Spatialisation des bioclimats, de l’aridité et des étages de végétation du Maroc

Abstract

The objective of this study was to compare and analyze the spatial extent and geographic location of aridity and bioclimatic zones in Morocco and their limitations using different indices used in North Africa and elsewhere in the Mediterranean region. The analysis was based on the use of data from the WORLDCLIM database, spatialization through GIS techniques, and the distribution of different plant species. Hence, the bioclimatic zones were characterized by spatial approach using Emberger pluviothermic Chart. The results showed that according to the different indices of aridity, the hyper-arid areas in Morocco represent 45 to 55% of the country. The spatial distribution of rainfall showed that 48% of Moroccan territory receives less than 100mm annually, while areas where the precipitation is more than 600mm do not exceed 6%. Arid, semi-arid and sub-humid zones potentially affected by desertification represent 42%. The comparison of different indices used showed that De Martonne aridity index seems to be satisfactory for regional studies. The derivation of the bioclimatic zones map, based on the diagram of Emberger, (Q2 and Tmin) showed the existence of five main types of climates in Morocco, ranging from humid to peraride. The per-humid bioclimatic stage is not significant and is limited to the crest of Rif mountains (<5km²). The thermal variations from "Temperate" to "Very hot" represent more than 70% of the territory.