Oum Er Rbia River Research Articles

Implementation of a Temperature Monitoring and Measurement Network in the Urban Context: A Case Study of Kasba Tadla, Morocco, 2022.

Abstract In the context of climate change, this study focuses on the impact of heatwaves, which have become the dominant meteorological phenomenon in terms of duration and intensity. The objective is to understand the temporal variation of temperatures in the urban domain, highlighting thermal differences on an hourly scale. The city of Kasba Tadla, located in the Tadla plain in Morocco, is at the core of this research. This rapidly expanding urban area is traversed by the Oum Er-rbia River. The selection of this region allows for a specific analysis of the climate challenges a rapidly growing city may face. The methodology relies on a network of four fixed meteorological stations installed in the city of Kasba Tadla. Temperature measurements were taken on an hourly timescale during the summer of 2022. This approach enables a detailed analysis of temperature variation based on building density and the presence of vegetation in different neighborhoods. The results highlight a significant temperature variation within the city, emphasizing the impact of building density and vegetation on this phenomenon.

Ecohydraulics-based environmental flow assessment in two arid North African rivers

North Africa is among the most water-stressed regions in the world; still, the habitat requirements of its freshwater biota are largely unknown. In this study, (i) we developed habitat suitability curves (HSCs) for freshwater macroinvertebrates in two poorly studied, regulated North African rivers (Ziz and Oum Er-Rbia), and (ii) assessed environmental flows downstream of each river dam by incorporating the HSCs in two-dimensional ecohydraulic models. We demonstrate a low-cost sampling methodology combined with freely distributed ecohydraulic modeling software. The results showed that macroinvertebrates in the arid-desert Ziz River could tolerate a wide range of habitats in terms of flow velocity and water depth compared to the arid-steppe Oum Er-Rbia River, probably due to their adaptation to extreme (arid-desert) environmental conditions. Optimal environmental flows downstream of the Al Hassan Addakhil (Ziz River) and the Al Massira (Oum Er-Rbia River) dams were 1 m3/s and 2 m3/s, respectively. However, environmental flows at 0.5 m3/s and 1 m3/s, respectively, could still maintain sustainable freshwater biota downstream of the dams. The results further highlight the critical status of the Ziz River, which was completely dry, and the alarming status of the Oum Er-Rbia River due to the significant reduction in the water levels of the Al Massira Dam. In a continuously changing climate, we suggest that the proposed environmental flows should be immediately delivered to prevent droughts and ensure healthy freshwater communities downstream of the dams, within a basin-wide freshwater management framework. In this water scarce region, more research is necessary to increase ecological awareness about these understudied freshwater systems and achieve a balance between human needs and ecosystem requirements.

Investigation of the Water Quality in Oum Er Rbia River (Morocco): A Multifaceted Analysis of Physicochemical, Undesirable Substances, Toxic Compounds, and Bacteriological Traits

Investigation of the Water Quality in Oum Er Rbia River (Morocco): A Multifaceted Analysis of Physicochemical, Undesirable Substances, Toxic Compounds, and Bacteriological Traits

Water treatment: Aluminum sulfate, polymer, and activated carbon between efficacy and overdosing. Case of Oum Er-Rbia River, Morocco

This article examines the impact of aluminum sulfate, polymer, and activated carbon on water treatment processes. General observations indicate that aluminum sulfate effectively reduces turbidity, but excessive use can result in reagent wastage. Similarly, polymer addition reduces turbidity up to an optimal dosage, beyond which it may contribute to increased turbidity and the same thing for activated carbon. The study emphasizes the significance of conducting jar tests to optimize the quantities of these chemicals through design of experiments (DOE), aiming to improve treatment effectiveness in order to meet international requirements in term of turbidity norms while reducing costs. By achieving the right balance, water treatment processes can efficiently remove suspended solids, leading to improved water clarity.

