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

Participatory management of rangeland hydrology – a new socio-ecological technology to effectively adapt to and mitigate climate change: case from Morocco

Les zones arides du Maroc pays plus de 90 % de la superficie terrestre ; des précipitations faibles et irrégulières et un potentiel élevé d'évaporation à des déficits hydrauliques extrêmement élevés dans cette zone. Ces phénomènes ont fortement impacté l'hydrologie des parcours et le pastoralisme nomade et transhumant. Pour s'adapter à ce déficit hydrique prédominant, les habitants de ces zones ont développé deux modes de vie, qui incluent la mobilité des ménages et du bétail : (i) un mouvement pendulaire pour la transhumance saisonnière entre les montagnes et leurs plaines limitrophes ; et (ii) une mobilité nomade aléatoirement régulée par la fréquence sporadique des pluies et donc la disponibilité de l'eau.Dans les deux cas, cette mobilité est contrôlée par le degré d'aménagement des routes, mais elle assure également une gouvernance participative de l'accès à l'eau pour le bétail. Par exemple, les communautés pastorales usent d'abord des routes aux eaux éphémères, tout en économisant des sources d'eau pérennes ou semi-pérennes pour des périodes de sécheresse de longue durée. Pour la pénurie d'eau, les nomades et les transhumants souvent la taille des troupeaux et se tournent temporairement vers des activités complémentaires telles que le commerce, l'artisanat, le salarié et l'engagement dans les services publics.Les conservatrices de gestion des parcours et de l'eau pratique ont progressivement décliné suite aux tendances et mondiales de sédentarisme, d'extension urbaine et à l'émergence de nouvelles activités telles que l'irrigation intensive, l'industrie et le tourisme. Face à cette situation, diverses organisations de développement visent le rétablissement des pratiques traditionnelles locales de conservation et de gestion participative de l'eau. La récupération des eaux de pluie ainsi que des aménagements hydrauliques, des services de stockage et de réservoir pour les populations isolées sont mis en place en plusieurs points le long des routes nomades.En outre, de nouvelles opportunités de scolarisation ont ouvert des opportunités d'emploi et des revenus supplémentaires provenant des activités agricoles. Dans ce cadre, un suivi transdisciplinaire de l'aménagement des parcours par télédétection ainsi que des indicateurs biophysiques et socio-économiques ont été mis en place. Dans ce travail, nous présentons une analyse intégrée des systèmes de gestion hydrologique des zones arides marocaines en relation avec l'adaptation pastorale au changement climatique. un suivi transdisciplinaire de l'aménagement des parcours par télédétection ainsi que des indicateurs biophysiques et socio-économiques ont été mis en place. Dans ce travail, nous présentons une analyse intégrée des systèmes de gestion hydrologique des zones arides marocaines en relation avec l'adaptation pastorale au changement climatique. un suivi transdisciplinaire de l'aménagement des parcours par télédétection ainsi que des indicateurs biophysiques et socio-économiques ont été mis en place. Dans ce travail, nous présentons une analyse intégrée des systèmes de gestion hydrologique des zones arides marocaines en relation avec l'adaptation pastorale au changement climatique

Data for wetlandscapes and their changes around the world

Geography and associated hydrological, hydroclimate and land-use conditions and their changes determine the states and dynamics of wetlands and their ecosystem services. The influences of these controls are not limited to just the local scale of each individual wetland but extend over larger landscape areas that integrate multiple wetlands and their total hydrological catchment – the wetlandscape. However, the data and knowledge of conditions and changes over entire wetlandscapes are still scarce, limiting the capacity to accurately understand and manage critical wetland ecosystems and their services under global change. We present a new Wetlandscape Change Information Database (WetCID), consisting of geographic, hydrological, hydroclimate and land-use information and data for 27 wetlandscapes around the world. This combines survey-based local information with geographic shapefiles and gridded datasets of large-scale hydroclimate and land-use conditions and their changes over whole wetlandscapes. Temporally, WetCID contains 30-year time series of data for mean monthly precipitation and temperature and annual land-use conditions. The survey-based site information includes local knowledge on the wetlands, hydrology, hydroclimate and land uses within each wetlandscape and on the availability and accessibility of associated local data. This novel database (available through PANGAEA https://doi.org/10.1594/PANGAEA.907398; Ghajarnia et al., 2019) can support site assessments; cross-regional comparisons; and scenario analyses of the roles and impacts of land use, hydroclimatic and wetland conditions, and changes in whole-wetlandscape functions and ecosystem services

