Mohamed Elmehdi Saidi

Cadi Ayyad University | UCAM · Department of Earth Sciences

Flood frequency analysis could be a tool to help decision-makers to size hydraulic structures. To this end, this article aims to compare two analysis methods to see how rare an extreme hydrometeorological event is, and what could be its return period. This event caused many deadly floods in southwestern Morocco. It was the result of unusual atmosph...

Precipitation is a crucial source of data in hydrological applications for water resources management. However, several regions suffer from limited data from a ground measurement network. Remotely sensed data may provide a viable alternative for these regions. This study aimed to evaluate six satellite products (GPM-F, CHIRPS, PERSIANN-CCS-CDR, GPM...

River flooding has large societal and economic impacts across Africa. Despite the importance of this topic, little is known about the main flood generating mechanisms in Africa. This study is based on 13,815 flood events that occurred between 1981 and 2018 in 529 catchments. These flood events are classified to identify the different flood drivers:...

Study region: 30 catchments in Morocco. Study focus: We assessed the KGE performance of eight monthly lumped hydrological models forced by ground-based rainfall observations. We then examined how the performance relates to model complexity and structure, applied exploratory correlation analysis to identify the catchment features (over 200 features...

Floods are posing significant threats but also play a crucial role in recharging groundwater and surface water storage in arid and semiarid regions. To improve flood knowledge in these areas, this study in South Morocco considers hourly river discharge records from 20 basins, with sparse vegetation or bare land and sandy soils, to identify over 100...

Drought assessment and management, intensified by global warming, present critical challenges in semi-arid Mediterranean regions, impacting environmental sustainability and economic stability. This study evaluates spatiotemporal drought risk in the Bouregreg watershed in northwest Morocco by integrating remote sensing data with various drought indi...

Hydrological modeling is a crucial tool for water resources management. It becomes more important in data-scarce regions like Morocco. Therefore, accurate parameter tuning of models used in this region is vital for reliable predictions. Traditionally, the Nelder-Mead Simplex Algorithm has been used to calibrate the GR4J and MISDc models. However, t...

The Mediterranean basin is recognized as a potential focal point of global warming, marked by a rising incidence of both droughts and foods. Nevertheless, uncertainties persist regarding the precise impact of climate change on the water cycle in this region. Therefore, this study endeavors to scrutinize the recent precipitation trends and fuctuatio...

This study aims to assess the accuracy of three satellite-derived products (IMERG-F, CHIRPS and PER-SIANN CDR) in quantifying the erosivity of rainfall. A network of 14 gauge stations is utilized to estimate the R-factor in west-central Morocco between 2001 and 2020. This evaluation is conducted at the basin, and the pixel scale is based on Bve sta...

The Maghreb countries located in North Africa are strongly impacted by floods, causing extended damage and numerous deaths. Until now, the lack of accessibility of river discharge data prevented regional studies on potential changes in flood hazards or the development of regional flood frequency estimation methods. A new database of daily river dis...

In data-sparse regions and in developing countries such as Morocco, where flooding has serious socio-economic impacts, satellite-based precipitation products open new possibilities for monitoring and modelling water resources and floods. The objective of the study is to explore the possibility of using satellite precipitation products (SPPs) with h...

Morocco is characterized by a semi-arid climate influenced by the Mediterranean, Atlantic, and Saharan environments, resulting in high variability in rainfall and hydrological conditions. Certain regions suffer from insufficient understanding concerning the spatiotemporal patterns of precipitation, along with facing recurrent periods of drought. Th...

Accurate and spatially distributed precipitation data are fundamental to effective water resource management. In Morocco, as in other arid and semi-arid regions, precipitation exhibits significant spatial and temporal variability. Indeed, there is an intra-and inter-annual variability and the northwest is rainier than the rest of the country. In th...

Satellite-based precipitation products, with simultaneously high spatial and temporal resolutions, are mostly needed to assess climate change repercussions. Previous research used datasets neglecting either good temporal or good spatial resolution, PERSIANN-CCSCDR, ERA5, and SM2RAIN-ASCAT are some of the projects aiming to remedy these limitations....

In most African countries, the lack of observed rainfall data is a major obstacle for efficient water resources management. The objective of this study is to evaluate satellite rainfall products’ ability to estimate river runoff over 12 basins in Morocco using four hydrological models: IHACRES, MISDc, GR4J, and CREST. Satellite products available w...

