Energy Sources Part a Recovery Utilization and Environmental Effects, 2009
ABSTRACT The present study addresses the efficiency of an integrated air sparging, soil vapor ext... more ABSTRACT The present study addresses the efficiency of an integrated air sparging, soil vapor extraction, and pump and treat system in the remediation of a diesel contaminated site in Oman. Cleanup efforts have targeted groundwater and soil in fractured formations. Site hydrogeological characterization was conducted including sampling and analysis of water and soil. Within seven months of the start of the treatment system, benzene gas in the unsaturated zone fell from an initial range of 15–60 ppm to below detection level, while total petroleum hydrocarbon in the groundwater dropped from 25–50 ppm to less than 0.5 ppm. Treatment processes have ceased while groundwater and soil are being monitored. Thus far, benzene gas has been undetected for the past 18 months, but total petroleum hydrocarbon in groundwater has rebounded to 1.2 ppm during the last four months.
The present study assesses groundwater resources in the semiarid central Sudan, where 20 deep pro... more The present study assesses groundwater resources in the semiarid central Sudan, where 20 deep productive wells were installed to supply a major city in the region, El Obeid. The wells, which has an average 20 L/s discharge each, are taping a deep semiconfined to confined aquifer of fluvial silisiclastics deposited in the Tertiary-Pleistocene. Groundwater modeling was used as a technique to interpret the hydrologic system in arid to semiarid central Sudan and to simulate the future influence of the project on the hydrogeologic system. The simulation confirmed that steady-state flow conditions have been currently reached as indicated by consistency of computed heads. It also calibrated the values of the conductivity and recharge and ensured the sustainability of the El Obeid water supply project. A total of 3.5×10 7 m 3 /year can be continually extracted from the deep aquifer to supply El Obeid city without endangering the groundwater resources in the region. The decline in water level will not exceed 25 m during the first 10 years, while indefinite continuous pumping will affect only the vicinity of the wells in a circle of 30 km diameter. Therefore, aquifer storage capacity and hydraulic properties encourage further groundwater exploitation. The present use of groundwater is extremely lower than the present demand, and it can potentially cover future demands without introducing significant changes to the system. The increase of pumping cost due to the decline in head subsequent to project operation was found to be minimal and of local effect.
Deuterium, oxygen-18 and chloride were analyzed for 84 samples from deep and shallow wells, preci... more Deuterium, oxygen-18 and chloride were analyzed for 84 samples from deep and shallow wells, precipitation and the river White Nile to investigate groundwater recharge/discharge relations in the semi-arid central Sudan. Spatial and vertical variation in isotopic signature and chloride concentration in the groundwater show similar patterns and indicate local recharge and evaporative discharge. Progressive decrease in isotopic composition along the
Page 1. ORIGINAL ARTICLE Fluids' dynamics in transient air sparging of a heterogeneous uncon... more Page 1. ORIGINAL ARTICLE Fluids' dynamics in transient air sparging of a heterogeneous unconfined aquifer Rashid S. Al-Maamari Akihiko Hirayama Tsuyoshi Shiga Mark N. Sueyoshi Mahfoodh Al-Shuely Osman AE Abdalla Anvar R. Kacimov ...
Groundwater recharge & discharge relations inferred from isotopes and hydrochemistry in Samail Ca... more Groundwater recharge & discharge relations inferred from isotopes and hydrochemistry in Samail Catchment, Oman OSMAN ABDALLA1, TALAL AL-HOSNI2, ABDULLH ALRAWAHI3 1Sultan Qaboos University, Dept. of Earthsciences, P.O. Box 36, Oman osman@squ,edu.om (* presenting author) 2Sultan Qaboos University, Dept. of Earthsciences, P.O. Box 36, Oman 3Ministry of Regional Municipalities & Ware Resources, Alkhwair, Oman Abstract Groundwater recharge and discharge relation along the flow path in the regional catchment of Samail, Oman has been investigated using different isotopes and conventional hydrochemistry. The subsurface geology is complex and variable ranging from karstified carbonate rocks at the elevated areas of North Oman Mountains (NOM) to fractured ophiolitic sequence overlain by porous medium of Quaternary alluvium gravel at the top of the geologic section. The alluvium is thickening from elevated area downstream to exceed 300 m at the lower reaches of the catchment. The boundary betw...