Deep Learning Approach with LSTM for Daily Streamflow Prediction in a Semi-Arid Area: A Case Study of Oum Er-Rbia River Basin, Morocco

Daily hydrological modelling is among the most challenging tasks in water resource management, particularly in terms of streamflow prediction in semi-arid areas. Various methods were applied in order to deal with this complex phenomenon, but recently data-driven models have taken a better space, given their ability to solve prediction problems in time series. In this study, we have employed the Long Short-Term Memory (LSTM) network to simulate the daily streamflow over the Ait Ouchene watershed (AIO) in the Oum Er-Rbia river basin in Morocco, based on a temporal sequence of in situ and remotely sensed hydroclimatic data ranging from 2001 to 2010. The analysis adopted in this work is based on three-dimension input required by the LSTM model (1); the input samples used three splitting approaches: 70% of the dataset as training, splitting the data considering the hydrological year and the cross-validation method; (2) the sequence length; (3) and the input features using two different scenarios. The prediction results demonstrate that the LSTM performs poorly using the default data input scenario, whereas the best results during the testing were found in a sequence length of 30 days using approach 3 (R2 = 0.58). In addition, the LSTM fed with the lagged data input scenario using the Forward Feature Selection (FFS) method provides high performance accuracy using approach 2 (R2 = 0.84) in a sequence length of 20 days. Eventually, in applications related to water resources management where data are limited, the use of the deep learning technique is able to create high predictive accuracy, which can be enhanced with the right combination subset of features by using FFS.

Modeling the Hydrological Impacts of Vegetation Cover Changes in the Upper Oum Er-Rbia Watershed (Morocco)

In Morocco, the mountainous areas are often exposed to bulky and vicious flows of water and sediment. This process is exacerbated by the decrease in vegetation cover and the disruption in rainfall-runoff conditions that frequently cause significant flooding. By exploring the main hydrologic elements of these processes, it is possible to understand the behavior and hydrological response of watersheds and thus plan accordingly. In this study, the authors focused on determining the morphometric characteristics of the upper Oum Er-Rbia River basin (UOERRB by assessing/ evaluating the land use and land cover changes for a period of 32 years (1984–2016). Hydrologic Engineering Center’s Hydrologic Modeling System (HEC-HMS) was applied to simulate four daily hydrological events. The concentration time was 7.7 hours. The four storm events examined to calibrate and validate the simulated outflow at the outlet indicated a good agreement between the hydrographs of the measured and simulated flows, with an average Nash-Sutcliffe efficiency (NSE) value ranging from 0.63 to 0.76. Between 2002 and 2016, an average 6.21 percent increase in vegetation cover of with annual rainfall increasing from 690 to 714.1 mm/year was observed. These results can contribute to a better understanding of the hydrologic processes and better estimation of the return flows and thus guiding management decisions and developments in the UOERRB.

Geotechnical studies for Landslide susceptibility in the high basin of the Oum Er Rbia river (Morocco)

ABSTRACT In the high basin of Oum Er Rbia in the Middle Atlas Mountain, the steep slopes with inherent soil lead to the formation of landslides, which could pose danger to road infrastructure and buildings. Evenly the heavy rains exceeding the saturation of soils play a key role in landslides. In this context, this study attempted to assess unconsolidated soil characteristics and their impacts on landslide susceptibility. The texture, clay mineralogy, and Atterberg limits were determined for soil samples. Atterberg limits were conducted to estimate the swell potential of the soil and eventually classify the soil samples as swelling or non-swelling. As a result of the geotechnical studies, the average of the liquid limit values was between 28% and 56%, and the mean plasticity index of the units ranged from 13% to 24% in the overlying materials in the landslide zones. XRD analysis revealed that the most dominant mineral identified was quartz; illite minerals.

Effect of the self-purification of Oum Er Rbia river on the elimination of fish releases

Fish farming is a rapidly growing production worldwide, where it covers nearly 50% of fish inputs for human consumption. Releases to the natural environment are also an important issue, especially as they are visible and quantifiable, being emitted directly into the water.The physicochemical analyzes of the various Oued Er-Rbia points (ES, P1, P2, P3 and E4) show that the physico-chemical quality of the water downstream of the OumEr-Rbia magnification station shows no signs of deterioration of the receiving releases.Fish farming effluents are known to deteriorate the quality of freshwater and the excessive presence of nitrogen and phosphorus in the water leads to eutrophication of the environment. This is not the case at the Oum Er-Rbia station, but it is crucial to develop food formulations that cause the least amount of nitrogen and phosphorus released into the environment.

