Landslide susceptibility mapping using AHP method and GIS in the peninsula of Tangier (Rif-northern morocco)

Abstract

The peninsula of Tangier (Northern Morocco) is submitted to a significant number of landslides each year due to its lithological, structural and morphological complexity; which cause a lot of damage to the road network and other related infrastructure. The main objective of this study is to create a landslide indexed susceptibility map of Tangier peninsula, by using AHP (Analytical Hierarchical Processes) model to calculate each factor’s weight. The work is made via GIS by using an ArcGIS AHP extension. In the current research, First of all, the four main types of landslides were identified and mapped from existing documents, works and new data which came from either remote sensing or fieldwork. Lithology, land use, slope, hypsometry, exposure, fault density and drainage network density were used as main parameters controlling the occurrence of the selected landslides. Then, afterward, each parameter is classified into a number of significant classes based on their relative influence on gravitational movement genesis. The validity of the susceptibility zoning map which is obtained through linear summation of indexed maps was tested and cross-checked by inventoried and studied landslides. The obtained landslide susceptibility map constitutes a powerful decision-making tool in land-use planning, i.e. New highways, secondary highways, railways, etc. within the national development program in the Northern provinces. It is a necessary step for the landslides hazard assessment in the Tangier peninsula in northern Morocco.

Assessment of the Erosion and Outflow Intensity in the Rif Region under Different Land Use and Land Cover Scenarios

“…Most of these studies give the results in t/ha/year, while the EPM-IntErO models are not widely used in Morocco [20,64]. For example, the average rate in the Nakhla catchment is 38.7 t/ha/year [65], while the RUSLE and SWAT models in the Arbaa Ayacha catchment showed 25.77 tha −1 y −1 and 28.09 tha −1 y −1 , respectively [29]. Erosion in the Raouz catchment area is estimated at 26.6 tha −1 y −1 using remote sensing [66] and 16.53 tha −1 y −1 using the RUSLE model [67].…”

“…Figure 3. Erosion rates were obtained for the current situation in (a) m 3 /km 2 /year, (b) t/ha/year, (c) for reforestation in Scenario 1, (d) cropping and plowing in Scenario 2 Compared to other sections of the Moroccan Rif, the average erosion rate in the R'mel basin is low.For example, the average rate in the Nakhla catchment is 38.7 t/ha/year[65], while the RUSLE and SWAT models in the Arbaa Ayacha catchment showed 25.77 tha −1 y −1 and 28.09 tha −1 y −1 , respectively[29]. Erosion in the Raouz catchment area is estimated at 26.6 tha −1 y −1 using remote sensing[66] and 16.53 tha −1 y −1 using the RUSLE model[67].…”

Landslide Hazard Assessment in the Heterogeneous Geomorphological and Environmental Context of the Rif Region, Morocco – A Machine Learning Approach

“…For example, Hierarchical Fuzzy Inference Systems (HFIS) that were applied in the Rif Mountains' center region (Ozer et al, 2020) and fuzzy Analytical Hierarchy Process (FAHP) were combined for landslide susceptibility modeling in southeast Morocco (Sadiki et al, 2023); Weight Of Evidence (WOE) was applied in Tetouan-Ras Mazar (Elmoulat & Ait Brahim, 2018), an area of the Rif chain (Es-smairi et al, 2021) and Taounate-Ain Aicha . Logistic regression (LR) was used in Taounate-Oudka and the Sahla catchment area (El-Fengour et al, 2021), while the Analytical Hierarchical Processes (AHP) method was applied in Tangiers (Brahim et al, 2018), the Larache Province (Hamdouni et al, 2022) and parts of the Rif mountains (Es-smairi et al, 2021). However, these methods rely on assumptions about the data, such as normality and linearity, which can limit their accuracy in analyzing complex interrelationships between different causative factors.…”

Evaluation of the Effect of Hydroseeded Vegetation for Slope Reinforcement

“…In qualitative methodologies divided into geomorphic and heuristic methods, such as AHP [51][52][53] and weighted linear combination [8,54,55], weights and ranks are assigned by the experts regardless of any existing landslide inventory maps and terrain variations [28]. The deterministic approach includes static and dynamic methods that evaluate landslide hazards using slope stability models, which results in the calculation of safety factors.…”

“…AHP, first developed by Saaty [62], is categorized under this qualitative approach and applied by several researchers for landslide susceptibility assessment [51,52,66,67]. AHP uses a hierarchical process of landslide parameters to compare possible pairs and assign weights and a consistency ratio [8].…”