ABSTRACT One-third of the population of Oman depends on the groundwater extracted from the alluvi... more ABSTRACT One-third of the population of Oman depends on the groundwater extracted from the alluvium deposits located along the coast of the Gulf of Oman. However, groundwater depletion and seawater intrusion constitute major challenges along the coastal water accumulations in Oman. The objective of this study is to locate the extent of seawater intrusion and to map the shallow alluvial aquifer in the region, where water accumulates from the rain or the flooding at AlKhod dam. In order to assess the effect of groundwater infiltration, which recharges the aquifer and fights the seawater invasion, a quantitative approach for the groundwater quality and distribution is required to provide reasonable knowledge on the spatial distribution of the aquifers, their thickness and the type of sediments. When groundwater wells and their subsurface geologic and electrical logs are not available or not deep enough, surface geophysical surveys can be considered due to their low cost and short acquisition time. The application of time-domain electromagnetic (TDEM) method in Al-Khod area, Oman has proven to be a successful tool in mapping the fresh/saline water interface and for locating the depth of fresh water aquifer. The depths and inland extents of the saline zone were mapped along three N–S TDEM profiles. The depths to the freshwater table and saline interface calculated from TDEM closely match the available well data.
ABSTRACT The presence of heavy metals in landfill leachate pose a risk to the environment especia... more ABSTRACT The presence of heavy metals in landfill leachate pose a risk to the environment especially in unlined landfills where dissipation of leachate into ground water might occur. This study is focused on the assessment of heavy metals in leachate of Al Amerat unlined landfill in the Sultanate of Oman. Leachate samples were collected from leachate pools located behind the landfill and analyzed using the standard methods. Results showed that certain heavy metals found in leachate were exceeding the drinking water standards and waste water re-use and discharge standards of the Sultanate. Al, V, Cr, Mn, Co, Ni, Ba, Pb and Fe were all above the standards in concentrations of 2.050 mg/l, 0.9775 mg/l, 2.800 mg/l, 0.503 mg/l, 0.128 mg/l, 0.773 mg/l, 0.8575 mg/l, 0.130 mg/l, and 39.25 mg/l, respectively. The effect of these contaminants should be considered as surface and ground water contamination might occur. Rehabilitation of such unlined landfills should take place with continuous monitoring programs of ground water sources around the area to contain any contamination that might occur.
Page 1. ORIGINAL ARTICLE Fluids' dynamics in transient air sparging of a heterogeneous uncon... more Page 1. ORIGINAL ARTICLE Fluids' dynamics in transient air sparging of a heterogeneous unconfined aquifer Rashid S. Al-Maamari Akihiko Hirayama Tsuyoshi Shiga Mark N. Sueyoshi Mahfoodh Al-Shuely Osman AE Abdalla Anvar R. Kacimov ...
The use of cyanide (CN), which is characterized by volatility, toxicity and high odor, in gold mi... more The use of cyanide (CN), which is characterized by volatility, toxicity and high odor, in gold mining is scarcely addressed in the literature and remain controversial. Environmentalists oppose CN usage as it potentially poses serious environmental threats, whereas economic and mining geologists are in favor of its usage for its extracting capacity and economic feasibility. The present study investigates the possible dispersion of CN into groundwater resources caused by a gold mine (ca. 15 years old) located in the arid area of Yanqul, North Oman. The gold is hosted in gossan deposits associated with ophiolitic rocks and sulfide deposits. Sodium cyanide is mixed with 0.5 m 3 of water and then added to a tonne of crushed ore rock to extract 6 g of gold mineral. The final residues are dumped in engineered, lined and uncovered tailing dams. Subsequent to rainfall water draining the mine plateau flows along the wadies and percolates into the shallow Quaternary alluvium aquifer. Hence, groundwater samples were collected from 16 piezometers adjacent to and around the mine. The samples were analyzed for CN using the revised phenolphthalin method and they all show CN concentration below the detection limit (5 ppb). The samples were also analyzed for heavy metals to investigate the potential of CN complexation. Most of heavy metals indicated very trace concentration. The absence of CN in groundwater is attributed to volatilization of CN (converted to HCN), lined dam structure, high evapotranspiration rate and deeper water table. This finding is consistent with the historical CN analysis in the groundwater and solid wastes. It can be pointed out that within few years of operation well engineered tailing dams can provide safe structure preventing CN-groundwater pollution in arid areas. Potential threats to the air and soil are not addressed in this article.
