Elomari et al. (2026) Hydrological Assessment of Climate Change Impacts on the Upper Tassaoute Watershed, Morocco

Identification

• Journal: BIO Web of Conferences
• Year: 2026
• Date: 2026-01-01
• Authors: Sana Elomari, Oussama Nait-taleb, El Mahdi El Khalki, Fatima-Ezzahra El-Kamouni, Insaf Ouchkir, Jaouad El Atiq, Abdenbi Elaloui
• DOI: 10.1051/bioconf/202621101015

Research Groups

• Data4Earth Laboratory, Faculty of Sciences and Technology, Sultan Moulay Slime University, Beni Mellal, Morocco
• International Water Research Institute (IWRI), Mohammed VI Polytechnic University, Ben Guerir, Morocco
• Geomatics, Georesources and Environment Laboratory, Faculty of Sciences and Technology, Sultan Moulay Slime University, Beni Mellal, Morocco

Short Summary

This study assessed the hydrological impacts of recent climate variability on the Upper Tassaoute Watershed, Morocco, using the HBV model, revealing a significant reduction in streamflow and altered seasonal water availability linked to observed rainfall and temperature changes.

Objective

• To assess the impacts of recent climatic changes (variations in rainfall and temperature patterns) on water resources, specifically streamflow and seasonal water availability, in the Upper Tassaoute Watershed, Morocco, using the HBV conceptual hydrological model.

Study Configuration

• Spatial Scale: Upper Tassaoute Watershed, a tributary of the Oum Er-Rbia basin in central Morocco.
• Temporal Scale: Monthly data from 1990 to 2021 (32 years).

Methodology and Data

• Models used: HBV (Hydrologiska Byråns Vattenbalansavdelning) conceptual hydrological model.
• Data sources: Monthly meteorological data (precipitation, temperature) and hydrological data (streamflow/discharge) collected from meteorological and hydrological stations. Potential evapotranspiration (PET) was estimated using the Thornthwaite method.

Main Results

• The HBV model achieved satisfactory calibration performance at the monthly scale for the period 1990–2021, with an overall Nash–Sutcliffe Efficiency (NSE) of 0.811, a Coefficient of Determination (R²) of 0.812, and a Root Mean Square Error (RMSE) of 3.48 mm/day.
• The model successfully reproduced seasonal streamflow dynamics, including the timing of rising and recession periods, peak discharge events, and low-flow periods.
• Model performance varied annually, showing excellent agreement (NSE > 0.90, R² > 0.94) in some years (e.g., 1991, 1993, 2009, 2014, 2015) but weaker performance (NSE < 0.30, sometimes negative) during extreme hydrological conditions (e.g., 1998, 2000, 2001, 2004, 2018).
• Sensitivity analysis identified Field Capacity (FC), Soil Moisture Nonlinearity Exponent (BETA), and Fast Runoff Coefficient (k0) as the most sensitive parameters, highlighting their dominant role in runoff generation and soil moisture dynamics in the catchment.
• The study indicates a noticeable reduction in streamflow and changes in seasonal water availability, which are closely linked to observed variations in rainfall and temperature patterns over recent decades.

Contributions

• Provides a comprehensive hydrological assessment of recent climate change impacts on water resources in the Upper Tassaoute Watershed, a crucial semi-arid region in Morocco.
• Demonstrates the effectiveness and suitability of the HBV conceptual model for simulating streamflow and water balance dynamics in data-limited, semi-arid environments at a monthly scale.
• Offers a scientific basis for improving water resource management and climate adaptation planning in the vulnerable region.
• Identifies the most sensitive hydrological parameters (FC, BETA, k0) for this specific semi-arid catchment, guiding future modeling efforts and data collection.

Funding

No specific funding projects, programs, or reference codes were mentioned in the provided paper text.

Citation

@article{Elomari2026Hydrological,
  author = {Elomari, Sana and Nait-taleb, Oussama and Khalki, El Mahdi El and El-Kamouni, Fatima-Ezzahra and Ouchkir, Insaf and Atiq, Jaouad El and Elaloui, Abdenbi},
  title = {Hydrological Assessment of Climate Change Impacts on the Upper Tassaoute Watershed, Morocco},
  journal = {BIO Web of Conferences},
  year = {2026},
  doi = {10.1051/bioconf/202621101015},
  url = {https://doi.org/10.1051/bioconf/202621101015}
}