Paving the way for social learning when governance is weak: Supporting dialogue between stakeholders to face a groundwater crisis in Morocco

Approaches to improve the governance of social-ecological systems are difficult to define in situations where governance is weak, that is, involving limited interactions between the actors and weak management of natural resources. This article analyzes an action research process implemented in the Chaouia coastal region of Morocco, where weak governance of the social-ecological system led to a groundwater and agricultural crisis. A dialogue between local actors was set up with the aim of identifying strategies to address the crisis. First separately and then together, farmers' groups and staff members of public organizations analyzed the existing situation, scenarios for the future of the area, and strategies to cope with the crisis. Contrary to the expectations of the participants, farmers and staff members of public organizations had productive discussions. This approach clarified how social learning can be achieved and governance improved in this situation of weak governance. (Résumé d'auteur

Innovation et action collective : le semis direct des cultures pluviales au Moyen Sébou (Maroc)

Les exploitations familiales des pays du Sud, au foncier cultivable souvent limité, doivent pouvoir entretenir la fertilité de leurs terres si elles veulent améliorer leur productivité. L'agriculture de conservation et le semis direct sans travail du sol constituent des pratiques pouvant répondre à cet enjeu. Mais on constate qu'elles sont très peu adoptées par ce type d'exploitations. Cet article vise à décrire comment et pourquoi des agriculteurs de la région du Moyen Sébou au Maroc ont pu adopter le semis direct des cultures pluviales. Des entretiens avec les agriculteurs et quelques mesures au champ ont été réalisés. L'analyse du chantier de semis direct montre que l'agriculteur réalise une économie de temps et d'argent pour l'implantation du blé, comparativement au semis après préparation du sol. L'évolution du système de culture en semis direct vers un système d'agriculture de conservation avec couverture du sol est complexe et peu envisageable, du fait des enjeux économiques et sociaux autour de l'usage des résidus de cultures dans les exploitations de polyculture-élevage. Le renforcement de l'action collective apparaît important pour assurer la durabilité de cette expérience (meilleure organisation des chantiers, mise en place d'un suivi-évaluation, collaboration recherche-développement, etc.). (Résumé d'auteur

Assessing land degradation and sensitivity to desertification using MEDALUS model and Google Earth Engine in a semi-arid area in Southern Morocco: Case of Draa watershed

In Morocco, desertification affects a large area. It is more pronounced as the climate is arid with increasingly a long drought and poor soils that are highly vulnerable to erosion. In addition, the precarious living conditions of rural populations grow to overuse natural resources to meet their growing needs, which amplifies further environmental degradation. In this study, we have used the MEDALUS model to develop the sensitivity map of the Draa watershed. It is very characterized by its topographic, geomorphologic, and hydrological aspects and  bioecological qualities. The MEDALUS approach has allowed us to identify the different parameters and to calculate the four indexes needed for this algorithm. The sensitivity of desertification depends on the quality of soil, climate, vegetation, and management system.An aridity index featured the climate was established by using eight climate stations' data. The soil quality is determined by the texture maps, depth, slope, and parental materials from the geological maps of the investigated region. The quality of vegetation to combat desertification is performed by its resistance to drought, fire risk, ability to soil erosion, and plant cover calculated from the Sentibel-2 imagery and performed in Google Earth Engine (GEE). Finally, we had approached the last indicator by land-use intensity and poverty rate from the Census data. The sensitivity map was established by combining the four indexes. The results indicate that the most part of the Drâa watershed is threatened by desertification and represent low resistance to drought and low protection against erosion. Aridity affects more than 63% and this conditions make the area very vulnerable to desertification. These results could be help the decision-makers and policy to better manage and mitigate desertification impacts under global changes

Integrating Sentinel-2 Data and PAPCAR Model to Map Water Erosion: Case of Beni Boufrah Watershed

Water erosion causes significant economic losses linked mainly to the silting up of dams and losses in soil productivity, these consequences will increase if soil and water conservation actions associated with development actions are not undertaken. The present work aims to evaluate the water erosion in the basin of the Beni Boufrah located in the Northern part of Morocco. The hierarchy of this basin in plot according to the degrees and the tendencies of the erosion was made using the qualitative PAP/CAR approach (Programme d’Actions Prioritaires/Centre d’Activités Regionales) which is based on the integration of the factors influencing the water erosion, such as the slope, lithology and/or pedology, vegetation cover and land use. This work was conducted in three stages, the first one being predictive based on the analysis of the natural factors influencing water erosion and the processing of databases of developed maps. The second so-called descriptive stage is based on the mapping of different forms and processes of soil loss that occur in the study area. The last step, it allows the integration and the combination of the results of the two previous steps. Its purpose is to provide a precise cartographic product that reflects the reality of the state of soil degradation and the future evolution of erosion. The consolidated erosion map shows that more than half of the basin area (53%) is affected by medium-level erosion, 13% is affected by high erosion level, and 15 % is affected by low-level water erosion. Low-intensity erosion occurs along the river in areas where the slope and lithology favour runoff. The trend map is the final result of the integration phase, it describes erosion trends in the different parts of the basin and is, therefore, a tool to guide decisions on land use planning and tillage methods to limit the risk of water erosion in the basin. Keywords: Oued Beni Boufrah, water erosion, PAP/CAR, erosive states, erosion trend