Analysis of precipitation time series and regional drought assessment based on the standardized precipitation index in the Oum Er-Rbia basin (Morocco)

The Oum Er-Rbia river basin, located in the Midwest of Morocco, is one of the largest watersheds in the country. Owing to its strategic importance, it has attracted important investments in hydraulic infrastructures. However, the variability of the meteorological and hydrological regimes leads to water scarcity in this region. Therefore, it is essential to analyze drought characteristics at the river basin scale. This study intends to analyze a large data set obtained from 25 weather stations during a period of 42 years (1970–2011) and to estimate the regional drought characteristics. We have analyzed precipitation data by linear regression and vector methods to develop a complete and homogeneous rainfall database. Next, we have estimated the drought characteristics, frequency, and duration, using the standardized precipitation index. Results indicate the occurrence of dry periods during the following time intervals 1980–1987, 1991–1995, 1997–2002, and 2006–2008 in the Oum Er-Rbia river basin. They exhibit a relatively high frequency with intensity ranging between moderate and severe. The spatial extent of droughts in the basin has increased over time. This could have impacts on water resource availability.

GIS-multicriteria evaluation using AHP for landslide susceptibility mapping in Oum Er Rbia high basin (Morocco)

BackgroundHigh basin of Oum Er Rbia River, which is located in Middle Atlas Mountain region, is prone to landslide problems due to the geological features combined with the climate change and human activities. The present work including inventory mapping was conducted to establish landslide susceptibility map using GIS-based spatial multicriteria approach. Eight landslide-related factors, including land cover, lithology, distance to road, distance to fault, distance to drainage network, elevation, aspect and slope gradient, were selected for the present assessment. Weight for each factor is assigned using Analytic Hierarchy Process (AHP) depending on its influence on the landslide occurrence. The landslide susceptibility map was derived using weighted overlay method and categorized into five susceptible classes namely, very low (VL), low (L), moderate (M), high (H).ResultThe results revealed that 30.16% of the study area is at very low risk, 12.66% at low risk, 25.75% of moderate risk, 22.59% of high risk and 9.11% of very high risk area coverage. The very high landslide vulnerability zones are more common within the river valleys on steep side slopes. Most landslides also involve rocks belonging to the Triassic weathered marl and clay-rich formation. Moreover, human activities namely the construction and the expansion of agricultural lands into forests intervene in inducing landslides through altering the slope stability along the river banks. Lastly, effectiveness of these results was checked by computing the area under ROC curve (AUC) that showed a satisfactory result of 76.7%.ConclusionsThe landslide susceptibility map of the Oum Er Rbia high basin provides valuable information about present and future landslides, which makes it viable. Such map may be helpful for planners and decision makers for land-use planning and slope management.

Trend analysis of rainfall and drought over the Oum Er-Rbia River Basin in Morocco during 1970–2010

In a context of water scarcity in Morocco, the proper management of water resources is becoming a national priority. However, the strong spatiotemporal fluctuation of rainfall, considered as the first source of surface water intakes, complicates attempts to work on such a long-term purpose. In this work, we aim to provide an analysis of rainfall variability over the Oum Er-Rbia (OER) River basin, one of the most important basins in Morocco. For this, we assessed the annual rainfall deficit using the Standardized Precipitation Index (SPI) and then analyzed trends at annual, seasonal, and monthly bases using the Mann–Kendall test. The study was conducted on a set of data from 15 stations over a 40-years period (1970–2010). The results show that the OER River basin tends towards drier conditions. An abundance of deficit seasons has been noticed (50 to 63% of the seasons), especially after 1980–1981. Since then, the basin has known several deficit periods, sometimes of great spatial extent such as those that occurred in the 1980s and 1990s. Moreover, during the study period, the total annual rainfall has demonstrated a general decreasing tendency. The latter was mainly induced by changes in winter and spring months, which experienced some of the largest decline rates with a special abundant significance during the month of April.