Groundwater depletion and seawater intrusion constitute major challenges along coastal aquifers i... more Groundwater depletion and seawater intrusion constitute major challenges along coastal aquifers in arid areas. This paper assesses the role of groundwater recharge dams constructed to replenish aquifers and fight seawater intrusion with reference to AlKhod dam, Oman, sited 7 km from the coast on a gravely unconfined aquifer. Water table rise in piezometers located downstream from the dam shows regular patterns correlating with magnitude of wadi flow, whereas upstream piezometers show irregular patterns. Controlled release of water captured by the dam optimizes water percolation and enhances artificial recharge which was estimated in the wet years 1997, 2003 and 2005 as 15, 22 and 27 Mm 3 , respectively, using water table fluctuation method. Recharge contributed 40-60 % of the total annual abstraction. Groundwater salinity increased in the 1980s and 1990s and the saline/freshwater interface advanced inland, but has receded partially after 1997 (highest rainfall) and completely after 2005 indicated by reduction in electrical conductivity and thickening of freshwater lens. The recession is attributed to the dam's induced recharge and reduction of pumping in 2004 following the commissioning of Barka desalination plant. Integrating artificial recharge with groundwater resources management is therefore an effective measure to replenish aquifers in arid areas and mitigate seawater intrusion along the coasts.
Urban water in Gulf Cooperation Council countries is principally supplied from desalination plant... more Urban water in Gulf Cooperation Council countries is principally supplied from desalination plants. However, desalination could be interrupted by natural hazards such as cyclones or harmful algal blooms. Four scenarios have been considered to help public institutions in Muscat to establish a water strategy for emergency situations. The numerical simulations of groundwater pumping have shown that the aquifer can supply emergency water in a safe way without any apparent risk of seawater intrusion to the Al-Khod Aquifer. The results show that Muscat can be easily supplied by emergency groundwater for up to 10 consecutive days with volumes varying between 24 and 71 l/cap/day at a low cost of US$0.18 per m 3 . Covering up to 66% of the total regular demand during an emergency is technically feasible but would bring the cost up to US$1.49 per m 3 for groundwater and a cost of US$38.6 per m 3 for storage reservoirs made of concrete. The cost per m 3 of using concrete reservoirs is close to the market price of bottled water. Finally, the Public Authority for Electricity and Water might think of decentralizing the water storage at house levels by requiring new houses to be equipped with reservoirs on the roofs.
Younger groundwater found in some Omani aquifers is a result of recent recharge from cyclonic and... more Younger groundwater found in some Omani aquifers is a result of recent recharge from cyclonic and storm events [Weyhenmeyer et al. (Science 287:842-845, 2000); Young et al. (J Appl Geophys 57:43-61, 2004)]. The analysis of the meteorological data in Oman indicates an anomalous rainfall on a decadal interval whereas cyclones frequency is expected to increase due to global climatic changes. The cyclone Gonu has severely struck the eastern Omani coasts in 2007 resulting in devastating floods. Huge volume of water (3,672 mm 3 ) spread over the coastal plain calling for an assessment of potential groundwater recharge subsequent to this event. The present study evaluates groundwater recharge with respect to Gonu 2007 to assess the potential of recharge induced by such cyclones in the arid zones. The hydrographs of several piezometers sited along the coastal plain in Muscat Province have been studied and variation in water table rise has been analyzed. Significant water table rise is indicated for areas with geological and structural settings favoring rapid infiltration of water yielding considerable groundwater mound, whereas piezometers located in less favorable zones show minimum rise of water table. However, soon after the floods the aquifer hydrodynamics has readjusted to attain equilibrium and the groundwater mound dissipated. The cumulative rise of the water table on an areal extent does not exceed a few centimeters indicating lesser volume of recharge. Comparatively, recharge from frequent precipitation along favorable zones produces more significant recharge compared with cyclonic events where surface water residence time is shorter to allow for efficient infiltration.
