Mapping the sensitivity of land degradation in the Ouergha catchment (Morocco) using the MEDALUS approach

Abstract

Soil degradation is a global phenomenon affecting the productivity of agricultural land. Due to the low vegetation cover and the aggressive climate, Morocco presents a significant case of soil degradation through erosion and desertification. The Ouergha catchment is highly vulnerable to this scourge. The objective of this study was to assess the sensitivity of land to degradation in the Ouergha catchment area. The MEDALUS approach, widely used in the Mediterranean region, was used to assess the sensitivity of soils to degradation/desertification. This approach integrates four indicators that strongly influence this phenomenon (climate, soil, vegetation and human pressure). The results show that more than half of the study area has a medium sensitivity of land to degradation. The critical areas represent 16.2% and correspond to bare land characterized by steep slopes and absence of vegetation. Low sensitivity areas occupy a limited proportion of 21.9% and correspond to wet summits and conserved forest areas. Climate change could lead to a further increase in areas susceptible to degradation.

Keywords

• Land degradation
• MEDALUS approach
• GIS
• Ouergha catchment
• Morocco

References

1. Al Karkouri, J., 2017. Les milieux montagneux marocains à l’épreuve du changement climatique (cas de la montagne rifaine). Hesperis Tamuda 52(1): 237–267. [in French]
2. Arrebei, N., Sabir, M., Naimi, M., Chikhaoui, M., Raclot, D., 2020. Assessment of soil erosion with RUSLE 3D and USPED in the Nekor Watershed (Northern Morocco). Open Journal of Soil Science 10(12): 631–642.
3. Balhane, S., Driouech, F., Chafki, O., Manzanas, R., Chehbouni, A., Moufouma-Okia, W., 2022. Changes in mean and extreme temperature and precipitation events from different weighted multi-model ensembles over the northern half of Morocco. Climate Dynamics 58(1–2): 389–404.
4. Bouabid, R., Rouchdi, M., Badraoui, M., Diab, A., Louafi, S., 2010. Assessment of Land Desertification Based on the MEDALUS Approach and Elaboration of an Action Plan: The Case Study of the Souss River Basin, Morocco. In: Land Degradation and Desertification: Assessment, Mitigation and Remediation. Zdruli, P., Pagliai, M., Kapur, S., Faz Cano, A. (Eds.). Springer, Dordrecht. pp.131-145.
5. Bouhata, R., Kalla, M., 2014. Mapping of environmental vulnerability of desertification by adaptation of the medalus method in the endoreic area of gadaine (eastern Algeria). Geographia Technica 9(2): 1–8.
6. Boutallaka, M., 2019. La vulnérabilité environnementale dans le bassin versant de l’Ouergha et l’augmentation de l’intensité des risques naturelles sous l’influence des variations climatiques. FLSH-Sais, USMBA, Fès. [in French]
7. Contador, J.F.L., Schnabel, S., Gómez Gutiérrez, A., Pulido Fernández, M., 2009. Mapping sensitivity to land degradation in Extremadura. SW Spain. Land Degradation and Development 20(2): 129–144.
8. Driouech, F., Stafi, H., Khouakhi, A., Moutia, S., Badi, W., ElRhaz, K., Chehbouni, A., 2021. Recent observed country-wide climate trends in Morocco. International Journal of Climatology 41(S1): E855–E874.

