Hydrological-Hydraulic Modeling with climate change impact and influence of the Curve Number (CN) in the Ichu river basin, Huancavelica-Peru (#1017)

Authors

Ayala Bizarro, Ivan Arturo

Castillo Navarro, Leonardo

Zuñiga Mendoza, Jessica

Abstract

The intensification of extreme hydrometeorological events driven by climate change presents a significant challenge for water resource management and flood control in vulnerable regions. This study evaluates the combined impacts of climate change and soil-abstraction characteristics on runoff processes in the experimental Ichu River basin, located in the central Andes of Peru, using distributed hydrological-hydraulic models on the HEC-RAS platform and Curve Number (CN) parameters derived from high-resolution data (Sentinel-2 and SoilGrid). The results show that under saturated soil conditions (CN III), climate change increases peak discharge (Qp) by 20.1% and total runoff volume by 12.9%, whereas in less saturated soils (CN II), the relative increases are 28.7% and 22.6%, respectively, although with lower absolute values. Additionally, the temporal assessment (2017–2023) demonstrated hydrological stability when climatic conditions remain consistent, suggesting that climatic factors prevail over land-use changes under these conditions. However, critical areas were identified where soil degradation due to urbanization and deforestation increases runoff risk, as well as regions with improvements associated with reforestation and sustainable management, highlighting the effectiveness of these measures. This work underscores the importance of integrating distributed models, high-resolution geospatial data, and tools such as GPCN10 for automated CN calculation, providing a robust foundation for designing adaptive strategies to mitigate climate change impacts on watershed hydrology and promote sustainable water resource management.