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Two areas of freshwater with low mineral content are found in Abu Dhabi Emirate<\/SPAN>:<\/SPAN><\/P>

In the northeast, rainfall from the Hajjar Mountains recharges the aquifer and slowly flows towards the Arabian Gulf. The longer the water remains in the aquifer, the more time it has to dissolve minerals and interact with the rocks: In general, the water gets more saline as it flows towards the sea. <\/SPAN><\/P>

Another area of low salinity is found north of Liwa, where recharge from rainfall is minimal and the resulting groundwater is older. Most of it entered the aquifer thousands of years ago, in a time with a more humid climate. Very slow groundwater flow, uniform sandy lithology, and a distinct vertical salinity gradient in the aquifer have kept the uppermost groundwater fresh for centuries. <\/SPAN><\/P>

Along the coast in the west, as well as in the southeast, the groundwater table is very shallow. In these sabkha flats, the groundwater comes close to the surface and some of it evaporates. The dissolved minerals stay behind and lead to a further salinisation of the groundwater. Water in these regions can be as salty as 140,000 mg/<\/SPAN>L<\/SPAN>; that is more than three times as salty as the water of the Arabian Gulf.<\/SPAN><\/P>

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Field Descriptions:<\/SPAN><\/P>

-OBJECTID<\/SPAN>:A<\/SPAN>unique, not null integer field used to uniquely identify rows in tables in a geodatabase.<\/SPAN><\/P>

-S<\/SPAN>hape:<\/SPAN>Field which shows the stored geometry type created through ArcGIS (Point, Line, Polygon, Multipoint or Multipatch)<\/SPAN><\/P>

-<\/SPAN>Classes:<\/SPAN>Consecutively numbered classes of Salinity (0-7)<\/SPAN><\/P>

-<\/SPAN>Value_Max:<\/SPAN>Upper value of TDS [mg/L] for the selected, corresponding salinity class<\/SPAN><\/P>

-<\/SPAN>Shape_Length:<\/SPAN>Represents the total length of a polygon's perimeter, in the units used by the feature class' coordinate system<\/SPAN><\/P>

-<\/SPAN>Shape_Area:<\/SPAN>Represents the total area of a polygon, in square units of the linear distance unit used by the feature class' coordinate system<\/SPAN><\/P>

-<\/SPAN>RuleID:<\/SPAN>Range of salinity class in mg/L for labeling purposes<\/SPAN><\/P>

-<\/SPAN>Override:<\/SPAN>A BLOB field that stores feature-specific override to the representation rules<\/SPAN><\/P>

Processing Steps: Geospatial TDS data from groundwater sampling has been interpolated using Kriging to create polygons showing the distribution of groundwater salinity in <\/SPAN>eight <\/SPAN>classes ranging from 0 to 50,000 mg/L<\/SPAN><\/P>

Resolution: n/a<\/SPAN><\/SPAN><\/P>

Data Quality: data was QC checked for consistency || توجد منطقتان من المياه العذبة ذات محتوى معدني منخفض في إمارة أبوظبي:<\/SPAN><\/P>

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في الشمال الشرقي، تُغذي مياه الأمطار من جبال الحجر الخزان الجوفي وتتدفق ببطء نحو الخليج العربي. كلما بقيت المياه في الخزان لفترة أطول، زادت فرصتها في إذابة المعادن والتفاعل مع الصخور: بشكل عام، تصبح المياه أكثر ملوحة مع تدفقها نحو البحر.<\/SPAN><\/P>

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منطقة أخرى ذات ملوحة منخفضة تقع شمال ليوا، حيث يكون التغذية من مياه الأمطار قليلة جدًا، وبالتالي تكون المياه الجوفية الناتجة أقدم. دخلت معظم هذه المياه إلى الخزان الجوفي قبل آلاف السنين، في فترة ذات مناخ أكثر رطوبة. التدفق البطيء جدًا للمياه الجوفية، التركيب الرملي الموحد، والتدرج العمودي المميز للملوحة في الخزان الجوفي حافظ على عذوبة المياه الجوفية العلوية لعدة قرون.<\/SPAN><\/P>

<\/P>

على طول الساحل في الغرب، وكذلك في الجنوب الشرقي، يكون منسوب المياه الجوفية قريبًا جدًا من السطح. في هذه المناطق السبخية، تقترب المياه الجوفية من السطح ويتبخر بعضها. تبقى المعادن المذابة وتؤدي إلى زيادة ملوحة المياه الجوفية. يمكن أن تصل ملوحة المياه في هذه المناطق إلى 140,000 ملغم/لتر؛ أي أكثر من ثلاثة أضعاف ملوحة مياه الخليج العربي<\/SPAN><\/P><\/DIV><\/DIV><\/DIV>", "geometryType": "esriGeometryPolygon", "sourceSpatialReference": { "wkid": 4326, "latestWkid": 4326, "xyTolerance": 8.98315284119521E-9, "zTolerance": 0.001, "mTolerance": 0.001, "falseX": -400, "falseY": -400, "xyUnits": 9.999999999999999E8, "falseZ": 0, "zUnits": 1, "falseM": 0, "mUnits": 1 }, "copyrightText": "Source Agency: DCI (2018)\nCollection Agency: DCI (2016/17)\nMaintenance Agency: EAD\nCustodial Agency: EAD\nContact: EAD - Environment Information, Science & Outreach Management (EISOM)", "parentLayer": { "id": 116, "name": "Environmental" }, "subLayers": [], "minScale": 0, "maxScale": 0, "referenceScale": 0.0, "drawingInfo": { "renderer": { "type": "simple", "symbol": { "type": "esriSFS", "style": "esriSFSSolid", "color": [ 179, 220, 252, 255 ], "outline": { "type": "esriSLS", "style": "esriSLSSolid", "color": [ 110, 110, 110, 255 ], "width": 0.7 } } }, "scaleSymbols": true, "transparency": 0, "labelingInfo": null }, "defaultVisibility": true, "extent": { "xmin": 51.58273163200005, "ymin": 22.63162140000003, "xmax": 56.010128733000045, "ymax": 24.91124780000007, "spatialReference": { "wkid": 4326, "latestWkid": 4326, "xyTolerance": 8.98315284119521E-9, "zTolerance": 0.001, "mTolerance": 0.001, "falseX": -400, "falseY": -400, "xyUnits": 9.999999999999999E8, "falseZ": -100000, "zUnits": 10000, "falseM": -100000, "mUnits": 10000 } }, "hasAttachments": false, "htmlPopupType": "esriServerHTMLPopupTypeAsHTMLText", "displayField": "CH_FID", "typeIdField": null, "subtypeFieldName": null, "subtypeField": null, "defaultSubtypeCode": null, "fields": [ { "name": "OBJECTID", "type": "esriFieldTypeOID", "alias": "OBJECTID", "domain": null }, { "name": "CLASSES", "type": "esriFieldTypeInteger", "alias": "Classes", "domain": null }, { "name": "VALUE_MAX", "type": "esriFieldTypeDouble", "alias": "Value_Max", "domain": null }, { "name": "RULEID", "type": "esriFieldTypeInteger", "alias": "RULEID", "domain": { "type": "codedValue", "name": "WS4_GroundwaterSalinityEC_Rep_Rules", "description": "Representation rules", "codedValues": [ { "name": "< 500 Fresh (WHO Standard)", "code": 1 }, { "name": "500 - 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