9. El Ouazani Ech-chahdi, K., El-Bouhali, A., Amyay, M., 2020. La cartographie et la caracterisation de la sensibilite a la desertification dans le bassin versant du haut ouergha (Rif central - Maroc) par l’approche medalus. Geomaghreb 16: 1–13. [in French]
10. Eekhout, J.P.C., de Vente, J., 2022. Global impact of climate change on soil erosion and potential for adaptation through soil conservation. Earth-Science Reviews 226: 103921.
11. El Mazi, M, Hmamouchi, M., Houari, A., 2021. Impact de l’évolution de l’utilisation des terres sur la dégradation des ressources en sols dans le Rif Central méridional, Maroc. Revue Marocaine des Sciences Agronomiques et Vétérinaires 9(4): 567–572. [in French]
12. El Mazi, M., Hmamouchi, M., Saber, E., Bouchantouf, S., Houari, A., 2022. Deforestation effects on soil properties and erosion : a case study in the central Rif , Morocco. Eurasian Journal of Soil Science 11(4): 275-283.
13. FAO, 2020. In Brief to The State of the World’s Forests 2022. Forest pathways for green recovery and building inclusive, resilient and sustainable economies. FAO (Food and Agriculture Organization of the United Nations), Rome, Italy. 28p. Available at [Access date: 04.12.2022]: https://www.fao.org/3/cb9363en/cb9363en.pdf
14. Francos, M., Úbeda, X., Pereira, P., 2019. Impact of torrential rainfall and salvage logging on post-wildfire soil properties in NE Iberian Peninsula. Catena 177: 210–218.
15. Ghanam, M., 2003. La desertification au Maroc – Quelle stratégie de lutte ? 2nd FIG Regional Conference, p.1/13, December 2-5, 2003. Marrakech, Morocco. [in French]
16. Janati Idrissi, A., 2010. Situations pluviometriques extremes et impacts engendres au maroc: cas de l’annee 2008 – 2009. Geomaghreb 6: 105–119. [in French]
17. Lahlaoi, H., Rhinane, H., Hilali, A., Lahssini, S., Moukrim, S., 2017. Desertification assessment using MEDALUS model in watershed Oued El Maleh, Morocco. Geosciences 7(3):50.
18. Lamqadem, A.A., Pradhan, B., Saber, H., Rahimi, A., 2018. Desertification sensitivity analysis using MEDALUS model and GIS: A case study of the Oases of Middle Draa Valley, Morocco. Sensors 18(7): 2230.
19. Laouina, A., Chaker, M., Aderghal., M., Machouri, N., 2013. Échelles d’évaluation de la dynamique et de la gestion des terres, du territoire social au bassin-versant expérimental. Publication de l’association de Recherche En Gestion Durable Des Terres « ARGOT», CERGéo, pp.118–145. [in French].
20. Maurer, G., 1968. Les montagnes du Rif central : Etude géomorphologique. Mohamed 5, Rabat. 499p. [in French].
21. Mharzi Alaoui, H., Assali, F., Rouchdi, M., Tahiri, D., Lahssini, S., Aafi, A., Moukrim, S., 2017. Mapping of fire intensity and of sensibility to crown fires in Mediterranean forests. Case of the province of Chefchaouen in northern Morocco. Revue d’Ecologie (La Terre et La Vie) 72(4): 387–409. [in French].
22. Mokhtari, N., Mrabet, R., Lebailly, P., Bock, L., 2013. Spatialisation des bioclimats, de l’aridité et des étages de végétation du Maroc. Revue Marocaine des Sciences Agronomiques et Vétérinaires 2: 50–66. [in French].
23. Mokhtari, N., 2016. Etude de la dynamique de la desertification dans le bassin versant de la Moulouya en integrant les donnees issues de la teledetection et les donnees socio-economiques. Thèse de doctoat, Université de Liège. 266p. [in French]. Available at [Access date: 04.12.2022]: https://hdl.handle.net/2268/198149
24. Prăvălie, R., Săvulescu, I., Patriche, C., Dumitraşcu, M., Bandoc, G., 2017. Spatial assessment of land degradation sensitive areas in southwestern Romania using modified MEDALUS method. Catena 153: 114–130.
25. Rabah, B., Aida, B., 2019. Adaptation of MEDALUS method for the analysis depicting land degradation in Oued Labiod Valley (Eastern Algeria). Advances in Remote Sensing and Geo Informatics Applications. CAJG 2018. El-Askary, H., Lee, S., Heggy, E., Pradhan, B. (Eds). Advances in Science, Technology & Innovation. Springer, Cham. pp. 281–285.
26. Salvati, L., Zitti, M., Perini, L., 2016. Fifty years on: Long-term patterns of land sensitivity to desertification in Italy. Land Degradation and Development 27(2): 97–107.
27. Sepehr, A., Hassanli, A.M., Ekhtesasi, M.R., Jamali, J.B., 2007. Quantitative assessment of desertification in south of Iran using MEDALUS method. Environmental Monitoring and Assessment 134(1–3): 243–254.
28. Thakkar, A.K., Desai, V.R., Patel, A., Potdar, M.B., 2017. Post-classification corrections in improving the classification of Land Use/Land Cover of arid region using RS and GIS: The case of Arjuni watershed, Gujarat, India. Egyptian Journal of Remote Sensing and Space Science 20(1): 79–89.
29. Tribak, A., 2020. Erosion and Flooding Risks in the Marly Basins of the Eastern Prerif Mountains (Morocco): A Response to Exceptional Climate Events or to Anthropogenic Pressure. Revista de Estudios Andaluces 40: 159–182.
30. Tribak, A., Baena-Escudero, R., Guerrero-Amador, I. C., Amhani, Z., Abahrour, M., El Garouani, A., Arari, K., 2021. Land use and hydric erosion assessment in a Mediterranean mountain environment: Case of Wadi Ourtza sub-basin (Eastern-Prerif, Morocco). Investigaciones Geográficas 76: 309–326. [in Spanish].
31. Trotta, C., Menegoni, P., Manfredi Frattarelli, F.M., Iannetta, M., 2015. Assessing desertification vulnerability on a local scale: the Castelporziano study case (central Italy). Rendiconti Lincei 26: 421–450.
32. Tucker, C.J., 1979. Red and photographic infrared linear combinations for monitoring vegetation. Remote Sensing of Environment 8(2): 127–150.