Ali Rhoujjati

Faculté des Sciences et Techniques Marrakech · Sciences de la terre

Study region: The Atlas Mountains of Morocco, specifically the High Oum Er-rbiaa (HOER) and Ourika catchments. Study focus: to identify the recharge processes within the semi-arid watersheds, in the Atlas Mountains, through monthly monitoring of snow, rainfall, surface water, and groundwater isotope signal, but also the usage of remote sensing data...

Morocco, being part of the Mediterranean basin, is characterized by a semi-arid climate heavily affected by climate change, spatial heterogeneity of the water resources along with its high demand. As the region heavily relies on precipitation to supply surface and groundwater, the restraints are a capital threat to its availability. Therefore, cond...

The Zeïda mining center, closed in the mid-1980s, was once intensively exploited for lead concentrates. Throughout its activity, more than 12 Mt of tailings were generated and, to this day, they are still abandoned in the open air, exposed to weathering conditions without any rehabilitation. The purpose of the present study is to evaluate the envir...

Understanding mountain climates poses many challenges, because difficult terrain leads to a sparsity of weather stations and therefore poor data availability, meaning the detailed information required to understand these complex systems is lacking. Here, we analyze eleven years of half-hourly climate observations from the Joint International Labora...

The High Oum-Er-Rbia basin, located in the Moroccan Middle Atlas, is a karstic region with significant water sources that have essential functions regarding agriculture, hydropower production, industrial and drinking water. The region contains abundant wetlands, especially springs, rivers and natural lakes. These systems are highly sensitive to the...

The concentration level of a certain metal in soil is often the guideline for evaluating its contamination level. In such a process, ecological standards are the guidelines for assessing ecological risks. In the presence of certain conditions, the risk of contamination can expand beyond the concerned area creating a threat that is based on mobility...

Assessing biodiversity loss and species extinction is necessary to warn society and raise awareness of the impacts of ongoing climate change. Prioritizing protected areas is the pragmatic and applicable management measure under the pressure of ongoing climate change and limited resources to conserve species at risk of extinction. We developed a nov...

Significance Explaining the greening of the Sahara during the Holocene has been a challenge for decades. A strengthening of the African monsoon caused by increased summer insolation is usually cited to explain why the Sahara was vegetated from 14,000 to 5,000 y ago. Here, we provide a unique climate record of quantified winter, spring, and summer p...

The study assesses the levels of 16 heavy metals (HMs) in soils around the Zeïda mine to provide information on the extent of contamination, the ecological risk of these HMs in soils, and the health risk to the residents of the Zeïda village. Total metal concentrations were determined by inductively coupled plasma-mass spectrometry (ICP-MS) for 20...

The perennial and seasonal wetland diversity of the Moroccan Middle Atlas region provides a valuable “test-bed” for understanding the response of different hydrosystems to climatic variations. A multiproxy study, based on sedimentological descriptions, together with mineralogy, carbonate content, XRF core scanning and biological proxies supported b...

Metal Mining Contamination is a widespread problem in the world. However, the assessment of abandoned mine metal contamination, especially in Morocco, has not been studied sufficiently. In this study, a total of 83 samples of water, sediments, and soils were collected to investigate the concentrations of heavy metals (HMs) around an abandoned minin...

There are no glaciers today in the High Atlas, Morocco. However, there is evidence that niche glaciers and late-lying snowpatches in the High Atlas were present as recently as the last century and there are at least four sites where snowpatches appear to survive some summer seasons today. Many other sites also support non-perennial late-lying snow...

As many Mediterranean headwater catchments, the Moroccan Middle Atlas plays an important role in the highly vulnerable regional water resources. Mountain lakes are numerous in this region, and could be regarded as possible sentinels of hydro-climatic changes, using appropriate modelling tools able to simulate the lake-climate relation. We present a...

The origin of modern disjunct plant distributions in the Brazilian Highlands with strong floristic affinities to distant montane rainforests of isolated mountaintops in the northeast and northern Amazonia and the Guyana Shield remains unknown. We tested the hypothesis that these unexplained biogeographical patterns reflect former ecosystem rearrang...

The origin of modern disjunct plant distributions in the Brazilian Highlands with strong floristic affinities to distant montane rainforests of isolated mountaintops in the northeast and northern Amazonia and the Guyana Shield remains unknown. We tested the hypothesis that these unexplained biogeographical patterns reflect former ecosystem rearrang...

This study concerns the Takerkoust dam, located at the outlet side of N'fis watershed (Western High Atlas, Morocco). It is one of the main strategic reservoirs in Morocco. Built in 1935, it experiences a serious problem of siltation due to soil erosion. In order to reduce the risk of erosion, a new dam was implanted upstream, at Ouirgane in 2008. A...

The aim of this work is to reconstruct the periods of growth and decline of human populations in Morocco and their potential impacts on the landscape over the past 10,000 years. In order to estimate the trends in the human population size between 10,000 and 3000 years ago, we used a summed probability distribution (SPD) of radiocarbon dates from a...

Study of the hydro-sedimentary dynamics of lakes provides key information on hydrological changes. In this work, we investigate Lake Azigza in the Moroccan Middle Atlas, a region that suffers from a scarcity of observational hydrological data necessary for a coherent management of water resources. Sedimentary deposits of Lake Azigza (32°58′N, 5°26′...

