For a long time, the supply of drinking water to the island of Mar was ensured by drilling and wells. The advance of the salt wedge led the populations to stop the exploitation of the drilling due to the accentuation ...For a long time, the supply of drinking water to the island of Mar was ensured by drilling and wells. The advance of the salt wedge led the populations to stop the exploitation of the drilling due to the accentuation of the salinity of the water characterized by high fluorine content. The marine environment and the rainfall deficit of recent decades as well as population growth have highlighted the sensitivity of this resource. The objective of this article is to study the drinkability of the water supplied by the drilling and the wells of the island of Mar. for this, water samples were taken in the Continental Terminal and their analysis made in situ or in the laboratory. Data processing was done by using Surfer 11 and ArcGIS software. It was emerged from this study that the drop in the piezometric level caused an entry of salt water. The mineralization of the water follows a decreasing trend from areas with marine influence inland. Groundwater in certain areas is generally of good quality with some sources of pollution linked to salinity but also to high levels of nitrate, chloride and fluorine. The island of Mar being confronted with a problem of drinkability of groundwater, the alternative would be to proceed to a transfer of better quality water from nearby areas after a hydrogeological and physico-chemical study of these waters in relation to their fitness for consumption.展开更多
The tide induced groundwater fluctuation and the seawater intrusion have important effects on hydrogeology and ecology of coastal aquifers.Among previous studies,there were few quantitative evaluations of the joint ef...The tide induced groundwater fluctuation and the seawater intrusion have important effects on hydrogeology and ecology of coastal aquifers.Among previous studies,there were few quantitative evaluations of the joint effects of the beach slope and the tide fluctuation on the groundwater dynamics.In this article,a numerical model is built by using the software FEFLOW with consideration of seawater intrusion,tide effects,density dependent flow and beach sloping effects.The simulation results are validated by laboratory experimental data in literature.More numerical scenarios are designed in a practical scale with different beach slopes.Results show that the groundwater fluctuation decays exponentially with the distance to the beach,i.e.,,and our simulation further shows that the beach slope influence can be expressed in the form of a logarithm function.While for the same location,the amplitude increases logarithmically with the beach angle in the form,where and are related with the horizontal distance（）in the form of a logarithm function.The beach slope has no influence on the phase lag,although the latter increases regularly with the distance from the sea.The beach slope effect on the seawater intrusion is investigated through the quantitative relationship among the relative intrusion length（）,the relative enhancement of the tide induced seawater intrusion（）and the beach angle（）.It is shown that the tide effects on a milder beach is much greater than on a vertical one,and both λ and κ can be expressed in logarithm functions of.The tidal effect on the flow field in the transition zone for a particular mild beach is also studied,with results showing that the tide induced fluctuation of is similar to the groundwater table fluctuation while shows a distinct variation along both directions.展开更多
文摘For a long time, the supply of drinking water to the island of Mar was ensured by drilling and wells. The advance of the salt wedge led the populations to stop the exploitation of the drilling due to the accentuation of the salinity of the water characterized by high fluorine content. The marine environment and the rainfall deficit of recent decades as well as population growth have highlighted the sensitivity of this resource. The objective of this article is to study the drinkability of the water supplied by the drilling and the wells of the island of Mar. for this, water samples were taken in the Continental Terminal and their analysis made in situ or in the laboratory. Data processing was done by using Surfer 11 and ArcGIS software. It was emerged from this study that the drop in the piezometric level caused an entry of salt water. The mineralization of the water follows a decreasing trend from areas with marine influence inland. Groundwater in certain areas is generally of good quality with some sources of pollution linked to salinity but also to high levels of nitrate, chloride and fluorine. The island of Mar being confronted with a problem of drinkability of groundwater, the alternative would be to proceed to a transfer of better quality water from nearby areas after a hydrogeological and physico-chemical study of these waters in relation to their fitness for consumption.
基金supported by the Program for New Century Excellent Talents in Universities(Grant No.07-0814)
文摘The tide induced groundwater fluctuation and the seawater intrusion have important effects on hydrogeology and ecology of coastal aquifers.Among previous studies,there were few quantitative evaluations of the joint effects of the beach slope and the tide fluctuation on the groundwater dynamics.In this article,a numerical model is built by using the software FEFLOW with consideration of seawater intrusion,tide effects,density dependent flow and beach sloping effects.The simulation results are validated by laboratory experimental data in literature.More numerical scenarios are designed in a practical scale with different beach slopes.Results show that the groundwater fluctuation decays exponentially with the distance to the beach,i.e.,,and our simulation further shows that the beach slope influence can be expressed in the form of a logarithm function.While for the same location,the amplitude increases logarithmically with the beach angle in the form,where and are related with the horizontal distance（）in the form of a logarithm function.The beach slope has no influence on the phase lag,although the latter increases regularly with the distance from the sea.The beach slope effect on the seawater intrusion is investigated through the quantitative relationship among the relative intrusion length（）,the relative enhancement of the tide induced seawater intrusion（）and the beach angle（）.It is shown that the tide effects on a milder beach is much greater than on a vertical one,and both λ and κ can be expressed in logarithm functions of.The tidal effect on the flow field in the transition zone for a particular mild beach is also studied,with results showing that the tide induced fluctuation of is similar to the groundwater table fluctuation while shows a distinct variation along both directions.