ABSTRACT Assessment of recharge zones of strategic aquifers in Northern Oman calls for quantifica... more ABSTRACT Assessment of recharge zones of strategic aquifers in Northern Oman calls for quantification of groundwater hydraulics in alluvial fans with a subjacent bedrock of various geometry. Unlike standard analytical solutions to a 2-D unconfined flow over a tilted bedrock and a common Dupuit–Forchheimer approximation we derive novel analytical solutions for subjacent confining layer of a non-constant slope or a bedding inconformity. We use a genuine 2-D flow model, conformal mappings and inverse boundary-value problems methods. For flow over an arbitrary corner the vertex is either a stagnation point or point of infinite Darcian velocity. The hodograph domain (a circular triangle) is mapped onto a complex potential strip via an auxiliary half-plane. A non-planar aquifuge is also reconstructed as a streamline, along which an additional “control” boundary condition holds (pore pressure as a function of an auxiliary variable).
The present study applies Darcy's Law to compute evapotranspiration in the arid to semi-arid... more The present study applies Darcy's Law to compute evapotranspiration in the arid to semi-arid central Sudan. The average decline in groundwater level (s) along a distance (L) of the aquifer's cross section was calculated. Such decline is a function of discharge Q at any point across the unit width of the aquifer and effective porosity. Groundwater in the study area generally flows from NW to the SE along basin axial trough and is characterized by variable hydraulic gradient. As the aquifer discharge is directly proportional to the gradient, different values of groundwater level decline were calculated along the flow direction. The hydrogeological map constructed during this study indicates that the system is hydrologicaly closed and groundwater doesn't discharge in the neighboring White Nile River. Geological, hydrological and climatological settings of the discharge area demonstrate that evapotranspiration is the main mechanism of groundwater discharge and reveals tha...
Abstract The present study determines the source of dust particles and investigates their impact ... more Abstract The present study determines the source of dust particles and investigates their impact on the chemical compositions of plants and soils around a cement factory in Oman within a radius of 10 km of this disturbed ecosystem. A total number of nine samples of the species of ...
Energy Sources Part a Recovery Utilization and Environmental Effects, 2009
ABSTRACT The present study addresses the efficiency of an integrated air sparging, soil vapor ext... more ABSTRACT The present study addresses the efficiency of an integrated air sparging, soil vapor extraction, and pump and treat system in the remediation of a diesel contaminated site in Oman. Cleanup efforts have targeted groundwater and soil in fractured formations. Site hydrogeological characterization was conducted including sampling and analysis of water and soil. Within seven months of the start of the treatment system, benzene gas in the unsaturated zone fell from an initial range of 15–60 ppm to below detection level, while total petroleum hydrocarbon in the groundwater dropped from 25–50 ppm to less than 0.5 ppm. Treatment processes have ceased while groundwater and soil are being monitored. Thus far, benzene gas has been undetected for the past 18 months, but total petroleum hydrocarbon in groundwater has rebounded to 1.2 ppm during the last four months.
The present study assesses groundwater resources in the semiarid central Sudan, where 20 deep pro... more The present study assesses groundwater resources in the semiarid central Sudan, where 20 deep productive wells were installed to supply a major city in the region, El Obeid. The wells, which has an average 20 L/s discharge each, are taping a deep semiconfined to confined aquifer of fluvial silisiclastics deposited in the Tertiary-Pleistocene. Groundwater modeling was used as a technique to interpret the hydrologic system in arid to semiarid central Sudan and to simulate the future influence of the project on the hydrogeologic system. The simulation confirmed that steady-state flow conditions have been currently reached as indicated by consistency of computed heads. It also calibrated the values of the conductivity and recharge and ensured the sustainability of the El Obeid water supply project. A total of 3.5×10 7 m 3 /year can be continually extracted from the deep aquifer to supply El Obeid city without endangering the groundwater resources in the region. The decline in water level will not exceed 25 m during the first 10 years, while indefinite continuous pumping will affect only the vicinity of the wells in a circle of 30 km diameter. Therefore, aquifer storage capacity and hydraulic properties encourage further groundwater exploitation. The present use of groundwater is extremely lower than the present demand, and it can potentially cover future demands without introducing significant changes to the system. The increase of pumping cost due to the decline in head subsequent to project operation was found to be minimal and of local effect.