Priorities and interactions of Sustainable Development Goals (SDGs) with focus on wetlands

Wetlands are often vital physical and social components of a country's natural capital, as well as providers of ecosystem services to local and national communities. We performed a network analysis to prioritize Sustainable Development Goal (SDG) targets for sustainable development in iconic wetlands and wetlandscapes around the world. The analysis was based on the information and perceptions on 45 wetlandscapes worldwide by 49 wetland researchers of the GlobalWetland Ecohydrological Network (GWEN). We identified three 2030 Agenda targets of high priority across the wetlandscapes needed to achieve sustainable development: Target 6.3-'Improve water quality'; 2.4-'Sustainable food production'; and 12.2-'Sustainable management of resources'. Moreover, we found specific feedback mechanisms and synergies between SDG targets in the context of wetlands. The most consistent reinforcing interactions were the influence of Target 12.2 on 8.4-'Efficient resource consumption'; and that of Target 6.3 on 12.2. The wetlandscapes could be differentiated in four bundles of distinctive priority SDG-targets: 'Basic human needs', 'Sustainable tourism', 'Environmental impact in urban wetlands', and 'Improving and conserving environment'. In general, we find that the SDG groups, targets, and interactions stress that maintaining good water quality and a 'wise use' of wetlandscapes are vital to attaining sustainable development within these sensitive ecosystems. © 2019 by the authors

Correction: Priorities and interactions of sustainable development goals (SDGs) with focus on wetlands. Water 2019, 11, 619 doi: 10.3390/w11030619

10.3390/w12010088Water (Switzerland)1218

Évaluation de la production de des cultures alternatives sous Nano-irrigation au Maroc (Cas des cultures de Quinoa et Panic bleu sous Moistube)

