14 research outputs found
Solar Desalination: Current Applications and Future Potential in MENA Region – A Case Study
The Middle East and North Africa region countries are rapidly shifting towards adoption of desalination techniques to overcome shortage of freshwater reservoirs. Climatic conditions of the region showed that these areas are arid or semi-arid with higher solar flux which makes them highly suitable for harnessing solar energy. Hence, technology of solar photovoltaic cells coupling with desalination unit is investigated extensively to treat brackish water in Middle East and North Africa region. The large-scale usage of this technology can only be happened by government quick action and subsidies to encourage the installation and commissioning of PV desalination plants or coupling existing ones. This solar desalination technique has been found to be highly environment friendly with no greenhouse gas emission. This review study will provide a road map for the future solar powered desalination plants in Middle East and North Africa region, obstacles in applicability of technique and how to overcome it to ensure a sustainable future water production in Middle East and North Africa region
Groundwater flow modeling: a case study of the Lower Rusizi alluvial plain aquifer, North-Western Burundi
The study area, in northwestern Burundi, is an alluvial plain consisting of fine clayey sands
and coarse sands with mixed lithology. The aquifer of the lower Rusizi plain could be considered as
confined under a clay layer. A 2D horizontal groundwater flow model was developed under steady-state
conditions using the Modflow software. The study aims to determine the most productive
areas of this confined alluvial aquifer and the main aquifer inflow and outflow values together with
the recharge and river–aquifer interactions. The groundwater potential is dependent on the spatial
distribution of hydraulic conductivity and aquifer thickness values providing the local transmissivity
values. The calibrated model made it possible to assess the spatial distribution of the hydraulic
conductivity values at the regional scale, which ranged from 6 x 10-6 (contact between alluvial
plain and Precambrian basement) to 7.5 x 10-3 m/s (coastal barriers). The results also provided the
computed groundwater flow directions and an estimation of the groundwater levels in areas not
yet investigated by drilling. The results of the computed groundwater flow budget allowed us to
deduce that recharge and river–aquifer interaction constitute the main inflow while the downwards
boundaries (where piezometric heads could be prescribed) are the main zones where outflows
occur. The results of this model can be used in the planning of pumping test programs, locating
areas with high groundwater potential to plan water supply for different private and public users.
This predictive tool will contribute to the resolution of problems related to the use and integrated
management of the groundwater resource in this part of Burundi
Estimation quantitative des apports solides au niveau de la retenue du barrage Sidi Mohammed Ben Abdellah sur le bassin versant de Bouregreg (Maroc).
International audienc
Landslides susceptibility assessment using AHP method in Kanyosha watershed (Bujumbura-Burundi): Urbanisation and management impacts
The Kanyosha watershed is unstable due to the presence of several landslides, which occupy about 3% of the study area. They are causing major damage which costs expensive to the Government of Burundi as well as to the population residing there and their properties. Roads, schools, irrigation canals, houses, crop fields, etc., are in danger of collapse. These landslides are mostly naturally occurring but can sometimes be reactivated by heavy rains or human activities during the excavation of building materials from the river bed.In order to carry out this study, we used the multivariate statistical classification with weighting of the responsible parameters of landslides risk to reach the susceptibility map of mass movements in the Kanyosha watershed. Remote sensing, geology, morphometry and bibliography were the data sources for the different parameters. Google Earth images, ortho-photos and field prospecting helped us to identify the landslides needed to validate the susceptibility map.During the fieldwork, we observed 34 landslides of different types, which were superimposed on the mass movements susceptibility map obtained using the Analytic Hierarchy Process (AHP) and compared to previous studies in which the matrix indexing method was used. We found approximately similar results with the consideration of different scales of work. These reasons confirm the validity of the susceptibility map at the level of the Kanyosha watershed, a map which is an essential document for urban planning and land management