North Africa is characterized by several ungauged basins, especially in Morrocco, where satellite products could be an alternative of the lack ground-based measurements. In this study, the Land Parameter Retrieval Model (LPRM) soil moisture and the Integrated Multi-Satellite Retrievals for Global Precipitation Measurement (GPM-IMERG) were used in f...

Watershed planning is often based on the analysis of morphometric parameters, especially in poorly gauged or ungauged basins. These physiographic parameters have, in fact, a main role in water runoff. In many arid countries such as Morocco, there is a significant need for morphometric studies of watersheds to initiate integrated water resources man...

Maghreb countries are strongly impacted by floods, causing twice as many deaths as in southern European countries in recent decades. However, due to the lack of data accessibility, there are no studies to analyze whether the frequency or intensity of floods are changing at the regional scale. In this work, a recent database of daily river discharge...

Maghreb countries are strongly impacted by floods, causing twice as many deaths as in southern European countries in recent decades. However, due to the lack of data accessibility, there are no studies to analyze whether the frequency or intensity of floods are changing at the regional scale. In this work, a recent database of daily river discharge...

Ensuring water availability for agriculture and drinking water supply in semi-arid mountainous regions requires control of factors influencing groundwater availability. In most cases, the population draws its water needs from the alluvial aquifers close to villages that are already limited and influenced by current climatic change. In addition, the...

Due to the lack of observed data, climate change impact studies are difficult to conduct. This paper evaluates the effect of climate change on water resources, in a Moroccan basin, using the Final Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (GPM-IMERG-F) for precipitation and the European Reanalysis fifth generation (...

Satellite-based and Reanalysis rainfall products could be a valuable source of data for precipitation for hydrological modeling over data-scarce regions. The objective of this study is to assess the suitability of ERA5 Reanalysis and GPM IMERG V06 data (GPM-Early, GPM-Late and GPM-Final) for flood modeling over a Moroccan semi-arid watershed (Rhera...

This research aims at establishing an integrated modelling framework to assess the impact of climate change on water supply and demand across an arid area in the western Haouz plain in Morocco. Five general circulation models (GCMs) are used to evaluate the availability of future water resources under Representative Concentration Pathways (RCP4.5 a...

The Integrated Multi-Satellite Retrievals for Global Precipitation Measurement (GPM-IMERG) could be an alternative solution to the data lack problem. In this regard, this work examines the ability of this satellite-based rainfall products to simulate the flow in a Moroccan ungauged basin (Bourrous) by using the Soil Conservation Service–Curve Numbe...

The Hydrological modelling in a semi-arid mountainous area is very challenging due to the irregular climate and the spatial variability of vegetation cover and topography. The hydrological model CEQUEAU was used with a daily time step on the arid and semi-arid mountainous region of the Ourika watershed. The capability of the model to simulate the d...

In this study, we apply statistical approaches based on frequency analysis and Artificial Neural Networks to map the 100-year monthly precipitation in a Moroccan watershed. This was accomplished by using assessed and corrected satellite-based rainfall products. A network of 10 rain gauges and six statistical validation criteria was used to compare...

In Morocco, the dynamics of change in rainfall patterns have been underway for decades. It is characterized by increasingly frequent and violent hydrological and climatic events (floods and droughts). This work aims to study the peculiarities and mechanisms of the appearance of floods in the watershed of the Oudodou wadi (Province of Tiznit - south...

One of the major challenges of integrated water resources management is the lack of rainfall data in some regions. Satellite precipitation products could be an effective solution for the lack of data. In response to this challenge, this study evaluates the use of Integrated Multi-Satellite Retrievals for Global Precipitation Measurement (IMERG-GPM)...

Here, we investigate the precipitation regionalization and the spatial variability of rainfall extremes, using a 47-year long station-based dataset from western central Morocco, a region with marked topographic and climatic variations. The principal component analysis revealed three homogeneous rainfall regimes, consistent with topographic features...

Extreme climate events often have a significant and direct impact on social, economic, and environmental systems. This study is an attempt to characterize the current trends and future projections of extreme climatic indices in an arid region of Morocco on both an annual and a seasonal scale using 12 precipitation and temperature-based indices. The...

During the last few decades, the frequency of drought has significantly increased in Morocco especially for arid and semi-arid regions, leading to a rising of several environmental and economic issues. In this work, we analyse the spatial and temporal relationship between vegetation activity and drought severity at different moments of the year, ac...

