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2026 Vol.59, Issue 2 Preview Page

Original research article

Evaluation of climate change impacts on soil loss in Saemangeum reclaimed coastal farmlands of Korea using the APEX model
Ye-Jun Lee1
,
Won-Ho Nam2*
,
Seong-Gyu Park3
,
Jin-Hyeob Kwak4
,
Kwang-Seung Lee5
1Graduate Student, School of Social Safety and Systems Engineering, Hankyong National University, Anseong 17579, Republic of Korea
2Professor, School of Social Safety and Systems Engineering, Institute of Agricultural Environmental Science, National Agricultural Water Research Center, Hankyong National University, Anseong 17579, Republic of Korea
3Assistant Professor, Department of Civil, Environmental, and Construction Engineering, Texas Tech University, Texas 79409, United States
4Associate Professor, Department of Rural Construction Engineering, Jeonbuk National University, Jeonju 54896, Republic of Korea
5Researcher, Reclaimed Land Agriculture Research Center, National Institute of Crop and Food Science, Rural Development Administration, Wanju 55365, Korea
*Corresponding Author
31 May 2026. pp. 157-171
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Abstract

This study evaluated the impacts of climate change on soil loss in the reclaimed coastal farmlands of South Korea using the Agricultural Policy/Environmental eXtender (APEX) model coupled with CMIP6-based multi-model ensemble (MME) climate projections. Two Shared Socioeconomic Pathways, SSP1-2.6 (low-emission) and SSP5-8.5 (high-emission), were analyzed for the near-future (2041 - 2070) and far-future (2071 - 2100) periods. Slope conditions were represented by three field treatments (0°, 3°, and 5°) established in large-scale reclaimed plots (40 × 45 m). To capture within-plot hydrologic variability and support slope-specific model calibration, soil water content was monitored at upper, middle, and lower sections for the 3° and 5° plots. The model demonstrated reliable performance, yielding coefficient of determination (R2) values exceeding 0.5 across all slope conditions. Simulation results indicated that average soil loss increased with slope gradient and was substantially exacerbated under the high-emission scenario. Under SSP1-2.6, the mean annual soil loss for the 5° slope increased by 49.7%, from 1.49 t ha-1 yr-1 (2041 - 2070) to 2.23 t ha-1 yr-1 (2071 - 2100). Under SSP5-8.5, the same slope exhibited a 72.0% surge, rising from 1.51 to 2.59 t ha-1 yr-1. Notably, even in flat areas (0°), soil loss increased by 22 - 44% depending on the scenario. The majority of this erosion was concentrated during the summer months (July - August), driven by intensified monsoon rainfall. These results underscore the increasing vulnerability of reclaimed coastal farmlands to long-term climate change. Ultimately, this study provides quantitative evidence to support targeted policies for sustaining soil productivity, improving field drainage, and ensuring the long-term sustainability of coastal agricultural lands.

The figure shows that simulated soil loss was concentrated during July–August and increased under SSP5-8.5, particularly on 5° slopes, highlighting slope-specific erosion control in reclaimed coastal farmlands.
Keywords
APEX model
CMIP6
Optimal slope
Reclaimed coastal farmland
Slope effect
Soil erosion
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Information
  • Publisher :Korean Society of Soil Science and Fertilizer
  • Publisher(Ko) :한국토양비료학회
  • Journal Title :Korean Journal of Soil Science and Fertilizer
  • Journal Title(Ko) :한국토양비료학회 학회지
  • Volume : 59
  • No :2
  • Pages :157-171
  • Received Date : 2025-11-12
  • Revised Date : 2026-03-05
  • Accepted Date : 2026-03-05
  • DOI :https://doi.org/10.7745/KJSSF.2026.59.2.157
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