Sahara and Sahel Observatory

Aims: To contribute to knowledge of the health quality of food sold near schools in N'Djamena, Chad, in order to ensure that students have healthy food. Study Design: Cross-sectional descriptive study based on analyses of collected samples and interpretations of the results. Place and Duration of Study: The study was carried out from January 2023 to December 2024 in five (5) districts of the city of N'Djamena in Chad. Methodology: Microbiological analyses were carried out on samples through standard methods in microbiology. A total of 79 samples were taken, divided between Sandwiches (37), Danwaké (25) and Alelés (17). The germs counted were total mesophilic aerobic flora (FAMT), total coliforms, yeasts and molds, Staphylococcus and Escherichia coli. Results: The results revealed that for sandwiches, 81.2% and 88.9% to 100% of the samples analyzed were non-compliant with respect to total aerobic mesophilic flora and total coliforms respectively. For E. coli, 68.8% of the standard sandwich samples were non-compliant and 100% of the peanut sauce and eggplant sandwich samples were highly loaded with Staphylococcus as well as yeasts and molds. Analysis of the Danwaké samples showed non-compliant results for all germs with high percentages particularly for coliforms (86%) followed by staphylococci (76%). In the Alelés, these are also the germs that are regularly found in samples with non-compliance rates of 62.5% and 75% respectively for staphylococci and yeasts and molds. Conclusion: The presence of these germs in non-compliant proportions in Sandwiches, Danwaké and Alelés sold near schools constitutes a significant health hazard that deserves awareness among stakeholders in order to offer young students healthy foods to guarantee their health.

Aims: The aim of this study was to determine the factors behind the increase in the number of cases of typhoid fever in the commune of Doba. Place and Duration of Study: Our study was carried out in the District and Provincial hospital and the Christian Assemblies in Chad (ACT) health center of Doba, from July to August 2022. Methodology: A total of 756 Widal and Félix tests according to the slide agglutination technique described by Raobijaona and Ranaivo-Harisoa were carried out in three health facilities in order to confirm the reliability of the test within these facilities. Surveys, using survey forms, were carried out in 120 households, with 95 households participating in our study. Results: The results showed a fairly high typhoid fever prevalence rate (72.52%), with all households surveyed (100%) using self-medication antibiotics. We also noted a high frequency of antibiotic use without a doctor's prescription. Non-compliance with hygiene and sanitation rules was noted in the majority of households (80%), which ate food without carefully washing their hands with soap and water. Most of the households surveyed (52%) had no toilet, which encourages open defecation. Conclusion: Despite its unreliability, the Widal and Félix serodiagnosis is the test frequently requested and carried out. Failure to comply with hygiene measures and excessive self-medication, at the root of the selection of resistant bacteria, have been partly identified as factors that have contributed to the increase in the number of cases of typhoid fever in Doba.

The availability of current land cover and land use (LCLU) information for monitoring the status of land resources has considerable value in ensuring sustainable land use planning and development. Similarly, the need to provide updated information on the extent of LCLU change in West Africa has become apparent, given the increasing demand for land resources driven by rapid population growth. Over the past decade, multiple projects have been undertaken to produce regional and national land cover maps. However, using different classification systems and legends has made updating and sharing land cover information challenging. This has resulted in the inefficient use of human and financial resources. The development of the Land Cover Meta Language (LCML) based on International Organization for Standardization (ISO) standards offers an opportunity to create a standardized classification system. This system would enable easier integration of regional and national data, efficient management of information, and better resource utilization in West Africa. This article emphasizes the process and the need for multistakeholder collaboration in developing a standardized land cover classification system for West Africa, which is currently nonexistent. It presents the survey data collected to evaluate historical, current, and future land cover mapping projects in the region and provides relevant use cases as examples for operationalizing a standardized land cover classification legend for West Africa.

RICOWAS, the largest SRI scaling-up project to date, will be implemented over four years in 13 West African countries, starting in January 2023. RICOWAS can be considered a follow-on project to the SRI-WAAPP project, which was implemented from 2014-2016 and reached 50,048 farmers growing rice using the SRI method at 1,088 sites on 13,944 hectares across 13 countries, with 56% and 86% SRI yield increases for irrigated and rainfed lowland systems, respectively, over conventional rice production. The objective of RICOWAS is to improve climate resilience and increase the rice system productivity of smallholder rice farmers across West Africa using a climate-resilient rice production approach. The project aims to reach at least 153,000 rice growers with indirect benefits to an estimated 1.5 million people. Given the highly diverse nature of rice systems and climate zones in West Africa, RICOWAS will apply the conceptual framework for SRI with four interactive crop production principles, i) encourage early and healthy plant establishment, ii) minimize competition among plants, iii) build up fertile soils rich with organic matter and beneficial soil biota, and iv) manage water carefully to avoid both flooding and water stress. These principles remain the same no matter where SRI is applied and provide the foundation for adaptation to local conditions. With SRI at the center, RICOWAS additionally integrates agro-ecozone specific Sustainable Land and Water Management (SLWM) practices to maximize the adaptation potential of the vulnerable rice production systems throughout West Africa, calling the new approach Climate-Resilient Rice Production (CRRP).

