TITLE:
Modelling Soil Erosion and Sedimentation in the Oued Haricha Sub-Basin (Tahaddart Watershed, Western Rif, Morocco): Risk Assessment
AUTHORS:
Mounia Tahiri, Hassan Tabyaoui, Abdelfatah Tahiri, Hassan El Hadi, Fatima El Hammichi, Mohammed Achab
KEYWORDS:
Soil Erosion, Deposition, Oued Haricha, NW-Rif, Morocco
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.4 No.1,
January
18,
2016
ABSTRACT: This
study evaluates the annual loss of soil in the sub-basin of Oued Haricha
(Tahaddart basin, Western Rif, NW Morocco). The integration of revised (RUSLE)
and modified (MUSLE) soil loss empirical equations of Wischmeier and Smith in
combination with GIS permits the modelling of soil erosion at the scale of
parcels. The characteristics of precipitation and runoff, the soil properties,
the culture system and the current working practices of soil in the sub-basin
of the Oued Haricha are collected from local data. The digital terrain model is
used to generate topographic factors. The combination of different RUSLE
factors shows that the annual soil is 62.72 t/ha/year and corresponds to an
average level of risk. The total losses calculated by MUSLE method are valued at
221,468 t/year. The rates of loss due to linear erosion are 82,652 t/year.
These soil losses represent 20.33% of the total losses, and confirm that the
losses on the slopes outweigh the losses due to the river system. Sedimentation
module shows that the areas of high erosion (greater than 200 t/ha/year) are
concentrated in the reliefs with average and high slope and occupy 38% of the
total area. The deposition areas occupy the centre of sub-basin and constitute
9.12% of the total area. These deposits were concentrated on the edges of major
rivers and the outlet of the sub-basin and contributed to siltation of the
April 9, 1947 dam.