The Porosity of Stabilized Earth Blocks with the Addition Plant Fibers of the Date Palm

This work is an experimental study to analyze the physical behavior of Stabilized Earth Block (SEB) and reinforced with Plant Fibers of the Date Palm (PFDP). This is part of the valorization of local building materials (earth, fiber) and contributes to reduce the price of housing. Initially, physical tests (Density, Total Water Absorption, and Capillary Absorption) were carried out in preparation for the porosity study. However, the main objective of this study is the investigation of porosity phenomenon using several methods as well as the total porosity estimation, the total volume porosity in water and Open porosity methods, where the mechanical resistance is also considered.  In order to improve the stabilized earth block porosity analyses, various dosages are proposed for cement, lime and fiber. Thus (0%, 5%, 10%) of cement, (0%, 5%, 10%) of lime and the combination (5% cement + 5% lime) with (0%, 0.25%, and 0.5%) of fibers for each composition. The experimental results showed that the addition of fibers increases the porosity of the stabilized earth block proportionally and an increasing quantity of the stabilizer reduces the porosity of the SEB, cement is also more effective at closing pores than lime. Moreover, the compositions 10% cement and the mixture of 5% cement + 5% lime with 0% fiber showed a good results of porosity, for this reason they can be used as a durable building material and good resistance to natural and chemical aggression

Effet de dopage sur une structure à base du graphène passivée: Graphène nanoruban

Le dopage des matériaux est une méthode qui permet de contrôler les propriétés d’un matériau. Pour concevoir une structure avec des propriétés structurale, électronique et magnétique, on doit faire recours aux nouveaux types de matériaux aux propriétés exceptionnelles. Les nanostructures à base de graphène sont des bons candidats pour concevoir une nouvelle générationde matériaux. Les méthodes ab-initio, se basant sur la DFT, sont les plus appropriées pour étudier ces nano-systèmes. Le principe de base consiste d’abord à étudier une structure, dopée avec trois métaux de transition, ce dopage fait varier d’une manière importante les propriétés citées. Une analyse comparative entre différentes structure de graphène nanoruban de type armchair passivée dopées avec Au, Ag et Fe. Enfin nous avons généré les pseudo-potentiels des dopants. Les calculs sont réalisés à l’aide du logiciel SIESTA

Utjecaj tehnologije raspršivanja na performanse apsorbera u H2O/LiBr apsorpcijskom rashladnom uređaju

