Daraghma et al. (2025) Impacts of climate change on the water budget elements in the Faria catchment, Palestine

Identification

• Journal: Journal of Water and Climate Change
• Year: 2025
• Date: 2025-09-25
• Authors: Qais Daraghma, Abdelhaleem Khader
• DOI: 10.2166/wcc.2025.139

Research Groups

• Faculty of Graduate Studies, An-Najah National University, Nablus, Palestine
• Department of Civil Engineering, An-Najah National University, Nablus, Palestine

Short Summary

This study assesses the impacts of climate change on water budget components in the semi-arid Faria catchment, Palestine, using climate projections and hydrological modeling. It projects significant reductions in groundwater recharge and surface runoff, alongside increased evapotranspiration, leading to decreased water yield and threatening regional water security.

Objective

• To investigate the impact of climate change on meteorological variables in the Faria catchment for 2060 and 2100 under SSP2-4.5 and SSP5-8.5 scenarios using the SimClim AR6 model.
• To model the hydrological cycle in the Faria catchment using SWAT to analyze the impact of climate change on water budget elements (runoff, evaporation, groundwater recharge) based on baseline daily data (1990–2021).
• To quantify future surface runoff, evapotranspiration, and groundwater recharge from rainfall in the Faria catchment for 2060 and 2100 under the selected climate scenarios.

Study Configuration

• Spatial Scale: Faria catchment (approximately 320 km²), West Bank, Palestine, delineated into 33 sub-basins and 597 Hydrological Response Units (HRUs).
• Temporal Scale: Baseline period (1990–2021) for model calibration and validation; future projections for two periods: 2060 and 2100.

Methodology and Data

• Models used:
  • SimClim AR6: For generating future climate projections from an ensemble of 23 General Circulation Models (GCMs) under SSP2-4.5 and SSP5-8.5 scenarios, including spatial bias correction.
  • Soil and Water Assessment Tool (SWAT2012) via ArcSWAT: For hydrological modeling of the catchment, simulating water budget components (surface runoff, evapotranspiration, water yield, groundwater recharge).
  • SUFI-2 algorithm (within SWAT-CUP): For parameter optimization, uncertainty analysis, and sensitivity analysis during model calibration and validation.
• Data sources:
  • Climate Projections: SimClim AR6 ensemble of 23 GCMs (2060, 2100).
  • Baseline Meteorological Data (1990–2021):
    • Rainfall: Palestinian Meteorological Department (point gauges).
    • Temperature, relative humidity, wind speed, solar radiation: NASA-POWER (0.5° × 0.5° grid).
    • Bias correction data: WorldClim (1 km) and CRUTS4.05 archives.
  • Topography: Digital Elevation Model (DEM) from Geomolg (Palestinian MoLG & GIZ) (25 m × 25 m resolution).
  • Land Use: Geomolg (30 m × 30 m resolution).
  • Soil Properties: FAO Global Soil Dataset (approximately 1 km × 1 km resolution).
  • Observed Streamflow: Parshall flumes at Badan sub-catchment (2004–2007, daily data) for model calibration and validation.

Main Results

• Climate Projections:
  • Annual rainfall is projected to decline by 5.77–6.82% by 2060 under SSP2-4.5, intensifying to 17.64–20.88% by 2100 under SSP5-8.5.
  • Minimum temperatures are expected to rise by 2.26–2.32 °C (SSP2-4.5, 2060) and 6.90–7.11 °C (SSP5-8.5, 2100).
  • Maximum temperatures are projected to increase by 2.36–2.47 °C (SSP2-4.5, 2060) and 7.22–7.57 °C (SSP5-8.5, 2100).
  • Relative humidity is predicted to decrease by up to 4.28% by 2100 under SSP5-8.5.
  • Solar radiation is projected to increase by 3.55–3.98% by 2100 under SSP5-8.5.
• Hydrological Model Performance:
  • Calibration (2004–2006): R² = 0.67, NSE = 0.64 (satisfactory).
  • Validation (2006–2007): R² = 0.73, NSE = 0.52 (satisfactory).
  • Sensitivity analysis identified CN2 (SCS runoff curve number) as the most influential parameter.
• Water Budget Component Changes:
  • Surface Runoff (SRO): Projected to decrease significantly. For sub-basin 18 (highest SRO), reductions are 11.25% (SSP2-4.5, 2060) to 33.03% (SSP5-8.5, 2100).
  • Evapotranspiration (ET): Projected to increase overall. For sub-basin 6 (lowest baseline ET), increases are 3.53% (SSP2-4.5, 2060) to 9.79% (SSP5-8.5, 2100). The highest ET increase was 2.3% over baseline in sub-basin 3 under SSP5-8.5 by 2100.
  • Water Yield (WY): Projected to decrease significantly. For sub-basin 18 (highest WY), reductions are 8.07% (SSP2-4.5, 2060) to 29.7% (SSP5-8.5, 2100).
  • Groundwater Recharge: Projected to decrease due to lower rainfall and higher ET. For sub-basin 8 (highest recharge), reductions are 9.28% (SSP2-4.5, 2060) to 29.07% (SSP5-8.5, 2100).
• Monthly Analysis: ET peaks intensify in summer, SRO and groundwater recharge diminish in winter, and WY declines are most pronounced in spring, exacerbating water stress during critical agricultural periods.

Contributions

• First study to comprehensively assess climate change impacts on water budget elements in the Faria catchment, Palestine, using integrated climate-hydrology modeling.
• Utilizes an ensemble of 23 GCMs from SimClim AR6 under SSP2-4.5 and SSP5-8.5 scenarios for robust local climate forecasting.
• Provides spatially explicit and quantitative projections of future changes in surface runoff, evapotranspiration, water yield, and groundwater recharge.
• Highlights the urgent need for adaptive water management strategies in semi-arid regions, particularly for agricultural water security.
• Employs a hydroclimatic disturbance framework linking climatic drivers to hydrological system redistribution.

Funding

Not explicitly stated in the provided text.

Citation

@article{Daraghma2025Impacts,
  author = {Daraghma, Qais and Khader, Abdelhaleem},
  title = {Impacts of climate change on the water budget elements in the Faria catchment, Palestine},
  journal = {Journal of Water and Climate Change},
  year = {2025},
  doi = {10.2166/wcc.2025.139},
  url = {https://doi.org/10.2166/wcc.2025.139}
}