Deuterium, oxygen-18 and chloride were analyzed for 84 samples from deep and shallow wells, preci... more Deuterium, oxygen-18 and chloride were analyzed for 84 samples from deep and shallow wells, precipitation and the river White Nile to investigate groundwater recharge/discharge relations in the semi-arid central Sudan. Spatial and vertical variation in isotopic signature and chloride concentration in the groundwater show similar patterns and indicate local recharge and evaporative discharge. Progressive decrease in isotopic composition along the
Page 1. ORIGINAL ARTICLE Fluids' dynamics in transient air sparging of a heterogeneous uncon... more Page 1. ORIGINAL ARTICLE Fluids' dynamics in transient air sparging of a heterogeneous unconfined aquifer Rashid S. Al-Maamari Akihiko Hirayama Tsuyoshi Shiga Mark N. Sueyoshi Mahfoodh Al-Shuely Osman AE Abdalla Anvar R. Kacimov ...
Groundwater recharge & discharge relations inferred from isotopes and hydrochemistry in Samail Ca... more Groundwater recharge & discharge relations inferred from isotopes and hydrochemistry in Samail Catchment, Oman OSMAN ABDALLA1, TALAL AL-HOSNI2, ABDULLH ALRAWAHI3 1Sultan Qaboos University, Dept. of Earthsciences, P.O. Box 36, Oman osman@squ,edu.om (* presenting author) 2Sultan Qaboos University, Dept. of Earthsciences, P.O. Box 36, Oman 3Ministry of Regional Municipalities & Ware Resources, Alkhwair, Oman Abstract Groundwater recharge and discharge relation along the flow path in the regional catchment of Samail, Oman has been investigated using different isotopes and conventional hydrochemistry. The subsurface geology is complex and variable ranging from karstified carbonate rocks at the elevated areas of North Oman Mountains (NOM) to fractured ophiolitic sequence overlain by porous medium of Quaternary alluvium gravel at the top of the geologic section. The alluvium is thickening from elevated area downstream to exceed 300 m at the lower reaches of the catchment. The boundary betw...
ABSTRACT One-third of the population of Oman depends on the groundwater extracted from the alluvi... more ABSTRACT One-third of the population of Oman depends on the groundwater extracted from the alluvium deposits located along the coast of the Gulf of Oman. However, groundwater depletion and seawater intrusion constitute major challenges along the coastal water accumulations in Oman. The objective of this study is to locate the extent of seawater intrusion and to map the shallow alluvial aquifer in the region, where water accumulates from the rain or the flooding at AlKhod dam. In order to assess the effect of groundwater infiltration, which recharges the aquifer and fights the seawater invasion, a quantitative approach for the groundwater quality and distribution is required to provide reasonable knowledge on the spatial distribution of the aquifers, their thickness and the type of sediments. When groundwater wells and their subsurface geologic and electrical logs are not available or not deep enough, surface geophysical surveys can be considered due to their low cost and short acquisition time. The application of time-domain electromagnetic (TDEM) method in Al-Khod area, Oman has proven to be a successful tool in mapping the fresh/saline water interface and for locating the depth of fresh water aquifer. The depths and inland extents of the saline zone were mapped along three N–S TDEM profiles. The depths to the freshwater table and saline interface calculated from TDEM closely match the available well data.
ABSTRACT The presence of heavy metals in landfill leachate pose a risk to the environment especia... more ABSTRACT The presence of heavy metals in landfill leachate pose a risk to the environment especially in unlined landfills where dissipation of leachate into ground water might occur. This study is focused on the assessment of heavy metals in leachate of Al Amerat unlined landfill in the Sultanate of Oman. Leachate samples were collected from leachate pools located behind the landfill and analyzed using the standard methods. Results showed that certain heavy metals found in leachate were exceeding the drinking water standards and waste water re-use and discharge standards of the Sultanate. Al, V, Cr, Mn, Co, Ni, Ba, Pb and Fe were all above the standards in concentrations of 2.050 mg/l, 0.9775 mg/l, 2.800 mg/l, 0.503 mg/l, 0.128 mg/l, 0.773 mg/l, 0.8575 mg/l, 0.130 mg/l, and 39.25 mg/l, respectively. The effect of these contaminants should be considered as surface and ground water contamination might occur. Rehabilitation of such unlined landfills should take place with continuous monitoring programs of ground water sources around the area to contain any contamination that might occur.