Dimension Reduction and Analysis of a 10-Year Physicochemical and Biological Water Database Applied to Water Resources Intended for Human Consumption in the Provence-Alpes-CĂ´te d'Azur Region, France
International audienceThe SISE-Eaux database of water intended for human consumption, archived by the French Regional Health Agency (ARS) since 1990, is a rich source of information. However, more or less regular monitoring over almost 30 years and the multiplication of parameters lead to a sparse matrix (observations Ă— parameters) and a large dimension of the hyperspace of data. These characteristics make it difficult to exploit this database for a synthetic mapping of water quality, and to identify of the processes responsible for its diversity in a complex geological context and anthropized environment. A 10-year period (2006-2016) was selected from the Provence-Alpes-CĂ´te d'Azur region database (PACA, southeastern France). We extracted 5,295 water samples, each with 15 parameters. A treatment by principal component analysis (PCA) followed with orthomax rotation allows for identifying and ranking six principal components (PCs) totaling 75% of the initial information. The association of the parameters with the principal components, and the regional distribution of the PCs make it possible to identify water-rock interactions, bacteriological contamination, redox processes and arsenic occurrence as the main sources of variability. However, the results also highlight a decrease of useful information, a constraint linked to the vast size and diversity of the study area. The development of a relevant tool for the protecting and managing of water resources will require identifying of subsets based on functional landscape units or the grouping of groundwater bodies
Landslides susceptibility assessment using AHP method in Kanyosha watershed (Bujumbura-Burundi): Urbanisation and management impacts
The Kanyosha watershed is unstable due to the presence of several landslides, which occupy about 3% of the study area. They are causing major damage which costs expensive to the Government of Burundi as well as to the population residing there and their properties. Roads, schools, irrigation canals, houses, crop fields, etc., are in danger of collapse. These landslides are mostly naturally occurring but can sometimes be reactivated by heavy rains or human activities during the excavation of building materials from the river bed.In order to carry out this study, we used the multivariate statistical classification with weighting of the responsible parameters of landslides risk to reach the susceptibility map of mass movements in the Kanyosha watershed. Remote sensing, geology, morphometry and bibliography were the data sources for the different parameters. Google Earth images, ortho-photos and field prospecting helped us to identify the landslides needed to validate the susceptibility map.During the fieldwork, we observed 34 landslides of different types, which were superimposed on the mass movements susceptibility map obtained using the Analytic Hierarchy Process (AHP) and compared to previous studies in which the matrix indexing method was used. We found approximately similar results with the consideration of different scales of work. These reasons confirm the validity of the susceptibility map at the level of the Kanyosha watershed, a map which is an essential document for urban planning and land management
L'impact de la décharge d'Oum Azza sur la qualité des eaux souterraines au niveau de la région de Rabat (Maroc)
International audienceA 110 ha dump, located in the Akrach shallow aquifer area in Morocco, was studied in order to characterize the quality of groundwater around the landfill, to delineate the contaminated area and to determine the factors favouring the contamination of groundwater. This dump is located in the city of Oum Azza (15 km south from Rabat), (Map 1). between the Akrach River in the west and the Sidi Mohamed Ben Abdellah Dam in the east. To assess groundwater pollution from this landfill, piezometric monitoring and Hydrochemical analyses were conducted on 22 wells. The results highlight a significant degradation in the groundwater quality, especially in the parts located in the direct vicinity downstream the dump. In the impacted areas, electrical conductivity was above 1100 ÎĽS cm-1, bicarbonates were higher than 508 mg L-1, chlorides, sulphate, and nitrates contents were higher than 850, 200 and 1 mg L-1, respectively. In addition we found high cadmium (50 - 100 ÎĽg L-1) and chromium (40 - 230 ÎĽg L-1) contents, i.e. much higher than the WHO guidelines for drinking or irrigation water. A principal component analysis conducted on this dataset highlights the absence of a prevalent principal component (PC), with the variance