The present work was conducted in the basin of Laayoun-Dakhla (South Morocco) to: 1) identify the recharge and flow characteristics of the Lower Cretaceous aquifer (LC);and 2) provide information about the mineralizat...The present work was conducted in the basin of Laayoun-Dakhla (South Morocco) to: 1) identify the recharge and flow characteristics of the Lower Cretaceous aquifer (LC);and 2) provide information about the mineralization of aquifer’s water. Isotopic and hydrochemical compositions combined with the geological and hydrogeological settings were used for this purpose. The principal changes in chemical composition of LC groundwater result from mixing with water of deeper circulation. Closer analysis of available chemical data reveals the importance of dissolution/precipitation processes in evolution of groundwater chemistry. Piezometric levels, as well as chemical and isotopic composition of groundwaters, confirm hydraulic connection between the LC and the others aquifers. Overlap of some major characteristics (δ18O, δ2H, Cl-) in this aquifer suggests that mixing processes considerably influence the hydrochemical evolution of water. The surface electrical resistivity does not indicate any freshwater-saltwater interface in the coastal aquifer and the relationship between 18O and Cl allows us to reject the hypothesis of a seawater intrusion.展开更多
Identification of water potential areas in arid regions is a crucial element for the enhancement of their water resources and socio-economic development. In fact, water resources system-planning can be used to make va...Identification of water potential areas in arid regions is a crucial element for the enhancement of their water resources and socio-economic development. In fact, water resources system-planning can be used to make various decisions and implement manage- ment of water resources policies. The purpose of this study is to identify groundwater sto- rage areas in the high Guir Basin by implementing Geographic Information System (GIS) and Remote Sensing methods. The required data for this study can be summarized into five critical factors: Topography (slope), lithology, rainfall, rock fracture and drainage. These critical factors have been converted by the GIS into thematic maps. For each cri- tical parameter, a coefficient with weight was attributed according to its importance. The map of potential groundwater storage areas is obtained by adding the products (coeffi- cient × weight) of the five parameters. The results show that 50% to 64% of the total area of the High Guir Basin is potentially rich in groundwater, where most of fracture systems are intensely developed. The obtained results are validated with specific yield of the aqui- fer in the study area. It is noted that there is a strong positive correlation between excel- lent groundwater potential zones with high flows of water points and it diminishes with low specific yield with poor potential zones.展开更多
The high Ziz’s basin, which is part of the Central High Atlas, contains Jurassic superficial and deep aquifers. The information sheets are still fragmentary and insufficient because of the basin’s large size and its...The high Ziz’s basin, which is part of the Central High Atlas, contains Jurassic superficial and deep aquifers. The information sheets are still fragmentary and insufficient because of the basin’s large size and its complex geological structure. In order to improve the knowledge of these aquifers and the determination of the structure of aquifers, a 3D geological model was developed in this study. It was constructed from information provided by 200 mechanical soundings and 81 electrical surveys and geological maps. Compiled holes were analyzed, coded and integrated in the software Groundwater Modeling System 6.0 (GMS 6.0). For doing this, five lithostratigraphic units were considered: the Domerian, the Toarcian, the Aalenian, the Bajo-Bathonian and the Quaternary. The operation of the 3D stratigraphic model allowed making it closer to the geometry of Jurassic aquifers.展开更多
We present a comparative analysis of electrical and gravity data on the Geographic Information System of the prerifaines ridges. At the Meso-Cenozo?c sequence, the geometry of the prerifaines ridges is fairly well kno...We present a comparative analysis of electrical and gravity data on the Geographic Information System of the prerifaines ridges. At the Meso-Cenozo?c sequence, the geometry of the prerifaines ridges is fairly well known. However, the post-Miocene series remain to be characterized. In this perspective, we use a database composed of gravity and vertical electrical sounding profiles and geo-electrical sections in order to characterize this structuration. These data are calibrated by many oil and hydrogeological boreholes. Preliminary results lead to better understanding of the organization of its underlying structures in this area. The Gravimetric filtering results show that the area may be dissected by tree major faults striking NW-SE, NE-SW and N-S. All these faults have contributed, since Hercynian to Alpines orogenies, to the structuring of this area, being proved to be the deepest and can reach 4500 m. The comparison of gravity maps, geological and structural maps under Geographic Information System allows the identification of major structural directions and trends of the study area. It confirms some structural elements gathered from outcrops and define new ones. Results from this work show the importance of using various filtering and interpretation techniques in the analysis of gravity data. They also provide news insights into the deep structure of the study area.展开更多
