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

Hydro-climate characteristics of the karst system of Wintimdouine cave (Western High Atlas, Morocco): monitoring and implications for paleoclimate research

The cave of Wintimdouine, located in a semi-arid context in Morocco, comprises the longest-known underground river in Africa. This cave system faces many challenges related to anthropogenic and climate forcing. Therefore, it has become necessary to understand the functioning of the aquifer system of Wintimdouine and how the regional climate affects its environment. Herein, we used different approaches based on a 4-year monitoring to shed light on the hydro-chemical behavior and stable isotopes contents of water samples, climate settings inside the cave, and moisture trajectory analyses. Chemical analyses show that groundwater is dominated by bicarbonate and calcite with an excellent chemical quality of cave water, suggesting an active recharge of the aquifer system which constitutes the main drinking source in the region. The stable isotope composition is consistent among rainwater, cave water and groundwater samples outside the cave. The evaporation effect is not significant, probably due to the rapid infiltration of surface water to the epikarst and vadose zone, which is favored by the abundance of exo-karstic forms above the cave. The cave monitoring indicates that periods of increased drip water flow induce an increase of temperature and humidity inside the cave, mainly during the spring-summer season. The high relative humidity and the relatively stable temperature favor the carbonate deposition under equilibrium conditions with drip water inside the cave. Furthermore, the moisture trajectory analysis confirms that the predominant air masses reach Wintimdouine cave from the North Atlantic Ocean, consistent with the mean deuterium-excess value of rainwater samples and the NAO-related westerly winds. Hence, we highlight the potential of Wintimdouine speleothem delta O-18 as a proxy of past climate variability at a regional scale

GIS-Based Land Suitability and Crop Vulnerability Assessment under Climate Change in Chtouka Ait Baha, Morocco

Agriculture plays a crucial role in the economic development in Morocco, contributing to 14% of the national gross domestic product. However, this sector is facing various challenges, including climate change. This study aims to assess relevant indicators that may affect land suitability, water demand, and crop growing season duration under climate change. Further, it may be used as a decision support tool in the Chtouka area known for its irrigated agriculture. The approach proposed, the spatial distribution of land based on suitability, is founded on the multiple-criteria decision-making method of four parameters; soil texture, temperature, land use, and slope. The duration of the length of crop season was simulated using the concept of growing degree days. The projection of land suitability for 2031–2050 indicated an important decrease of 12.11% of “highly suitable” agricultural land under the RCP4.5 emission scenario and a significant increase of 4.68% of “highly unsuitable” land, according to the RCP8.5 emission scenario compared to the baseline (1985–2005). The projected growing degree days in 2031–2050 showed a strong shortening in the growing period length compared to the baseline 1985–2006, mainly under the RCP8.5 emission scenario, with a reduction from 8% to 21% depending on crops. Moreover, crop water productivity indicated that berries were over 50% less water productive than other vegetable crops for almost the same amount of applied irrigation water. These findings highlight the vulnerability of agriculture to climate change, which requires important political and management efforts to sustain agricultural activity

Anza palaeoichnological site, Late Cretaceous, Morocco. Part III: Comparison between traditional and photogrammetric records

International audienceThe present study evaluates a methodological workflow that could identify dinosaur tracks and trackways more comprehensively at outcrop scale. The approach described here is based both on 3D modelling by photogrammetry at different resolutions, and on suitably processed digital elevation models (DEMs). The ichnosite of Anza, Morocco, was chosen to demonstrate the efficiency of the proposed pipeline, because 323 dinosaur and pterosaur tracks discovered there have already been published. One subsector containing 89 tracks, identified in the two companion works that followed a traditional approach, was selected and divided into four subzones. By combining different DEM processes (hill-shade, slope, sky-view factor, and positive openness), almost twice as many tracks (175 vs 89) are now identified in these subzones. However, the improvement is not homogeneous. In the first subzone, the previous works reported 25 tracks vs. 22 with the 3D modelling techniques used here, whereas results for the second and third subzones show considerable improvement with 3D (21 vs 38 tracks and 42 vs 81 tracks, respectively). The enhancement is even more dramatic for the fourth subzone, where 34 new tracks are now identified, whereas with the traditional approach, only one track was previously reported. It is likely that such improvements depend on several factors, i.e. the surface conditions of the rocks (e.g. irregularities, cracking, etc.), and on the preservation state and depth of the tracks. Morphometric measurements of tracks and trackways obtained from 3D models are very similar to those derived from traditional fieldwork methods. The digital approach can be applied rapidly at different resolutions, but the models acquired with the pole-mounted camera provide a good compromise, with a resolution high enough (~2 mm/pix) to spot tracks, while respecting computational constraints. Once treated, DEMs greatly facilitate the reproduction of track outlines, drawn according to criteria defined by the operator

Speleothem records decadal to multidecadal hydroclimate variations in southwestern Morocco during the last millennium

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Isotopic signatures for the assessment of snow water resources in the Moroccan high Atlas mountains: contribution to surface and groundwater recharge

International audienceTo characterize snow isotopic signatures, monitoring of snowmelt was carried out at two sites (Oukaimden and Ifni) in the Moroccan High Atlas Mountains. For the Oukaimden site, samples of snow were taken by two methods to compare sampling techniques: (1) coring with a polyvinyl chloride (PVC) tube and (2) passive capillary sampling (PCS) installed at the snow/soil interface. The analyses show variable isotope contents, ranging from −14.7 to −2.5 ‰ for oxygen-18 and from −116 to −28.2 ‰ for deuterium. The most depleted values are observed in March 2013 at high elevation (3229 m asl). The majority of snow core samples display fractionation by sublimation, whereas those collected by the PCS sampling method are close to the Global Meteoric Water Line. The isotopic signature is comparable for snow, surface water and groundwater samples, indicating that snowmelt plays an important role in recharging aquifers, lakes, and rivers on the southern and northern sides of the Atlas Mountains. Recharge by snowmelt allows the dilution of salinity in adjacent aquifers. Characterization of the stable isotopic composition of snow obtained from snow cores is limited in comparison with the PCS method, which provides realistic compositions of the melt water contribution to water resources in this semi-arid area