The Mediterranean region is characterized by intense rainfall events giving rise to devastating floods. In Maghreb countries such as Morocco, there is a strong need for forecasting systems to reduce the impacts of floods. The development of such a system in the case of ungauged catchments is complicated, but remote-sensing products could overcome t...

A new precipitation dataset is provided since 2014 by the Global Precipitation Measurement (GPM) satellite constellation measurements combined in the Integrated Multi-satellite Retrievals for GPM (IMERG) algorithm. This recent GPM-IMERG dataset provides potentially useful precipitation data for regions with a low density of rain gauges. The main ob...

يعد حوض أوريكا -بالأطلس الكبير الغربي- من بين الأحواض المغربية الأكثر عرضة للمخاطر الهيدرولوجية وخاصة خطر الفيضانات الذي يهدد الساكنة بين الفينة والأخرى. هذا في وقت يزخر فيه هذا الحوض بموارد طبيعية غنية، أبرزها المياه، والتربة، والغطاء النباتي. وهذا ما دفع بالمتدخلين في هذا المجال الجغرافي إلى عقلنة تدبير هذه الموارد، وإدراجها ضمن سياسة الدولة، اعت...

The Mediterranean region is characterized by intense rainfall events giving rise to devastating floods. In Maghreb countries such as Morocco, there is a strong need for forecasting systems to reduce the impacts of floods. The development of such a system in the case of ungauged catchments is complicated but remote sensing products could overcome th...

Flash floods are common in small Mediterranean watersheds and the alerts provided by real-time monitoring systems provide too short anticipation times to warn the population. In this context, there is a strong need to develop flood forecasting systems in particular for developing countries such as Morocco where floods have severe socioeconomic impa...

The High Atlas of Morocco is a semi-arid mountainous environment that frequently suffers from natural hazards. For example, the watersheds upstream of Marrakech city are subject to extreme floods, caused by heavy rains. These episodes are frequent and often devastating, as was the August 1995 event that caused hundreds of deaths in the Ourika Valle...

Purpose The purpose of this paper is to identify vulnerable areas for flood hazard and to analyze stakes exposed in touristic valley of Morrocan mountains. The three goals are: methodological (low-cost diagnosis without starting data), operational (to show the risk and identify avenues of prevention in Ourika) and incentive (to reproduce this on ot...

Arid and semi-arid regions are often subject to flash floods. One of the most important tools for assessing flood intensity is the modeling of rain events. In the Tensift watershed, the frequency of past floods and their future predictions require a critical consideration of flood risk. In fact, the frequency of floods is increasing because of clim...

RESUME Avec un caractère aride à semi-aride, le climat de la région de Marrakech-Safi est assujetti à des influences océaniques et continentales. Les villes d'Essaouira et de Marrakech, qui illustrent ces deux influences, enregistrent une grande variabilité temporelle des précipitations et des températures. Par ailleurs, des tendances nettes à l'au...

In the Mediterranean region, floods are causing extended damages to the population and infrastructures. In Morocco, only a few studies have been conducted to understand flood processes while the vulnerability to floods is high. The goals of this study are to compare two modeling approaches for floods using either lumped or spatial rainfall and also...

RSHS’18 is a meeting point for researchers from both the hydrology and remote sensing communities, and brings together their joint experiene in Earth Observation for developing innovative and environmentally-sustanaible water resources and basin management. It is focused on the use of the new generation of remote sensors and applications to hydrolo...

La modélisation a une place centrale dans l’hydrologie moderne. Les modèles pluie-débit ont, à de nombreuses reprises, prouvé leur efficacité. En effet, la simulation des débits est indispensable à de nombreux secteurs économiques et pour la sécurité civile. L’objectif de ce travail est d’essayer d’étudier la zone d’Amizmiz en appliquant deux modèl...

In the last few decades, drought has become a chronic phenomenon in Morocco. It began at the end of the 1970s and continued to the late 2000s. In the present study, hydrometeorological data sets, Standardized Precipitation Index method, and non-parametric tests were used to recognize the frequency and the severity of drought events during the perio...

In the last few decades, drought has become a chronic phenomenon in Morocco. It began at the end of the 1970s and continued to the late 2000s. In the present study, hydrometeorological data sets, Standardized Precipitation Index method, and non-parametric tests were used to recognize the frequency and the severity of drought events during the perio...

