hydrological dynamics of North and South Korea, considering the transboundary river context, infrastructure, and climate variability
The Korean Peninsula is shaped by sharply divergent political and economic systems, which have produced very different approaches to water-resources management. As a result, hydrologic regimes in North and South Korea are distinctive—not only in their physical behavior, but also in their societal drivers and impacts.
In North Korea, long-standing efforts to achieve food self-sufficiency under international constraints have contributed to widespread deforestation and agricultural expansion. This land-use conversion has reduced watershed water-storage capacity and increased hydrologic vulnerability. For instance, forest clearing and terracing on steep hillslopes (≥16°) has been reported across more than 2 million hectares. In contrast, South Korea is often cited as a global afforestation success story and has developed highly systematic and engineered water-resources governance.
At the same time, transboundary river systems are influenced by both physical processes and political tensions. In the Imjin River, for example, unannounced reservoir releases from North Korea have periodically produced damaging floods downstream in South Korea (Jang et al., 2020). In September 2009, an estimated ~40 × 10⁶ m³ release over ~02:00–13:00 raised river stage by ~2.3 m, causing six fatalities and approximately US$0.5 million in property damage. Sediment dynamics in these systems remain highly variable and continue to evolve, producing distinctive geomorphic and hydrologic patterns.
River bar dynamics in the transboundary river system (Imjin River)
River bar dynamics in the transboundary river system (Imjin River)
Cho M. S. (2026). Distinct geomorphic responses of river bars in the dammed transboundary river. Geomorphology. Manuscript submitted for publication.
River bars are key depositional landforms whose evolution reflects the interplay of discharge, sediment supply, and vegetation, and is strongly modulated by dam regulation and extreme floods. In transboundary rivers, fragmented spatial planning and limited operational coordination can superimpose abrupt, unannounced releases on regulated, sediment-deficient flow regimes, complicating attribution of geomorphic change. Here we quantify contrasting river-bar responses along the Imjin River, North and South Korea, following the August 2020 flood pulse associated with an upstream release and downstream attenuation by Gunnam Dam. This paper delineated 10 m time-series boundaries for 82 river bar from 112 Sentinel-2 acquisitions (2016–2024) using a U-Net semantic segmentation model and compared pre- and post-event conditions in bar area, spatial erosion–deposition patterns, and annual bar migration upstream versus downstream Upstream bars increased in area (median +27%) and showed a characteristic pattern of head and riverward erosion with tail and landward accretion, accompanied by downstream centroid migration (mean 293 m yr⁻¹). Downstream bars decreased in area (median −14%) and exhibited dominant riverward erosion without consistent head/tail or landward signals, with primarily bankward migration (mean 209 m yr⁻¹). These results indicate that episodic flood pulses can periodically reset bar morphology upstream, whereas clear-water releases and sediment deficits more persistently constrain bar growth downstream. Our framework demonstrates how dense, deep-learning-enabled remote sensing can resolve spatially divergent geomorphic responses in dammed transboundary rivers under compounded anthropogenic forcing.
Lake dynamics over four decades
Lake dynamics over four decades
Cho, M. S., & Park, J. (2024). Spatiotemporal lake area changes influenced by climate change over 40 years in the Korean Peninsula. Scientific Reports, 14(1), 1144.
Water resources in lakes of the Korean Peninsula play a significant role in society and ecosystems in both South and North Korea. This study characterized spatiotemporal changes in the lake area during the dry season (March-May) in the Korean Peninsula over the last 40 years. The satellite images (Landsat 5-9) were used to derive annual areas of 975 lakes during the dry season from 1984 to 2023. Our analysis indicated that the MNDWI is the optimal remote sensing-based index for delineating lake areas in the Korean Peninsula, with an overall accuracy of 92.3%. Based on the selected index, the total lake areas of the dry seasons have increased from 1070.7 km² in 1984 to 1659.3 km² in 2023, mainly due to newly constructed dam reservoirs. While the detailed changes in lake area vary, we found divergent results based on their sizes. The large lakes (> 10 km²) showed their area increased by 0.0473 km² (0.1%) every year and have more influences from climate change. On the contrary, the small lakes (≤ 10 km²) have area decreases by 0.0006-0.006 km2 (0.15-0.5%) every year and have less influence from climate change. This study shows that the spatiotemporal lake area changes are determined by either climate change or human activity.
Page updated
Google Sites
Report abuse