Remote sensing and GIS techniques for prediction of land use land cover change effects on soil erosion in the high basin of the Oum Er Rbia River (Morocco)

Soil erosion by water is one of the most important causes of land degradation throughout the world, particularly in arid and semi-arid areas. The high basin of the Oum Er Rbia River, located in the Middle Atlas (Morocco), is a mountainous area dominated by steep slopes and clayey soils, which make it vulnerable to soil erosion due to human activities and severe weather. Multidate satellite images of Sentinel 2A, Landsat Oli-8 and ETM acquired respectively in 2017, 2013 and 2003, and the Cellular Automata Markov (CA_Markov) model were used to forecast the land use/land cover map and their change detections. The Revised Universal Soil Loss Equation (RUSLE) was integrated in a GIS environment to quantify soil loss and to map erosion risk of the specific years.The estimated annual soil losses average was 58 t ha−1 yr−1 in 2003, and the predicted annual soil loss average for 2030 was 142 60 t ha−1 yr−1. The results demonstrate that using CA_Marcov and RUSLE in combination with remote sensing and GIS is a suitable method for forecasting LUCC and accurately measuring the quantity of soil losses in the future.

A TOPSIS approach-based morphometric analysis for sub-watersheds prioritization of high Oum Er-Rbia basin, Morocco

The study area covers 1871 km2 is located in the upstream of Oum Er-Rbia river basin, between latitudes 33° and 34° North, and longitudes 4°30′ and 5°20′ East. Watersheds prioritization based on morphometric parameters through the analysis of linear, areal and relief aspects is necessary in order to develop a sustainable watersheds management plan. The High Oum Er-Rbia basin has been subdivided into 17 sub-watersheds using remote sensing data (Aster-DEM) and Geographic Information System. For prioritization of sub-watersheds. The Multi-Criteria Analysis through the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), were applied to determine the relative weights of various parameters. Linear parameters; such as bifurcation ratio (Rb), drainage density (Dd), stream frequency (Fs), drainage texture (Dt), and shape parameters such as form factor (Rf), shape basin (Bs), elongation ratio (Re), compactness constant (Cc), and circularity ratio (Rc). The present study is an attempt to use TOPSIS approach based morphometric indices for prioritization of watersheds for water and soil resources conservation and management. The results show that sub-watersheds 2 and 6 have been ranked 1 and 2 assigned to highest closeness (C i + ) to ideal solution with 0.6838 and 0.6788 respectively. These sub-watersheds must be given the highest priority for soil and water conservation measures, to insure future sustainable agriculture, water quality and to prevent silting of Ahmed El-Hansali Dam.

Remote sensing approach to assess salt-affected soils in the north-east part of Tadla plain, Morocco

Recently, the remote sensing technologies have been used increasingly in various domains in order to explain or detect different phenomena in a rapid manner and covering large areas. This study aims to use Landsat 8 Oli imagery product to elaborate a map of soil salinity in the north-east part of Tadla plain, by implication of spectral reflectance and electrical conductivity (EC) measured in the laboratory. Based on salinity Index (SI), the Normalized Differential Salinity Index (NDSI), and Landsat bands, we carried out a statistical study via the JMP13 software to determine the most correlated bands with EC measured. The obtained results were very satisfactory with an R2 = 71.3% and root mean square error (RMSE) of 0.084. The elaborated map showed that the salinity is high near Oum Er Rbia River and the two cities of Beni-Mellal and Ouled Yaich, which is due to saline waters of Oum Er Rbia River and Béni-Moussa-East (Dir) groundwater used for irrigation. These results signify that the combination of remote sensing and laboratory EC measurements would be a suitable method for predicting soil salinity.

