Statistical analysis of a systematic review on soil water erosion assessment in Morocco

A large effort has been devoted over the past century to assessing soil erosion using a variety of methods under a wide range of climatic conditions, soil types, land uses, topography, and others. Thus, we attempt to provide an analysis of national data of several soil erosion modeling and fingerprinting. The methodology adopted for this research is a review of scientific articles, conference papers and thesis on soil erosion, focusing more on categorization of the different soil erosion models and methods applied. Based on the statistical analysis provided by this review, the results are as follows: (i) Even though the threat of soil erosion is grave, the number of studies conducted to characterize and evaluate soil erosion in Morocco is limited. (ii) Studies on water erosion modeling are concentrated in the north of the country (Rif 32.89%, High Atlas 32.89%, Occidental Meseta 18.43% and Middle Atlas 10.53%). (iii) Water erosion models have been steadily developed and interfaced with GIS based approaches in recent decades. (iv) Although Morocco is geomorphologically and geologically varied (Rif, Middle and High Atlas, Mesetian and Saharan domain), several authors use soil erosion assessment models that ignore the unique characteristics of each study area and fail to adapt them to local conditions. (v) USLE (R) models have been widely used and modified over the past two decades and remain the most commonly used modeling tool today. (vi) The largest proportion of the erosion rate is concentrated in the Atlas and Rif mountains. (vii) Demonstration of a strong relationship between soil erosion rates with environmental factors and modeling conditions, and the lack of correlation with study area size and erosion rate. While the overall results show a relatively high variance, which cannot be explained by this combination of factors, it is partly related to the experimental conditions. This review is intended to support future soil erosion assessment and to facilitate the identification of priorities for soil erosion research in Morocco by supplying a state of the art for future targeted and comprehensive analyses to deal with the issue of soil erosion in Morocco.Keywords: Soil water erosion models, Fingerprinting methods, Literature review, Morocco.