Page 1. ORIGINAL ARTICLE Fluids' dynamics in transient air sparging of a heterogeneous uncon... more Page 1. ORIGINAL ARTICLE Fluids' dynamics in transient air sparging of a heterogeneous unconfined aquifer Rashid S. Al-Maamari Akihiko Hirayama Tsuyoshi Shiga Mark N. Sueyoshi Mahfoodh Al-Shuely Osman AE Abdalla Anvar R. Kacimov ...
The use of cyanide (CN), which is characterized by volatility, toxicity and high odor, in gold mi... more The use of cyanide (CN), which is characterized by volatility, toxicity and high odor, in gold mining is scarcely addressed in the literature and remain controversial. Environmentalists oppose CN usage as it potentially poses serious environmental threats, whereas economic and mining geologists are in favor of its usage for its extracting capacity and economic feasibility. The present study investigates the possible dispersion of CN into groundwater resources caused by a gold mine (ca. 15 years old) located in the arid area of Yanqul, North Oman. The gold is hosted in gossan deposits associated with ophiolitic rocks and sulfide deposits. Sodium cyanide is mixed with 0.5 m 3 of water and then added to a tonne of crushed ore rock to extract 6 g of gold mineral. The final residues are dumped in engineered, lined and uncovered tailing dams. Subsequent to rainfall water draining the mine plateau flows along the wadies and percolates into the shallow Quaternary alluvium aquifer. Hence, groundwater samples were collected from 16 piezometers adjacent to and around the mine. The samples were analyzed for CN using the revised phenolphthalin method and they all show CN concentration below the detection limit (5 ppb). The samples were also analyzed for heavy metals to investigate the potential of CN complexation. Most of heavy metals indicated very trace concentration. The absence of CN in groundwater is attributed to volatilization of CN (converted to HCN), lined dam structure, high evapotranspiration rate and deeper water table. This finding is consistent with the historical CN analysis in the groundwater and solid wastes. It can be pointed out that within few years of operation well engineered tailing dams can provide safe structure preventing CN-groundwater pollution in arid areas. Potential threats to the air and soil are not addressed in this article.
Groundwater depletion and seawater intrusion constitute major challenges along coastal aquifers i... more Groundwater depletion and seawater intrusion constitute major challenges along coastal aquifers in arid areas. This paper assesses the role of groundwater recharge dams constructed to replenish aquifers and fight seawater intrusion with reference to AlKhod dam, Oman, sited 7 km from the coast on a gravely unconfined aquifer. Water table rise in piezometers located downstream from the dam shows regular patterns correlating with magnitude of wadi flow, whereas upstream piezometers show irregular patterns. Controlled release of water captured by the dam optimizes water percolation and enhances artificial recharge which was estimated in the wet years 1997, 2003 and 2005 as 15, 22 and 27 Mm 3 , respectively, using water table fluctuation method. Recharge contributed 40-60 % of the total annual abstraction. Groundwater salinity increased in the 1980s and 1990s and the saline/freshwater interface advanced inland, but has receded partially after 1997 (highest rainfall) and completely after 2005 indicated by reduction in electrical conductivity and thickening of freshwater lens. The recession is attributed to the dam's induced recharge and reduction of pumping in 2004 following the commissioning of Barka desalination plant. Integrating artificial recharge with groundwater resources management is therefore an effective measure to replenish aquifers in arid areas and mitigate seawater intrusion along the coasts.