distributed across many PCs. The mechanisms responsible for the chemical variance of the hydro system are therefore numerous and fairly balanced in terms of influence. Finally, a hierarchical classification brings out three groups of observations, each group corresponding to a level of pollution.Un vertedero de 110 ha, ubicado sobre el acuĂfero superficial de Akrach en Marruecos, ha sido estudiado para caracterizar a la calidad de las aguas subterráneas al rededor del vertedero, de conocer la extensiĂłn del área contaminada y estudiar a los factores involucrados en esta contaminaciĂłn. El vertedero se ubicado en la ciudad de Um Azza (15 km al sur de Rabat) (mapa 1), entre el rio Akrach al oeste y la represa Sidi Mohaed Ben Abdallah al este. Un control piezĂłmetro y análisis quĂmicos se hicieron sobre 22 pozos para estudiar esta contaminaciĂłn. La calidad del agua es afectada por una contaminaciĂłn importante especialmente en las áreas al contacto cercano del vertedero y aguas abajo de este mismo. En las zonas afectadas la conductividad elĂ©ctrica de las aguas supera 1100 µS.cm-1 , los bicarbonatos superan 508 mg.L-1 , los cloruros, sulfatos y nitratos superan 850,200 y 1 mg.L-1. Además se consiguiĂł alto contenido en cadmio (50-100 µg.L-1) y cromo (40-230 µg.L-1) o sea mucho más que las normas de la OMS para el agua para beber o regar. Un análisis en componentes principales e llevo a cabo sobre el conjunto de datos. No aparece un eje factorial fuerte sino más bien muchos ejes de semejante fuerza, lo que muestra un conjunto de mecanismos de misma fuerza involucrados en la calidad quĂmica de las aguas contaminadas. Una clasificaciĂłn jerárquica ascendente da tres grupos de muestras, cada grupo corresponde a un nivel de contaminaciĂłn
The impact of the Oum Azza landfill on the quality of groundwater at the Rabat region (Morocco)
A 110 ha dump, located in the Akrach shallow aquifer area in Morocco, was studied in order to
characterize the quality of groundwater around the landfill, to delineate the contaminated area
and to determine the factors favouring the contamination of groundwater. This dump is located
in the city of Oum Azza (15 km south from Rabat), (Map 1). between the Akrach River in the
west and the Sidi Mohamed Ben Abdellah Dam in the east. To assess groundwater pollution from
this landfill, piezometric monitoring and Hydrochemical analyses were conducted on 22 wells.
The results highlight a significant degradation in the groundwater quality, especially in the parts
located in the direct vicinity downstream the dump. In the impacted areas, electrical conductivity was above 1100 ÎĽS cm-1, bicarbonates were higher than 508 mg L-1, chlorides, sulphate, and
nitrates contents were higher than 850, 200 and 1 mg L-1, respectively. In addition we found high
cadmium (50 - 100 ÎĽg L-1) and chromium (40 - 230 ÎĽg L-1) contents, i.e. much higher than the
WHO guidelines for drinking or irrigation water. A principal component analysis conducted on
this dataset highlights the absence of a prevalent principal component (PC), with the variance
distributed across many PCs. The mechanisms responsible for the chemical variance of the hydro
system are therefore numerous and fairly balanced in terms of influence. Finally, a hierarchical
classification brings out three groups of observations, each group corresponding to a level of pollution.The impact of the Oum Azza landfill on the quality of groundwater at the Rabat region (Morocco)
L’impact de la decharge d’Oum Azza sur la qualite des eaux souterain region de Rabat (Maroc)
La décharge étudiée est localisée dans la zone de l’aquifère peu profond d’Akrach (Map 1). Elle est
d’une superficie de 110 ha, située sur la commune d’Oum Azza à 15 Km de Rabat, entre la rivière
Akrach à l’ouest et le barrage de Sidi Mohamed Ben Abdellah à l’est. Le but de cette étude est de
caractériser la qualité des eaux souterraines autour de la décharge, de délimiter la zone contaminée et de déterminer les facteurs favorisant la contamination des eaux souterraines. Pour évaluer
la pollution des eaux souterraines due à cette décharge, des analyses de niveau piézométrique et
Hydrochimique ont été réalisées sur 22 puits.
Les résultats des analyses géochimiques montrent une dégradation qualitative importante des
eaux souterraines, en particulier dans les parties situées dans la zone de gradient descendant et
à proximité directe de la décharge. Dans ces zones polluées, nous avons observé les valeurs suivantes: supérieure à 1100 μS/cm en conductivité électrique, 508mg/L en bicarbonates, 850mg/L
et 200mg/L respectivement en chlorures et sulfate, 1mg/L en nitrates, 50 - 100 mg/L en cadmium,
et 40 - 230 μg/L en chrome. Ces concentrations dépassent largement les valeurs standards de l’Organisation Mondiale de la Santé (OMS) pour l’eau potable et l’eau d’irrigation.