Moistube technology, widely known as nano-irrigation, is starting to gain popularity lately in Morocco compared to other buried irrigation systems made up of porous tubes. However, the technology remains unknown with installation difficulties for professionals, and only a few demonstration trials, and rarely scientific trials are conducted to demonstrate the potential to further minimize water consumption compared to drip irrigation. In this study, we compared the nano-irrigation (Moistube) and drip systems in terms of water-saving and their effect on the growth of two alternative crops tolerant to salt and water stress, “Quinoa with a single growth cycle " and " the Blue Panicum with several growth cycles". A factorial design was carried out for each of the two crops. Two different irrigation systems were installed for each crop, the standard drip system and the Moistube irrigation system (n = 12). For quinoa, there was no significant difference between the applied irrigation water amounts and shoot dry biomass under nano irrigation and drip irrigation while registering improvement in grain yield under nano irrigation system. For the blue panicum, the water savings, until harvest, were 26%, 29%, and 19% higher under the nano-irrigation than with the drip irrigation system for the 3rd, 4th, and 5th growth cycles respectively. However, the dry matter biomass was not significantly different between the nano irrigation and drip irrigation treatments. Insofar as the variations in water requirements on the scale of a growth cycle, the number of days between refills of the nano-irrigation tank increased over time to stabilize at an average of 6 days in summer and 10 days in winter. These results suggest that the nano-irrigation system could be efficient in terms of water-saving for crops with multiple growth cycles such as blue panicum. This leads us to assume that further water saving could be achieved particularly for tree crops with large lateral row spacings. The findings also suggest an earlier production under nano irrigation compared to drip irrigation. At last, we recommend the installation of the nano system during rainy periods when the soil is wet, and the soil suction forces are low which would increase the duration of irrigation of a filled reservoir and would allow important water savings during the crop growth cycle.La technologie Moistube, largement connue sous le nom de nano-irrigation, commence à gagner en popularité ces derniers temps au Maroc par rapport à d'autres systèmes d'irrigation enterrés constitués de tubes poreux. Cependant, cette technologie reste encore méconnue avec des difficultés d'installation par les professionnels, et seuls quelques essais de démonstration, et rarement des essais scientifiques sont menés pour démontrer le potentiel de minimiser davantage la consommation d'eau par rapport à l'irrigation goutte à goutte. Dans cette étude, nous avons comparé les systèmes de nano-irrigation (Moistube) et de goutte-à-goutte en termes d'économie d'eau et leur effet sur la croissance de deux cultures alternatives tolérantes au stress salin et hydrique, le « Quinoa à cycle de croissance unique » et « le Blue Panicum avec plusieurs cycles de croissance". Un plan factoriel a été réalisé pour chacune des deux cultures. Deux systèmes d'irrigation différents ont été installés pour chaque culture, le système de goutte à goutte ordinaire et le système d'irrigation Moistube (n = 12). Pour le quinoa, il n'y avait aucune différence significative entre les quantités d'eau d'irrigation appliquées et la biomasse sèche de la partie aérienne sous nano irrigation et irrigation goutte à goutte et une nette amélioration du rendement en grains sous système de nano irrigation. Pour le bleu de panicum, les économies d'eau, jusqu'à la récolte, étaient de 26%, 29% et 19% plus élevées sous la nano-irrigation qu'avec le système d'irrigation goutte à goutte pour les 3eme, 4eme et 5eme cycles de croissance respectivement. Cependant, la biomasse de la matière sèche n'était pas significativement différente entre les traitements de nano irrigation et d'irrigation goutte à goutte. En considérant les variations des besoins en eau à l'échelle d'un cycle de croissance, le nombre de jours entre remplissages du réservoir de nano-irrigation a augmenté au cours du temps pour se stabiliser à une moyenne de 6 jours en été et 10 jours en hiver. Ces résultats montrent que le système de nano-irrigation pourrait être efficace et efficient en termes d'économie d'eau pour les cultures à cycles de croissance multiples comme le bleu de panicum. Ceci nous amène à supposer qu'une plus grande économie d'eau pourrait être réalisée en particulier pour les cultures arboricoles avec de grands espacements entre lignes. Les résultats suggèrent également une production plus précoce sous nano irrigation par rapport à l'irrigation goutte à goutte. Enfin, nous recommandons l'installation du nano système pendant les périodes pluvieuses lorsque le sol est humide et les forces d'aspiration du sol sont faibles ce qui augmenterait la durée du réservoir à irriguer et permettrait une économie d'eau considérable pendant le cycle de croissance des cultures

Hybrid Fuzzy AHP and Frequency Ratio Methods for Assessing Flood Susceptibility in Bayech Basin, Southwestern Tunisia

Flash floods are a significant threat to arid and semi-arid regions, causing considerable loss of life and damage, including roads, bridges, check dams and dikes, reservoir filling, and mudslides in populated areas as well as agricultural fields. Flood risk is a complex process linked to numerous morphological, pedological, geological, anthropic, and climatic factors. In arid environments such as where Bayech basin is located in southwestern Tunisia, the hydrometric data are insufficient due to the absence of measuring points. Using the hybrid fuzzy Analytical Hierarchy Process (F-AHP) and the frequency ratio statistical methods, this study aims to map flooding risks in an ungauged basin that is extremely prone to flooding. Data related to soil texture, slope, land use, altitude, rainfall, drainage density, and distance from the river were used in the risk analysis. The obtained flood risk maps from both F-AHP and FR models were validated on the basis of the Receiver Operating Characteristic (ROC), the Area Under the Curve (AUC), and the inventory map. Results revealed that areas of high and very high susceptibility to flooding are mainly located in the downstream part of the basin, where the town of Gafsa is located. Other upstream sites are also at risk. In this basin, slope is predominantly behind runoff accumulation, whereas soil type plays a major role in amplifying waterproofing and therefore overflow. The results derived from both methods clearly demonstrate a viable and efficient assessment in flood-prone areas. The F-AHP and FR methods have ROC values of 95% and 97%, respectively. Considering these results in the decision-making process, these outputs would enable the implementation of the necessary measures to mitigate flood risk impacts ensure sustainable development along with an effective management in Tunisian arid environments, for the well-being of local communities at risk