Lizardite rich peridotite has never been used to prepare ceramic specimens,especially in Morocco.For this raison,potential use of naturally abundant lizarditic material from the Rif domain,as a supply for ceramic indu...Lizardite rich peridotite has never been used to prepare ceramic specimens,especially in Morocco.For this raison,potential use of naturally abundant lizarditic material from the Rif domain,as a supply for ceramic industry,has been evaluated.The effects of lizardite addition to magnesite and dolomite mixtures on the thermomechanical properties of the calcined ceramics were also detailed.To achieve this target,natural lizardite,magnesite and dolomite samples were collected in ultrabasic Beni Bousra massif.Those raw samples were used for the synthesis of a forsterite-monticellite rich ceramics.Both raw and sintered samples were characterized by x-ray diffraction,scanning electron microscope and fourier transform infrared.The obtained results showed that both magnesite and dolomite were mainly composed of MgCO_(3) and CaCO_(3).In contrast,lizardite sample showed high amounts of SiO_(2),MgO and Fe2O_(3).An increased amount of lizardite in the initial mixtures enhanced mechanical and dimensional properties of the prepared ceramic specimens,and subsequently,the production of ceramics with the required technological properties.Thus,the preparation of Moroccan lizardite-based ceramics is technically feasible,economically justifiable and socially desirable due to the contribution to the economic growth of the raw materials sector,especially ceramic industry.展开更多
Soil organic matter (SOM) is a fundamental soil constituent. The estimation of this parameter in the laboratory using the classical method is complex time-consuming and requires the use of chemical re-agents. The obje...Soil organic matter (SOM) is a fundamental soil constituent. The estimation of this parameter in the laboratory using the classical method is complex time-consuming and requires the use of chemical re-agents. The objectives of this study were to assess the accuracy of two laboratory measurement setups of the VIS-NIR spectroscopy in estimating SOM content and determine the important spectral bands in the SOM estimation model. A total of 115 soil samples were collected from the non-root zone (0-20 cm) of soil in the study area of the Triffa Plain and then analysed for SOM in the laboratory by the Walkley-Black method. The reflectance spectra of soil samples were measured by two protocols, Contact Probe (CP) and Pistol Grip (PG)) of the ASD spectroradiometer (350-2500 nm) in the laboratory. Partial least squares regression (PLSR) was used to develop the prediction models. The results of coefficient of determination (R2) and the root mean square error (RMSE) showed that the pistol grip offers reasonable accuracy with an R2=0.93 and RMSE=0.13 compared to the contact probe protocol with an R2=0.85 and RMSE = 0.19. The near-Infrared range were more accurate than those in the visible range for pre-dicting SOM using the both setups (CP and PG). The significant wavelengths contributing to the pre-diction of SOM for (PG) setup were at:424, 597, 1432, 1484, 1830,1920, 2200, 2357 and 2430 nm, while were at 433, 587, 1380, 1431, 1929, 2200 and 2345 nm for (CP) setup.展开更多
文摘The present work was conducted in the basin of Laayoun-Dakhla (South Morocco) to: 1) identify the recharge and flow characteristics of the Lower Cretaceous aquifer (LC);and 2) provide information about the mineralization of aquifer’s water. Isotopic and hydrochemical compositions combined with the geological and hydrogeological settings were used for this purpose. The principal changes in chemical composition of LC groundwater result from mixing with water of deeper circulation. Closer analysis of available chemical data reveals the importance of dissolution/precipitation processes in evolution of groundwater chemistry. Piezometric levels, as well as chemical and isotopic composition of groundwaters, confirm hydraulic connection between the LC and the others aquifers. Overlap of some major characteristics (δ18O, δ2H, Cl-) in this aquifer suggests that mixing processes considerably influence the hydrochemical evolution of water. The surface electrical resistivity does not indicate any freshwater-saltwater interface in the coastal aquifer and the relationship between 18O and Cl allows us to reject the hypothesis of a seawater intrusion.
文摘Identification of water potential areas in arid regions is a crucial element for the enhancement of their water resources and socio-economic development. In fact, water resources system-planning can be used to make various decisions and implement manage- ment of water resources policies. The purpose of this study is to identify groundwater sto- rage areas in the high Guir Basin by implementing Geographic Information System (GIS) and Remote Sensing methods. The required data for this study can be summarized into five critical factors: Topography (slope), lithology, rainfall, rock fracture and drainage. These critical factors have been converted by the GIS into thematic maps. For each cri- tical parameter, a coefficient with weight was attributed according to its importance. The map of potential groundwater storage areas is obtained by adding the products (coeffi- cient × weight) of the five parameters. The results show that 50% to 64% of the total area of the High Guir Basin is potentially rich in groundwater, where most of fracture systems are intensely developed. The obtained results are validated with specific yield of the aqui- fer in the study area. It is noted that there is a strong positive correlation between excel- lent groundwater potential zones with high flows of water points and it diminishes with low specific yield with poor potential zones.