Due to the semi-arid nature of the Sahelian countries in Africa, irrigation infrastructures are essential in supporting the improvement of agricultural production. Their proper operation is, therefore, a key indicator for the sustainable development of agriculture in this region. However, there is a lack of critical assessment on the operating state of these hydro-agricultural facilities in Burkina Faso. In this study, we applied a multiple correspondence analysis (MCA) to 4070 hydro-agricultural facilities from 1950 to 2020 and classified them according to the Permanent Interstate Committee for Drought Control in the Sahel’s (CILSS) typology classification system (Type 1 to Type 5). The MCA made it possible to see the relationships between a development typology and variables such as “functionality”, “condition of the development”, or “year of construction”. The results indicate that the irrigated lands with surface areas of less than 100 ha, which were funded by the government or organizations (associations, NGOs) and managed by local communities, are the least functional ones and in bad condition. Their dysfunction indeed conceals deep-seated causes that have not yet been resolved as the infrastructures keep on deteriorating. Therefore, establishing a sustainable and efficient management system for these agricultural infrastructures is imperative. The findings of this study can be used as a practical decision-making tool for implementing agricultural policies in the Sahel region.

When in 1975 Spain leaves to its fate the inhabitants of the former Spanish province of Western Sahara, most of the Saharawi population has to flee their homes chased by the armies of Morocco and Mauritania in the operation known as “Ecouvillon” while the civilian population marched to Saharaui territory in "The Green March" .In this flight to the desert find refuge in an inhospitable territory of the Algerian Hamada where, located in four camps, declare the Sahrawi Arab Democratic Republic (SADR), organizing basic services that allow the survival of the population as well as the possibility of return and government of the territory of Western Sahara in the future. Within the hardness of the situation emerges something exceptional and it is the main axis of this article. The Saharawi people are able to create in the desert refugee camps an educational system that reduces illiteracy in the population as a whole and in childhood in particular. They have been able to organize an educational system in which practically 100% of children are in school, reducing the illiteracy of 90% of the population, in colonial times, to data similar to those of developed countries. In the education of the camps you can study children's education, primary, secondary and also vocational training. In this article we will go deeper into the main characteristics and difficulties of a structured educational system practically without economic resources, but what represents a great commitment to education as a form of struggle, social and political progress. We will also analyze the role of the Spanish Government as a donor of humanitarian aid to these people, as well as its political responsibility in a conflict that has been open for more than 40 years, with Western Sahara being the only territory in the world pending decolonization.

A partir de la description formelle des concepts « OSAGE » (Observatoire Scientifique en Appui aux GEstionnaires de territoire) dans ses dimensions scientifique, technique et organisationnelle, nous analysons l’experience concrete et specifique de l’observatoire ROSELT/OSS (Reseau d’observatoires de surveillance ecologique a long terme/Observatoire du Sahara et du Sahel) menee depuis 1992 en matiere de lutte contre la desertification dans le circum-Sahara. Cette confrontation modele abstrait/modele concret (ou « instance ») permet de tester la validite du modele abstrait (OSAGE), mesurer sa richesse et ses difficultes de mise en œuvre et l’enrichir, tout en offrant un cadre formel pour analyser ROSELT/OSS et mesurer son niveau de conformite au modele OSAGE.

The multi-layered Jeffara de Gabes aquifer system is greatly influenced by tectonics. This system is limited at the base and laterally by evaporite layers and has lateral contacts with the sebkhas (salt flats). The groundwater in this aquifer is characterized by high salinity (3–10 g L-1). Multivariate statistical analysis and a geochemical approach were applied to determine the influence of the evaporite layers and sebkhas on the hydrochemical quality of the Jeffara de Gabes aquifer, and to understand the processes governing its salinity. According to these methods, and based in part on the Sr2+/Ca2+ ratio, it is demonstrated that the strong salinity of the groundwater is due to interactions between water and the evaporite layers that act as a substratum of this aquifer, as well as saltwater intrusion from the sebkhas. Moreover, the medium- to poor-quality groundwaters are characterized by geochemical interactions: cationic exchange and the precipitation/dissolution process of minerals in the aquifer formations.Editeur Z.W. KundzewiczCitation Ben Alaya, M., Zemni, T., Mamou, A. et Zargouni, F., 2014. Acquisition de salinité et qualité des eaux d’une nappe profonde, Tunisie: approche statistique et géochimique. Hydrological Sciences Journal, 59 (2), 395–419.

Environmental monitoring and evaluation (M&E) systems are indispensable tools for sustainable land management, especially in dry and fragile ecosystems. The reporting and dissemination of its products and indicators are the key roles to perform their missions. Furthermore, the overall success of such multilateral projects and networks depends on well-organized infrastructures for spatial data management. A spatial data infrastructure (SDI) is an efficient framework to centralize the management of spatial data and information related to multilateral projects for the best sharing and exchange between partners and stakeholders in order to ensure that they are interactively connected to use the data efficiently and in a flexible manner. This paper outlines the work undertaken in partnership between the Geography and GIS Department of the Faculty of Arts, King Abdulaziz University, Saudi Arabia Kingdom, the Geomatics, Earth and Land Settlement Branch of the Department of Geology, Faculty of Sciences of Tunis, Tunis El Manar University, Tunisia, and the Sahara and Sahel Observatory OSS which is an intergovernmental organization, in order to build a Spatial Data Infrastructure (SDI) for the ROSELT/OSS program (Long-Term Environmental Monitoring Observatories Network in the Circum-Sahara of the Sahara and Sahel Observatory). This SDI is entirely developed using Open Source technologies and the extensive suite of OGC (Open Geospatial Consortium) standards and specifications, to enable interoperability among and between its different components.