Climate Inclusive Flood Inundation Modeling Using HEC-RAS: A Case Study of Panjkora River, Khyber Pakhtunkhwa, Pakistan
A Case Study of Panjkora River, Khyber Pakhtunkhwa Pakistan
Keywords:
ARC-GIS, ARC-SWAT, Shared Socioeconomic Pathway, Soil and Water Assessment Tool, Hydrologic Engineering , River Analysis SystemAbstract
Floods are among the most devastating climate-induced hazards, with severe socio-economic consequences, particularly in underdeveloped countries. Pakistan is highly vulnerable to climate change and has experienced several catastrophic flood events in recent decades. This study assesses future flood risks in the Panjkora River Basin, one of the major catchments in Khyber Pakhtunkhwa province, using hydrological and hydraulic modelling under different climate change scenarios. The Soil and Water Assessment Tool (SWAT) was employed to simulate hydrological processes using a 29-year weather dataset (1981–2010). Model calibration (1981–2002) and validation (2003–2010) demonstrated strong performance, with coefficient of determination (R²) values of 0.731 and 0.721 and Nash–Sutcliffe efficiency (NSE) values of 0.72 and 0.71, respectively. Future projections were analyzed under Shared Socioeconomic Pathways (SSP 2–4.5, moderate emissions, and SSP 5–8.5, high emissions) for three periods: near future (2026–2050), mid-century (2051–2075), and late century (2076–2099). Flood inundation mapping was conducted using the Hydrologic Engineering Centre’s River Analysis System (HEC-RAS). The results reveal a significant increase in flood inundation, particularly under SSP 5–8.5. Discharge is projected to increase by approximately 25% under SSP 2–4.5 and 27% under SSP 5–8.5 compared to the historical baseline. These findings underscore the increasing flood risks in the Panjkora River Basin under future climate change scenarios and highlight the need for adaptive water resource management and disaster risk reduction strategies in the region.
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