For major thermal engines used in industrial sectors, the use of chillers has been growing steadily over the previous decades. Indeed, this is linked strongly to their large energy performance despite their investment costs, which are still high, in particular for low powers. Performance coefficients for absorption chillers are relatively low, and their profitability depends on the costs of the main equipment and more particularly on the price of the absorber. Several studies focusing on the development of mass contactors are underway with the principal objective of further improving their performance of mass and energy transfer. Relating to the mass and heat transfer, it is specified that the contact between the phases in circulation is ensured by different types of contactors. The transfer performance is correlated with the heat and mass transfer coefficient on the one hand, and the specific exchange area, i.e., the exchange area per unit volume of the contactor on the other hand. These contactors are distinguished by their mode of contact between phases (bubbling, spraying, falling film, etc.). While the exchange coefficient depends on the hydrodynamics regime in the contactor (flow regime and physicochemical properties of phases), the specific exchange area is dictated by its operating mode. Any limitation of its use for a specific application (physicochemical phenomena, such as crystallisation, deposited dust, etc.) requires research and development of better devices more adapted. Moreover, the most used contactors in chemical engineering are plate columns, packed columns, falling film columns, spray columns, etc. In order to intensify exchanges, a new absorber of the pulverised type is to be explored in relation with the physicochemical properties of the phases, and of their hydrodynamic flow conditions in the sprayed column. Therefore, an experimental study of the influence of operating variables (nozzle diameter, fluids flow rate, their concentrations, size of droplets, etc.) on the overall coefficient of mass transfer in gaseous phase in the absorber of the absorber chiller was conducted. After having fixed the pressure in the absorber, the first part of the study allowed developing new correlations linking the experimental results of the KG ∙ a to all operating variables (L, C, dd, etc.). The second part was devoted to the simulation of the absorption chiller functioning by introducing the concept of energy and exergy yields based on the mass transfer correlations.Posljednjih desetljeća vidljiv je stalan porast upotrebe rashladnih uređaja kod glavnih toplinskih motora koji se upotrebljavaju u industrijskim sektorima. Koeficijenti učinka apsorpcijskih rashladnih uređaja relativno su niski, a njihova isplativost ovisi o troškovima glavne opreme, točnije o cijeni apsorbera. U tijeku je nekoliko studija razvoja kontaktora masa usmjerenih na poboljšanje prijenosa tvari i energije u kontaktorima. Vezano uz prijenos tvari i topline, specificirano je da se kontakt između cirkulirajućih faza ostvaruje različitim tipovima kontaktora. Učinak prijenosa koreliran je s koeficijentom prijenosa tvari i topline s jedne strane te specifičnom površinom izmjene, tj. površinom izmjene po jedinici volumena kontaktora, s druge strane. Kontaktori se razlikuju po načinu kontakta faza (mjehurići, raspršenje, padajući film, itd.). Dok koeficijent izmjene ovisi o hidrodinamičkom režimu u kontaktoru (režim protoka i fizikalno-kemijska svojstva faza), specifična površina izmjene ovisi o njegovu načinu rada. Ograničenje njegove uporabe na neku određenu primjenu (fizikalno-kemijske pojave poput kristalizacije) zahtijeva istraživanje i razvoj uređaja koji bi više bili prilagođeni spomenutoj primjeni. Štoviše, najčešće upotrebljavani kontaktori u kemijskom inženjerstvu su kolone s pliticama, kolone s punilima, kolone s padajućim filmovima, kolone za raspršivanje, itd. S ciljem povećanja izmjena, istražit će se novi praškasti apsorber i to s obzirom na fizikalno-kemijska svojstva faza i njihove hidrodinamičke uvjete strujanja u koloni za raspršivanje. Stoga je provedeno istraživanje utjecaja radnih varijabli (promjera mlaznice, protoka fluida, koncentracije fluida, veličine kapljica, itd.) na ukupni koeficijent prijenosa tvari u plinovitoj fazi u apsorberu rashladnog uređaja. Nakon fiksiranja tlaka u apsorberu, prvi dio istraživanja omogućio je razvoj novih korelacija koje povezuju eksperimentalne KG ∙ a rezultate sa svim radnim varijablama (L, C, dd, itd.). Drugi dio bio je posvećen simulaciji rada apsorpcijskog rashladnog uređaja uvođenjem koncepta energetskih i eksergijskih prinosa temeljenih na izrazima za prijenos tvari

Assessing the Impacts of Different Initiatives on the Rehabilitation of Pastoral and Silvopastoral Ecosystems: Big Data Oriented Approach

Moroccan forests, through the provision of goods and ecosystem services, underpins benefits to local communities and play a crucial role for rural area development. The legal framework recognizes to people, living near public forests, the right to graze their domestic livestock. Over the years, the grazing pressure is at levels far beyond the forestland’s carrying capacity throughout the country. Such pressure has been demonstrated as the main cause of forest cover loss and land degradation in Morocco and still threatening the sustainability of forests. To reduce the heavy grazing pressure on forest ecosystems and ensure their regeneration, several initiatives have been conducted such as the program of compensation for forest areas closed to grazing (CFCG), initiated by Moroccan forestry department. Socio-economic impact assessment of this mechanism was presented within several studies but its effectiveness for forest rangeland rehabilitation remains scarce and very spatially limited. To deal with this concern and to assess vegetation dynamics through various spatial and temporal scales, parcels concerned by CFCG and others within similar conditions was chosen. Time series of remotely sensed spectral indices at each parcel was used for vegetation cover dynamics assessment. Google Earth Engine platform (GEE) was used as computing plateform. As result, the spectral indices trends shown a long-lasting degradation tendency in areas planted without compensation compared to those concerned by CFCG. Such results were also verified using aerial images covering the analyzed parcels. As conclusion, within comparable conditions, CFCG improved vegetation cover trends. The use of GEE Platform simplified the process of treatment of remote sensed imagery and made it easy to assess the state of the vegetation and will be of great use in assessing the impacts of different programs and initiatives on the restoration of pastoral and silvopastoral ecosystems