Calibration of a large-scale hydrological model using satellite-based soil moisture and evapotranspiration products

Abstract. A considerable number of river basins around the world lack sufficient ground observations of hydro-meteorological data for effective water resources assessment and management. Several approaches can be developed to increase the quality and availability of data in these poorly gauged or ungauged river basins; among them, the use of Earth observations products has recently become promising. Earth observations of various environmental variables can be used potentially to increase knowledge about the hydrological processes in the basin and to improve streamflow model estimates, via assimilation or calibration. The present study aims to calibrate the large-scale hydrological model PCRaster GLOBal Water Balance (PCR-GLOBWB) using satellite-based products of evapotranspiration and soil moisture for the Moroccan Oum er Rbia River basin. Daily simulations at a spatial resolution of 5 × 5 arcmin are performed with varying parameters values for the 32-year period 1979–2010. Five different calibration scenarios are inter-compared: (i) reference scenario using the hydrological model with the standard parameterization, (ii) calibration using in situ-observed discharge time series, (iii) calibration using the Global Land Evaporation Amsterdam Model (GLEAM) actual evapotranspiration time series, (iv) calibration using ESA Climate Change Initiative (CCI) surface soil moisture time series and (v) step-wise calibration using GLEAM actual evapotranspiration and ESA CCI surface soil moisture time series. The impact on discharge estimates of precipitation in comparison with model parameters calibration is investigated using three global precipitation products, including ERA-Interim (EI), WATCH Forcing methodology applied to ERA-Interim reanalysis data (WFDEI) and Multi-Source Weighted-Ensemble Precipitation data by merging gauge, satellite and reanalysis data (MSWEP). Results show that GLEAM evapotranspiration and ESA CCI soil moisture may be used for model calibration resulting in reasonable discharge estimates (NSE values from 0.5 to 0.75), although better model performance is achieved when the model is calibrated with in situ streamflow observations. Independent calibration based on only evapotranspiration or soil moisture observations improves model predictions to a lesser extent. Precipitation input affects discharge estimates more than calibrating model parameters. The use of WFDEI precipitation leads to the lowest model performances. Apart from the in situ discharge calibration scenario, the highest discharge improvement is obtained when EI and MSWEP precipitation products are used in combination with a step-wise calibration approach based on evapotranspiration and soil moisture observations. This study opens up the possibility of using globally available Earth observations and reanalysis products of precipitation, evapotranspiration and soil moisture in large-scale hydrological models to estimate discharge at a river basin scale.

Determination for levels of uranium and thorium in water along Oum Er-Rabia river using alpha track detectors

Different river water samples have been collected and analyzed from different locations along Oum Er-Rbia River in Morocco. The uranium and thorium concentrations were investigated in the studied river and dam water samples. Mean activity concentrations of uranium and thorium in water were found to be between 12 and 37 Bq.m−3 and 2–10 Bq.m−3, respectively. The pH measured at all river water simples was slightly alkaline and ranged from 7.5 to 8.75. The electrical conductivity ranged from 2790 to 794 μS cm−1. It was found that uranium and thorium concentrations were correlated with some chemical parameters in Oum Er-Rabia River water. Uranium and thorium measurements in this river are important for monitoring environmental radioactivity and to know the geochemical behaviour of these radionuclides in the surficial water bearing environments.

Assessment of spatial and seasonal water quality variation of Oum Er Rbia River (Morocco) using multivariate statistical techniques

The aim of this study is to assess the spatial and temporal water quality variation and to determine the main contamination sources in the Oum Er Rbia River and its main tributary, El Abid River. The water quality data were collected during 2000–2012 from fourteen sampling stations distributed along the river. The water quality indicators used were TEMP, pH, EC, turbidity, TSS, DO, NH4+, NH3–, TP, BOD5, COD and F. coli. The water quality data was analyzed using multivariate statistical methods including Pearson's correlation, PCA, and CA. The results showed that in some stations the water quality parameters were over Moroccan water standards. PCA applied to compare the compositional patterns among the analyzed water samples, identified and four factors accounting for almost 63% of the total variation in the data. This suggests that the variations in water compounds’ concentration are mainly related to point source contamination (domestic and industrial wastewater), non-point source contamination (agriculture activities), as well as natural processes (weathering of soil and rock). CA showed relatively spatial and seasonal changes in surface water quality, which are usually indicators of contamination with rainfalls or other sources. Overall, this study showed that the water was potentially hazardous to health of the consumers and highlighted the need to treat industrial and municipal wastewater and to encourage sustainable agricultural practices to prevent adverse health effects. We therefore suggest wise management of anthropogenic activities in the catchment of Oum Er Bia River and their tributaries.

