Santos et al. (2026) Estimates of soil loss and sediment deposition in the Wadi Ouahrane Basin in northern Algeria based on the WaTEM/SEDEM model

Identification

• Journal: Journal of Sedimentary Environments
• Year: 2026
• Date: 2026-03-10
• Authors: Celso Augusto Guimarães Santos, Mohammed Achite, Gleycielle Rodrigues do Nascimento, Ana Paula Xavier Dantas, Kusum Pandey, Richarde Marques da Silva
• DOI: 10.1007/s43217-026-00287-4

Research Groups

• Department of Civil and Environmental Engineering, Federal University of Paraíba, João Pessoa, Paraíba, Brazil
• Faculty of Nature and Life Sciences, Water and Environment Laboratory, Hassiba Benbouali University of Chlef, Chlef, Algeria
• National Institute of Himalayan Environment, Kosi-Katarmal, Almora, Uttarakhand, India
• Department of Geosciences, Federal University of Paraíba, João Pessoa, Paraíba, Brazil

Short Summary

This study applied the WaTEM/SEDEM model to assess spatiotemporal soil erosion and sediment dynamics in the Wadi Ouahrane Basin, north-central Algeria, from 1973 to 2017, revealing significant internal sediment deposition and a total river export of 39,000 kg.

Objective

• To assess the spatiotemporal dynamics of soil erosion and sediment deposition in the Wadi Ouahrane Basin (north-central Algeria) from 1973 to 2017, with particular attention to the key driving factors influencing these processes.

Study Configuration

• Spatial Scale: Wadi Ouahrane Basin, north-central Algeria, encompassing approximately 270,000,000 m² (270 km²). The basin is located between latitudes 36°00′ and 36°24′ N and longitudes 01°00′ and 01°03′ E, with an altitudinal gradient ranging from 160 m to 1,000 m.
• Temporal Scale: 1973 to 2017.

Methodology and Data

• Models used:
  • Water and Tillage Erosion Model Sediment Delivery Model (WaTEM/SEDEM)
  • Revised Universal Soil Loss Equation (RUSLE) for calculating average annual soil loss (A = R × K × L × S × C × P)
  • Equations for transport capacity (Tc = Ktc × R × K × (LS − 4.12 × S^0.8))
  • Equation for tillage erosion (QD = klS = kl dh/dx)
• Data sources:
  • Rainfall erosivity factor (R): Daily precipitation data (1973–2017) from Agence Nationale des Ressources Hydriques (ANRH) and the National Meteorological Office of Algeria.
  • Soil erodibility factor (K): Gridded soil dataset from OpenLandMap (250 m spatial resolution).
  • Topographic factor (LS): MERIT Hydro dataset (3 arc-seconds, approximately 90 m spatial resolution).
  • Cover management factor (C): Mean Normalised Difference Vegetation Index (NDVI) values calculated from satellite-based Moderate Resolution Imaging Spectroradiometer (MODIS) products (2001–2020).
  • Support practice factor (P): Slope-dependent empirical approach (Panagos et al., 2015) derived from the MERIT Hydro Digital Elevation Model.
  • Tillage diffusion constant (ktil): Calibrated area-averaged value of 600 kg/m².
  • Input maps: Raster format, 20 m spatial resolution, prepared using TerrSet software.

Main Results

• Rainfall Erosivity (R): R values ranged from 75 to 116 MJ·mm·ha⁻¹·h⁻¹·year⁻¹, with an average of 95.5 MJ·mm·ha⁻¹·h⁻¹·year⁻¹. The highest values were in the northeastern basin, and the lowest in the western portion.
• Cover Management Factor (C): C-factor values ranged from 0 to 0.45, indicating varying levels of soil cover and erosion potential.
• Net Water Erosion: Values varied from -0.002 to 0.00435 kg·m⁻²·year⁻¹. The northeastern basin exhibited the highest rates, while southern and western areas showed lower erosion.
• Tillage Erosion: Values ranged from -0.027 to 0.0365 kg·m⁻²·year⁻¹. Moderate to high tillage erosion was observed in the central and southeastern regions.
• Total Soil Erosion: Most areas ranged from -0.027 to 0.005 kg·m⁻²·year⁻¹. Localized hotspots of severe soil loss (-0.027 to -0.0085 kg·m⁻²·year⁻¹) were concentrated in the northern and northeastern zones.
• Sediment Balance: Values ranged from -0.00028 to 0.00065 kg·m⁻²·year⁻¹. The northeastern region was identified as a net sediment source, while some central and southern zones exhibited depositional behavior.
• Sediment Budget (1973-2017):
  • Total sediment yield: 355,000 kg
  • Total sediment deposition within the basin: 72,000 kg
  • Total sediment export from source areas: 283,000 kg
  • Total river export (sediment exiting the basin): 39,000 kg
• The study suggests that converting cultivated zones into arable land can enhance landscape sustainability by reducing soil erosion, sediment transport, and reservoir siltation.

Contributions

• First application of the WaTEM/SEDEM model in the Wadi Ouahrane Basin, addressing a methodological gap in regional soil erosion assessment.
• Provides a comprehensive spatial and quantitative assessment of soil erosion and sediment dynamics, including both water and tillage erosion, in a semi-arid environment.
• Identifies critical erosion hotspots and depositional zones, offering valuable guidance for targeted soil and water conservation strategies.
• Offers practical implications for land and water management, including planning for reforestation, conservation tillage, reservoir maintenance, and land-use zoning.
• Reinforces the need for integrated basin management strategies that combine scientific modeling with on-the-ground conservation efforts.

Funding

• Brazilian Federal Agency for the Support and Evaluation of Graduate Education (CAPES) – Finance Code 001.
• Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) (ROR identifier: 00x0ma614) for the Article Processing Charge (APC).

Citation

@article{Santos2026Estimates,
  author = {Santos, Celso Augusto Guimarães and Achite, Mohammed and Nascimento, Gleycielle Rodrigues do and Dantas, Ana Paula Xavier and Pandey, Kusum and Silva, Richarde Marques da},
  title = {Estimates of soil loss and sediment deposition in the Wadi Ouahrane Basin in northern Algeria based on the WaTEM/SEDEM model},
  journal = {Journal of Sedimentary Environments},
  year = {2026},
  doi = {10.1007/s43217-026-00287-4},
  url = {https://doi.org/10.1007/s43217-026-00287-4}
}