This study discussed the environmental fate and ecological hazards of heavy metals in the soil-plant system and sediment-water column around the former Pb-Zn mining Zeïda district, in Northeastern Morocco. Spatial distribution, pollution indices, and cluster analysis were applied for assessing Pb, Zn, As, Cu and Cd pollution levels and risks. The g...

This study reconstructs and interprets the changing range of Atlas cedar in northern Morocco over the last 9,000 years. A synthesis of fossil pollen records indicated that Atlas cedars occupied a wider range at lower elevations during the mid-Holocene than today. The mid-Holocene geographical expansion reflected low winter temperatures and higher w...

In northern Middle Atlas, the Dayet Iffere is located in an area affected by karst and tectonic. After its watershed genesis of middle altitude during the upper Pleistocene, two lacustrine formation were deposed. The detailed sedmentological study as well as the correlations between the different lacustrine formations defined in Dayet Afourgagh and...

The aim of this study is to reconstruct the impact of past environmental changes in the Moroccan Rif mountainous ecosystems. We collected an 8.5 m sedimentary core in the western part of the Rif and analyzed its palynological content, micro-remains of fossil charcoal, particle size, and content of several chemical elements. The chronology of the re...

The present study aims at reconstructing past climate changes and their environmental impacts on plant ecosystems during the last 6000 years in the Middle Atlas, Morocco. Mean January temperature (Tjan), annual precipitation (Pann), winter (Pw) and summer (Ps) precipitation, and a seasonal index (SI) have all been quantified from a fossil pollen re...

A new fossil record from the southern Middle Atlas spans continuously the last 25 000 years and provides evidence of an increased amount of snow precipitation during the last glacial period and a warm early Holocene with rather dry climate conditions. This environmental reconstruction is based on a multi-proxy approach that integrates pollen, micro...

Depuis les années 1990, le bassin méditerranéen subit une augmentation des événements de précipitation et de sécheresse extrêmes susceptibles de s’amplifier au cours du XXIe siècle, et dont l’origine est attribuable aux activités anthropiques depuis la révolution industrielle de 1850 (IPCC, 2013). Les résultats issus des modèles climatiques régiona...

The Holocene climate is known to be rather stable although with few abrupt changes that lasted few decades. The present study is related the climate changes and their environmental impacts during the last 6000 years from a fossil record collected in the Middle Atlas, Morocco. Reconstruction of three climate variables (January temperature (Tjan), an...

The present study aims to review palaeoecological evidence for environmental changes induced by human activities over the last few millennia in the montane landscapes of Morocco. The study is based on well-dated pollen and geochemical records from the Rif and the Middle Atlas mountains, to show spatial and temporal variation in the onset and intens...

Natural environmental changes may be reconstructed by studying lake sediments that record several climatic, hydrologic and environmental signatures. Such reconstructions must be based on a thorough knowledge of the current lake system conditions. According to this perspective, two karstic lakes in the Moroccan Middle Atlas, Aguelmam Azigza (32°58'N...

Stable isotopes of water (18 O, 2 H) and their associated isotope fractionation during water-cycle phase changes produce a natural labelling of the water cycle and can be efficiently use to study hydrological and climatic processes at the local, regional and global scales. Moreover, understanding the seasonal and inter-annual stable isotope behavio...

A new record from the heart of the Moroccan Middle Atlas cedar forests spans the last 18 000 years and provides valuable insight into our understanding of the natural vegetation and environmental changes. The approach is based on the study of pollen content, geochemical elements and grain size analysis. The pollen data indicate that the vegetation...

The scenic lakes Tislit and Isli of the Imilchil area in the central High Atlas of Morocco have been recently promoted to the rank of “dual impact crater” by a group of geoscientists. This was promptly denied by a group of meteorite specialists, but the first team reiterated their impact crater interpretation, now restricted to Lake Isli. This alle...

This study assesses the metal contamination of soils in the vicinities of Aouli, Mibladen and Zeida mines abandoned in the High Moulouya in eastern Morocco focusing in particular on its spatial variability as well as on the extent of the contaminated area. The results show that the studied soils close to mining sites and even very remote are highly...

Paleofire activity in North Africa and its connections with past climatic changes still remains poorly documented. A new multiproxy analysis using mineralogy, geochemistry and microcharcoal data from Lake Ifrah (Middle Atlas, Morocco) provides new insights for better understanding paleofire occurrence from the Last Glacial Maximum to the present. T...

Moroccan middle Atlas is a climatically sensitive area to the influence of Mediterranean sea, Saharan desert and Atlantic ocean air masses. It encloses several natural small lakes preserved from anthropogenic perturbations. A ten-meter-long core from Iffer lake provided a record of palaeoclimatic and paleohydrologic conditions in the Middle Atlas d...

Moroccan middle Atlas is a climatically sensitive area to the influence of Mediterranean sea, Saharan desert and Atlantic ocean air masses. It encloses several natural small lakes preserved from anthropogenic perturbations. A ten-meter-long core from Iffer lake provided a record of palaeoclimatic and paleohydrologic conditions in the Middle Atlas d...

A borehole core from Lake Ifrah (Middle Atlas, Morocco) provided a unique, continuous record of environmental change spanning the past c. 29,000 years cal BP (29 ka). A study of its organic matter, carbonates and magnetic susceptibility allowed us to reconstruct past climate changes and their impact on the lake's catchment area.The geochemical and...