Pearl mussels (Margaritifera marocana) in Morocco: Conservation status of the rarest bivalve in African fresh waters

Margaritifera marocana is one of the rarest freshwater mussel species (listed as critically endangered), and is endemic to Morocco. Despite its constrained distribution and low abundance, to date there are no quantitative studies addressing the conservation status of this species. Surveys were conducted in 36 sites along the Oum Er Rbia river basin (Rivers Derna, Laabid and Oum Er Rbia) to assess the distribution, abundance, population structure and genetic diversity of M. marocana. Just one specimen was found on River Oum Er Rbia and none on River Derna; however, a high abundance was found in the lower section of River Laabid (e.g., site Laabid 6 reached a mean density of 11.0±6.8ind.m−2). Contrary to earlier information, which reported an overall population size fewer than 250 individuals in a restricted area and no juvenile presence, this study showed that a much higher abundance exists in River Laabid alone. In addition, the species is present in more than 50km of this river and is still recruiting since small specimens were found. Regarding genetic diversity, six of nine loci previously used in Margaritifera margaritifera were polymorphic and suitable in M. marocana. The spatial range contraction of this species is likely to be very recent, since no strong signature was detected by the molecular diversity indices. Information gathered in this study can be used as a reference to the present conservation status of M. marocana, and guide future research and management initiatives to better conserve it. We conclude discussing the potential major threats for the future survival of M. marocana and suggest some management measures (and research needs) that should be urgently applied.

Evaluation for Moroccan dynamically downscaled precipitation from GCM CHAM5 and its regional hydrologic response

Abstract Study region Morocco (excluding Western Sahara). Study focus This study evaluated Moroccan precipitation, dynamically downscaled (0.18-degree) from three runs of the studied GCM ECHAM5/MPI-OM, under the present-day (1971–2000/20C3M) and future (2036–2065/A1B) climate scenarios. The spatial and quantitative properties of the downscaled precipitation were evaluated by a verified, fine-resolution reference. The effectiveness of the hydrologic responses, driven by the downscaled precipitation, was further evaluated for the study region over the upstream watershed of Oum er Rbia River located in Central Morocco. New hydrological insights for the region The raw downscaling runs reasonably featured the spatial properties but quantitatively misrepresented the mean and extreme intensities of present-day precipitation. Two proposed bias correction approaches, namely stationary Quantile-Mapping (QM) and non-stationary Equidistant CDF Matching model (EDCDFm), successfully reduced the system biases existing in the raw downscaling runs. However, both raw and corrected runs projected great diversity in terms of the quantity of future precipitation. Hydrologic simulations performed by a well-calibrated Variable Infiltration Capacity model successfully reproduced the present-day streamflow. The driven flows were identified highly correlated with the effectiveness of the downscaled precipitation. The future flows were projected to be markedly diverse, mainly due to the varied precipitation projections. Two of the three flow simulation runs projected slight to severe drying scenarios, while another projected an opposite trend for the evaluated future period.

Exploitation et salinité des aquifères de la Chaouia côtière, littoral atlantique, Maroc

The coastal plain of Chaouia, located on the Atlantic shoreline of Morocco, has a semiarid climate and consists of two aquifers: schist in the northeast and carbonate in the southwest. These aquifers are affected by evaporation and by intensive pumping for irrigation and drinking water. The groundwater reserves are seriously affected and the salinity increased, especially near the ocean and in the Oum Er Rbia River. Therefore, for many wells, exploitation has ceased due to them being dried out or having high salinity. To determine the causes of the high salinity, 18O/ 16O isotopes were used to enable the identification of areas where groundwater is effected by the influence of ocean water.