文摘The high Ziz’s basin, which is part of the Central High Atlas, contains Jurassic superficial and deep aquifers. The information sheets are still fragmentary and insufficient because of the basin’s large size and its complex geological structure. In order to improve the knowledge of these aquifers and the determination of the structure of aquifers, a 3D geological model was developed in this study. It was constructed from information provided by 200 mechanical soundings and 81 electrical surveys and geological maps. Compiled holes were analyzed, coded and integrated in the software Groundwater Modeling System 6.0 (GMS 6.0). For doing this, five lithostratigraphic units were considered: the Domerian, the Toarcian, the Aalenian, the Bajo-Bathonian and the Quaternary. The operation of the 3D stratigraphic model allowed making it closer to the geometry of Jurassic aquifers.
文摘We present a comparative analysis of electrical and gravity data on the Geographic Information System of the prerifaines ridges. At the Meso-Cenozo?c sequence, the geometry of the prerifaines ridges is fairly well known. However, the post-Miocene series remain to be characterized. In this perspective, we use a database composed of gravity and vertical electrical sounding profiles and geo-electrical sections in order to characterize this structuration. These data are calibrated by many oil and hydrogeological boreholes. Preliminary results lead to better understanding of the organization of its underlying structures in this area. The Gravimetric filtering results show that the area may be dissected by tree major faults striking NW-SE, NE-SW and N-S. All these faults have contributed, since Hercynian to Alpines orogenies, to the structuring of this area, being proved to be the deepest and can reach 4500 m. The comparison of gravity maps, geological and structural maps under Geographic Information System allows the identification of major structural directions and trends of the study area. It confirms some structural elements gathered from outcrops and define new ones. Results from this work show the importance of using various filtering and interpretation techniques in the analysis of gravity data. They also provide news insights into the deep structure of the study area.
文摘Lizardite rich peridotite has never been used to prepare ceramic specimens,especially in Morocco.For this raison,potential use of naturally abundant lizarditic material from the Rif domain,as a supply for ceramic industry,has been evaluated.The effects of lizardite addition to magnesite and dolomite mixtures on the thermomechanical properties of the calcined ceramics were also detailed.To achieve this target,natural lizardite,magnesite and dolomite samples were collected in ultrabasic Beni Bousra massif.Those raw samples were used for the synthesis of a forsterite-monticellite rich ceramics.Both raw and sintered samples were characterized by x-ray diffraction,scanning electron microscope and fourier transform infrared.The obtained results showed that both magnesite and dolomite were mainly composed of MgCO_(3) and CaCO_(3).In contrast,lizardite sample showed high amounts of SiO_(2),MgO and Fe2O_(3).An increased amount of lizardite in the initial mixtures enhanced mechanical and dimensional properties of the prepared ceramic specimens,and subsequently,the production of ceramics with the required technological properties.Thus,the preparation of Moroccan lizardite-based ceramics is technically feasible,economically justifiable and socially desirable due to the contribution to the economic growth of the raw materials sector,especially ceramic industry.
基金The authors acknowledge the facilities and financial supports provided by the Mohammed First University and the National Institute of Agronomic Research(INRA)of Oujda.I want to thank all researchers of the Applied Geosciences Laboratory and all re-searchers of INRA for his help in collecting the soil samples and their analysis in the laboratory
文摘Soil organic matter (SOM) is a fundamental soil constituent. The estimation of this parameter in the laboratory using the classical method is complex time-consuming and requires the use of chemical re-agents. The objectives of this study were to assess the accuracy of two laboratory measurement setups of the VIS-NIR spectroscopy in estimating SOM content and determine the important spectral bands in the SOM estimation model. A total of 115 soil samples were collected from the non-root zone (0-20 cm) of soil in the study area of the Triffa Plain and then analysed for SOM in the laboratory by the Walkley-Black method. The reflectance spectra of soil samples were measured by two protocols, Contact Probe (CP) and Pistol Grip (PG)) of the ASD spectroradiometer (350-2500 nm) in the laboratory. Partial least squares regression (PLSR) was used to develop the prediction models. The results of coefficient of determination (R2) and the root mean square error (RMSE) showed that the pistol grip offers reasonable accuracy with an R2=0.93 and RMSE=0.13 compared to the contact probe protocol with an R2=0.85 and RMSE = 0.19. The near-Infrared range were more accurate than those in the visible range for pre-dicting SOM using the both setups (CP and PG). The significant wavelengths contributing to the pre-diction of SOM for (PG) setup were at:424, 597, 1432, 1484, 1830,1920, 2200, 2357 and 2430 nm, while were at 433, 587, 1380, 1431, 1929, 2200 and 2345 nm for (CP) setup.
