Landscape analysis and suitability of CSL systems - D7.1

This work characterizes the landscape and proposes mapping of CSL suitability for the SustainSahel sites. Rainfall, elevation, soil groups, soil organic carbon and land cover-tree/shrub cover were mapped at the regional scale (Senegal, Mali, Burkina Faso) and at the site scale (i.e. 7 study sites). Data were obtained from existing databases (e.g., WaPOR, ISRIC, TAMSAT) and processed with R and Qgis software. The results show that averaged annual rainfall varies from 400 mm in Ouarkhokh to 900 mm in Sikasso. The elevation varies from less than 150 m in Senegal to more than 500 m in Burkina Faso. The dominant soil classes in the region are Acrisols, Luvisols, arenosols, plinthosols, leptosols and vertisols. Land cover is dominated by rain-fed crops and shrublands. Waterholes, Built-up and unclassified vegetation types are present in some areas. The amount of soil organic carbon ranges from 0 to 34 g/kg. The lowest values were found in Senegal at Niakhar, Ouarkhokh and Koussanar sites, while the highest values were observed at Sikasso and Koulikoro sites in Mali. At Burkina Faso sites, the intermediary amount of carbon ranged from 2 to 24g/kg. A provisional mapping of CSL systems in the study sites was proposed. It is based on the list of woody species identified from the literature and the Work Package 4 second deliverable and on average values of rainfall, aboveground biomass, elevation, soil organic carbon and tree-shrub cover. Two tables were produced, one on the presence of species according to the sites and another on the average values of environmental parameters according to the different sites. A Correspondence Factor Analysis (CFA) and a Principal Component Analysis (PCA) were respectively performed using the R software to show the similarities between sites with respect to species on the one hand and environmental variables on the other hand. The results showed that species are concentrated in sites with high values of elevation, soil organic carbon, aboveground biomass, tree-shrub cover and precipitation. The preliminary analysis presented in this internal report will be further refined in coming months using additional data from WP4, 5 and 6, outputs from the LUCIA model and also advanced methods based on remote sensing technologies.