In spite of its geographical situation on the Atlantic and Mediterranean coast, Morocco is one of the most arid areas of the world; it experiences highly variable rainfall and recurrent droughts. Predictions of climate change consequences on several socio-economical fields in Morocco are very alarming. In fact, climate trends observed in Marrakech...

La zone d’étude, qui s’étend sur une superficie de 5193 Km2, se situe à cheval entre les provinces d’El Haouz et de Chichaoua à une quarantaine de kilomètres de la ville de Marrakech. Ce secteur est composé de trois zones topographiques distinctes : une zone de montagnes du Haut Atlas, une zone de piémont et une zone de plaine. Les deux principaux...

Within the context of climate change and increasing demographic pressures, problems of water resources variability have become particularly crucial. The management of arid watersheds, which are highly exposed to droughts and floods, needs to be supported by a thorough understanding of their susceptibility to these hazards. The watershed of Tensift...

Obviously, floods have natural causes – heavy rainfall in the case of flash floods – nevertheless, their consequences depend strongly on urbanization and land use. On both sides of the Mediterranean, regions have been subjected to fast changes which have led to a concentration of assets in valleys and coastal areas (Plan Bleu, 2008). Changes in lan...

1. Résumé : Ce travail se propose de contribuer à l'étude d'un milieu montagnard semi aride : le bassin versant de l'Oued R'Dat. L'oued principal prend source des hauts sommets de l'Atlas hercynien et trace sa trajectoire tout au long de paysages post-hercyniens jusqu'à l'exutoire de Sidi Rahal. C'est un milieu marqué par une grande diversité morph...

Apport des logiciels de SIG dans la morphométrie des bassins versants L'exemple d'ArcGIS. Guide méthodologique d'utilisation. Mohamed El Mehdi SAIDI, Décembre 2013. Université Cadi A yyad Marrakech.

This work is devoted to the simulation and spacialisation of natural flows at the Ourika Valley in Morocco. Subject to climatic and anthropogenic forcing, the valley's flood flows are, nowadays, extremely high compared to the average flow. Decadal and centennial floods simulation was undertaken using two software solutions. The floodplains mapping...

Morocco, due to its location in the Mediterranean circumference, is vulnerable to present and future climate variability and climate change. Its surface water resources are becoming ever more limited and difficult to exploit. It might be expected that the warming of the hot season and drought would result in an increase in arid and semi-arid regime...

The wadi Issil originates in the High Atlas of Marrakesh, at altitudes above 2000 m. The mountainous part of the watershed is characterized by significant slopes, a low-permeable bedrock and a widespread dense hydrographic network.Concerning precipitation, the upstream stations of the basin record heavy and high rainfall levels. The average value e...

Le bassin versant du Ksob à Adamna est un hydrosystème du Haut-Atlas occidental de 1483 km² de superficie. Les précipitations sont, dans l’ensemble, conformes au milieu semi aride avec des hauteurs moyennes annuelles de 305 mm. A l’exutoire, l’écoulement superficiel est en moyenne de l’ordre de 24 mm par an (1,13 m3/s). Cependant les crues de l’oue...

Le Haut Atlas de Marrakech est une zone géographique composée des bassins versants du N’Fis, de la Gheraya, de l’Ourika, du Zat et du Ghdat. Ces bassins versants sont situés sur le flanc nord de la haine montagneuse du Haut Atlas. Ils sont donc exposés aux flux perturbés océaniques en provenance du Nord et du Nord Ouest. Ces flux arpentent les vers...

The watershed of the Ourika River is a part of the Marrakech hydrosystem of the High Atlas. In the montaneous part of the watershed, the bedrock has a low permeability, the vegetation is sparse on steep slopes and rare on the upper areas, the main valleys are narrow and deep. The N to NW exposure favours rain falls which are usually strong, short i...

The watershed of the Ourika River is a part of the Marrakech hydrosystem of the High Atlas. In the montaneous part of the watershed, the bedrock has a low permeability, the vegetation is sparse on steep slopes and rare on the upper areas, the main valleys are narrow and deep. The N to NW exposure favours rain falls which are usually strong, short i...

Situada en una zona semi-árida, en el extremo occidental del Alto Atlas, la cuenca vertiente del Ksob presenta una forma alargada con pendientes bastante importantes en las cuencas afluentes y sus vertientes. La mayoría de los afloramientos son bastante impermeables, compuestos principalmente por rocas carbonatadas jurásicas y cretácicas. Estas car...