Urban water in Gulf Cooperation Council countries is principally supplied from desalination plant... more Urban water in Gulf Cooperation Council countries is principally supplied from desalination plants. However, desalination could be interrupted by natural hazards such as cyclones or harmful algal blooms. Four scenarios have been considered to help public institutions in Muscat to establish a water strategy for emergency situations. The numerical simulations of groundwater pumping have shown that the aquifer can supply emergency water in a safe way without any apparent risk of seawater intrusion to the Al-Khod Aquifer. The results show that Muscat can be easily supplied by emergency groundwater for up to 10 consecutive days with volumes varying between 24 and 71 l/cap/day at a low cost of US$0.18 per m 3 . Covering up to 66% of the total regular demand during an emergency is technically feasible but would bring the cost up to US$1.49 per m 3 for groundwater and a cost of US$38.6 per m 3 for storage reservoirs made of concrete. The cost per m 3 of using concrete reservoirs is close to the market price of bottled water. Finally, the Public Authority for Electricity and Water might think of decentralizing the water storage at house levels by requiring new houses to be equipped with reservoirs on the roofs.
Younger groundwater found in some Omani aquifers is a result of recent recharge from cyclonic and... more Younger groundwater found in some Omani aquifers is a result of recent recharge from cyclonic and storm events [Weyhenmeyer et al. (Science 287:842-845, 2000); Young et al. (J Appl Geophys 57:43-61, 2004)]. The analysis of the meteorological data in Oman indicates an anomalous rainfall on a decadal interval whereas cyclones frequency is expected to increase due to global climatic changes. The cyclone Gonu has severely struck the eastern Omani coasts in 2007 resulting in devastating floods. Huge volume of water (3,672 mm 3 ) spread over the coastal plain calling for an assessment of potential groundwater recharge subsequent to this event. The present study evaluates groundwater recharge with respect to Gonu 2007 to assess the potential of recharge induced by such cyclones in the arid zones. The hydrographs of several piezometers sited along the coastal plain in Muscat Province have been studied and variation in water table rise has been analyzed. Significant water table rise is indicated for areas with geological and structural settings favoring rapid infiltration of water yielding considerable groundwater mound, whereas piezometers located in less favorable zones show minimum rise of water table. However, soon after the floods the aquifer hydrodynamics has readjusted to attain equilibrium and the groundwater mound dissipated. The cumulative rise of the water table on an areal extent does not exceed a few centimeters indicating lesser volume of recharge. Comparatively, recharge from frequent precipitation along favorable zones produces more significant recharge compared with cyclonic events where surface water residence time is shorter to allow for efficient infiltration.
ABSTRACT Assessment of recharge zones of strategic aquifers in Northern Oman calls for quantifica... more ABSTRACT Assessment of recharge zones of strategic aquifers in Northern Oman calls for quantification of groundwater hydraulics in alluvial fans with a subjacent bedrock of various geometry. Unlike standard analytical solutions to a 2-D unconfined flow over a tilted bedrock and a common Dupuit–Forchheimer approximation we derive novel analytical solutions for subjacent confining layer of a non-constant slope or a bedding inconformity. We use a genuine 2-D flow model, conformal mappings and inverse boundary-value problems methods. For flow over an arbitrary corner the vertex is either a stagnation point or point of infinite Darcian velocity. The hodograph domain (a circular triangle) is mapped onto a complex potential strip via an auxiliary half-plane. A non-planar aquifuge is also reconstructed as a streamline, along which an additional “control” boundary condition holds (pore pressure as a function of an auxiliary variable).
The present study applies Darcy's Law to compute evapotranspiration in the arid to semi-arid... more The present study applies Darcy's Law to compute evapotranspiration in the arid to semi-arid central Sudan. The average decline in groundwater level (s) along a distance (L) of the aquifer's cross section was calculated. Such decline is a function of discharge Q at any point across the unit width of the aquifer and effective porosity. Groundwater in the study area generally flows from NW to the SE along basin axial trough and is characterized by variable hydraulic gradient. As the aquifer discharge is directly proportional to the gradient, different values of groundwater level decline were calculated along the flow direction. The hydrogeological map constructed during this study indicates that the system is hydrologicaly closed and groundwater doesn't discharge in the neighboring White Nile River. Geological, hydrological and climatological settings of the discharge area demonstrate that evapotranspiration is the main mechanism of groundwater discharge and reveals tha...
Abstract The present study determines the source of dust particles and investigates their impact ... more Abstract The present study determines the source of dust particles and investigates their impact on the chemical compositions of plants and soils around a cement factory in Oman within a radius of 10 km of this disturbed ecosystem. A total number of nine samples of the species of ...
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