Évaluation quantitative de l’érosion hydrique sur les terrains marneux du PréRif oriental (Maroc) : cas du sous-bassin de l’oued Tlata

Black marls form very extensive outcrops in the Alps and constitute some of the most eroded terrains, thus causing major problems of sedimentation in artificial storage systems (e.g. reservoirs) and river systems. In the experimental catchments near Draix (France), soil erosion rates have been measured in the past at the plot scale through a detailed monitoring of surface elevation changes and at the catchment scale through continuous monitoring of sediment yield in traps at basin outlets. More recently, erosion rates have been determined by means of dendrogeomorphic techniques in three monitored catchments of the Draix basin. A total of 48 exposed roots of Scots pine have been sampled and anatomical variations in annual growth rings resulting from denudation analysed. At the plot scale, average medium-term soil erosion rates derived from exposed roots vary between 1·8 and 13·8 mm yr −1 (average: 5·9 mm yr −1 ) and values are significantly correlated with slope angle. The dendrogeomorphic record of point-scale soil erosion rates matches very well with soil erosion rates measured in the Draix basins. Based on the point-scale measurements and dendrogeomorphic results obtained at the point scale, a linear regression model involving slope angle was derived and coupled to high-resolution slope maps obtained from a LiDAR-generated digital elevation model so as to generate high-resolution soil erosion maps. The resulting regression model is statistically significant and average soil erosion rates obtained from the areal erosion map (5·8, 5·2 and 6·2 mm yr −1 for the Roubine, Moulin and Laval catchments, respectively) prove to be well in concert with average annual erosion rates measured in traps at the outlet of these catchments since 1985 (6·3, 4·1 and 6·4 mm yr −1 ). This contribution demonstrates that dendrogeomorphic analyses of roots clearly have significant potential and that they are a powerful tool for the quantification and mapping of soil erosion rates in areas where measurements of past erosion is lacking.

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“…Clarke and Rendell, 2010), Morocco (e.g. Tribak et al, 2009), and Israel (e.g. Kuhn and Yair, 2004).…”

Section: Introductionmentioning

confidence: 99%

Mapping of erosion rates in marly badlands based on a coupling of anatomical changes in exposed roots with slope maps derived from LiDAR data

Lopez-Saez¹,

Corona²,

Stoffel

et al. 2011

Earth Surf. Process. Landforms

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“…Evaluación de los usos del suelo y la erosión hídrica en la subcuenca hidrográfica montañosa del Oued Ourtza ... software IDRISI SELVA 17 que utiliza el MDT (Modelo Digital de Terreno), a partir del cual obtiene el grado de la pendiente, su orientación y longitud acumulada y, finalmente, el factor SL. -El valor del factor C utilizado, se ha basado tanto en los resultados de estudios similares relativos a ciertas cuencas del Rif estudiadas con anterioridad (Kalman, 1967;Heusch, 1990;Tribak et al, 2009;El Garouani et al, 2009;Sadiki et al, 2004;Naimi et al, 2004), como en las imágenes de satélite y las observaciones de campo. Los valores asignados a los diversos modos de uso del suelo se sitúan entre 0,08 para los bosques abiertos que ocupan algunas cumbres en la zona alta de la subcuenca y 0,75 para los terrenos desnudos sin cultivar y ampliamente distribuidos sobre las pendientes más pronunciadas.…”

Section: Modelización De La Erosión Del Suelounclassified

Evaluación de los usos del suelo y la erosión hídrica en la subcuenca hidrográfica montañosa del Oued Ourtza (Pre-Rif Oriental, Marruecos)

Tribak

Baena-Escudero

Amador

et al. 2021

Ingeo

Self Cite

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Se estudia la distribución espacial de los usos del territorio y de pérdida de suelo en la subcuenca hidrográfica del Oued Ourtza (Pre-Rif Oriental, Marruecos) entre los años 2000 y 2014. Para ello, se ha recurrido a información extraída de imágenes de satélite, el empleo de la ecuación universal de pérdida de suelo en su versión adaptada a las condiciones mediterráneas (RUSLE) y el correspondiente tratamiento mediante herramientas SIG. Las cartografías resultantes denotan la sustitución de los cultivos tradicionales de cereal por otros arbóreos y un importante abandono de las tierras (36,8%). Las pérdidas de suelo son bastante altas (40 t·ha-1·año-1), muy por encima de su tolerancia, aunque están cercanas a las tasas de ablación registradas en otras áreas del entorno mediterráneo y el Rif marroquí. Estas pérdidas se distribuyen desigualmente, correspondiendo las tasas más elevadas con las tierras no cultivadas o abandonadas (>80 t·ha-1 ·año-1) cuya extensión sigue aumentando, sobre todo, en los tramos medio y bajo de la subcuenca donde dominan los materiales lábiles.

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Soil erodibility mapping using the RUSLE model to prioritize erosion control in the Wadi Sahouat basin, North-West of Algeria

Toubal

Achite

Ouillon

et al. 2018

Environ Monit Assess

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Soil losses must be quantified over watersheds in order to set up protection measures against erosion. The main objective of this paper is to quantify and to map soil losses in the Wadi Sahouat basin (2140 km) in the north-west of Algeria, using the Revised Universal Soil Loss Equation (RUSLE) model assisted by a Geographic Information System (GIS) and remote sensing. The Model Builder of the GIS allowed the automation of the different operations for establishing thematic layers of the model parameters: the erosivity factor (R), the erodibility factor (K), the topographic factor (LS), the crop management factor (C), and the conservation support practice factor (P). The average annual soil loss rate in the Wadi Sahouat basin ranges from 0 to 255 t ha year, maximum values being observed over steep slopes of more than 25% and between 600 and 1000 m elevations. 3.4% of the basin is classified as highly susceptible to erosion, 4.9% with a medium risk, and 91.6% at a low risk. Google Earth reveals a clear conformity with the degree of zones to erosion sensitivity. Based on the soil loss map, 32 sub-basins were classified into three categories by priority of intervention: high, moderate, and low. This priority is available to sustain a management plan against sediment filling of the Ouizert dam at the basin outlet. The method enhancing the RUSLE model and confrontation with Google Earth can be easily adapted to other watersheds.

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Évaluation quantitative de l’érosion hydrique sur les terrains marneux du PréRif oriental (Maroc) : cas du sous-bassin de l’oued Tlata

Cited by 8 publications

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Mapping of erosion rates in marly badlands based on a coupling of anatomical changes in exposed roots with slope maps derived from LiDAR data

Mapping of erosion rates in marly badlands based on a coupling of anatomical changes in exposed roots with slope maps derived from LiDAR data

Evaluación de los usos del suelo y la erosión hídrica en la subcuenca hidrográfica montañosa del Oued Ourtza (Pre-Rif Oriental, Marruecos)

Soil erodibility mapping using the RUSLE model to prioritize erosion control in the Wadi Sahouat basin, North-West of Algeria

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