Une analyse en composantes principales réalisée sur cet ensemble de données met en évidence
l’absence d’une composante principale (PC) prévalente, la variance étant répartie sur de nombreux PC. Les mécanismes responsables de la variance chimique d’hydro système sont donc
nombreux et assez équilibrés en termes d’influence. Enfin, une classification hiérarchique fait
apparaĂ®tre trois groupes d’observations, chaque groupe correspondant Ă un niveau de pollution.Un vertedero de 110 ha, ubicado sobre el acuĂfero superficial de Akrach en Marruecos, ha sido
estudiado para caracterizar la calidad de las aguas subterráneas alrededor del vertedero, conocer
la extensión del área contaminada y estudiar los factores involucrados en esta contaminación.
El vertedero se emplazĂł en la ciudad de Um Azza (15 km al sur de Rabat), entre el rio Akrach, al
oeste, y la represa Sidi Mohaed Ben Abdallah, al este. Un control piezĂłmetro y análisis quĂmicos
se hicieron sobre 22 pozos para estudiar esta contaminaciĂłn. La calidad del agua es afectada por
una contaminación importante, especialmente en las áreas al contacto cercano del vertedero, y
aguas abajo de este mismo. En las zonas afectadas la conductividad eléctrica de las aguas supera
1100 µS.cm-1, los bicarbonatos superan 508 mg.L-1 , los cloruros, sulfatos y nitratos superan
850,200 y 1 mg.L-1. Además se consiguió alto contenido en cadmio (50-100 µg.L-1) y cromo (40-
230 µg.L-1). En definitiva, se superaron olgadamente los valores estipulados en las normas de la
OMS para el agua potable y de riego.
Un análisis en componentes principales se llevó a cabo sobre el conjunto de datos. No aparece
un eje factorial consistente, sino más bien muchos ejes de importancia similar, lo que muestra
un conjunto de mecanismos de la misma fuerza involucrados en la calidad quĂmica de las aguas
contaminadas. Una clasificación jerárquica ascendente da tres grupos de muestras, cada grupo
corresponde a un nivel de contaminaciĂłn
Determining the Relevant Scale to Analyze the Quality of Regional Groundwater Resources While Combining Groundwater Bodies, Physicochemical and Biological Databases in Southeastern France
International audienceIn France, the data resulting from monitoring water intended for human consumption are integrated into a national database called SISE-Eaux, a useful and relevant tool for studying the quality of raw and distributed water. A previous study carried out on all the data from the Provence-Alpes-CĂ´te d'Azur (PACA) region in south-eastern France (1,061 sampling points, 5,295 analyses and 15 parameters) revealed that the dilution of the information in a heterogeneous environment constitutes an obstacle to the analysis of ongoing processes that are sources of variability. In this article, cross-referencing this information with the compartmentalization into groundwater bodies (MESOs) provides a hydrogeological constraint on the dataset that can help to better define more homogeneous subsets and improve the interpretation. The approach involves 3 steps: (1) A principal component analysis conducted on the whole dataset aimed at eliminating information redundancy; (2) an unsupervised grouping of groundwater bodies having similar sources of variability; (3) a principal component analysis carried out within the main groups and sub-groups identified, aiming to define and prioritize the sources of variability and the associated processes. The results supported by a discriminant analysis and machine learning show that the grouping of MESOs is the best-suited scale to study ongoing processes due to greater homogeneity. One of the 8 main groups identified in PACA, corresponding to the accompanying aquifers of the main rivers, is analyzed by way of illustration. Water-rock interactions, redox processes and their effects on the release of metals, arsenic and fecal contamination along different pathways were specifically identified with varying impacts according to the subgroups. We discussed both the significance of the principal components and the mean values of the bacteriological parameters, which provide information on the causes and on the state of contamination, respectively. Based on the results from two different groups of MESOs, some guidelines in terms of a strategy for the resources quality monitoring are proposed