Elementary polygons of groundwater bodies - Réunion - State of the Places Version 2013

Description

A body of groundwater is a separate volume of groundwater within one or more aquifers, constituting the basic delineation of aquatic environments intended to be the unit of assessment for the WFD. It makes it possible to define environmental objectives, to assess the state of the environment and subsequently to verify the achievement of these objectives. Groundwater bodies, based on the work carried out on the BDRHF V1 hydrogeological repository, were identified and delineated for the first time in 2004 and were updated in 2010. They were the subject of a report to the European Commission on the implementation of the WFD on 22 March 2010, followed by a corrective report in February 2011, taking into account the latest updates. At the beginning of 2013, work was carried out to bring the European version of February 2011 into line with the Sandre format. This version is still published on the SANDRE website; however, it contains a number of anomalies, present in the reported data, and highlighted in report BRGM/RP-62141-EN. These anomalies have been corrected in this version of the Water mass reference system: The "internal 2013 water body repository" in its version results from the update of the State of Places, in accordance with the Sandre data models and consolidated at the national level, on the website www.sandre.eaufrance.fr. This version of the reference system comes from the State of Places 2013 and is not reported to the European Commission. This version used at national level makes it possible to prepare the SDAGE 2016-2021. Layers shall be disseminated in a format compliant with the SANDRE Data Dictionary of the Water Body Repository, version 1.2. The water bodies are divided according to the following main principles: Water bodies shall be demarcated on the basis of geological and hydrogeological criteria. Redistribution of water bodies to take account of the effects of anthropogenic pressures must remain limited. Boundaries of water bodies must be stable and sustainable Like bodies of surface water, the delimitation of bodies of groundwater is organised on the basis of a typology. This typology is largely inspired by the one developed for hydrogeological entities defined in the context of the revision of the HFR DB. It is based on the geological nature and hydrodynamic behavior or "large" operation of aquifer systems (nature, flow velocity). It includes two levels of characteristics, primary and secondary. Water bodies can trade with each other. All abstractions for drinking water supply, supplying more than 10 m3/day of drinking water or used for the supply of water to more than 50 persons, must be included in a body of water. Deep groundwater, unrelated to rivers and surface ecosystems, from which no abstraction takes place and which is not likely to be used for drinking water because of its quality (salinity, temperature, etc.), or for technical and economic reasons (disproportionate cost of abstraction) may not constitute water bodies. Given its size, a body of water may have a certain spatial heterogeneity in terms of both its hydrogeological characteristics and its qualitative and quantitative status. At any point several water bodies may overlap. The PolygMasseDEauSouterraine layer results from the agglomeration into a single file of all groundwater bodies divided into elementary multipolygons corresponding to each of their depth levels. The entire national territory is covered, the polygons overlap. In other words, if one seeks to identify the water bodies present at a point in the territory, this layer can render 1 to 10 water bodies differentiated only by the associated superposition order. Compliant with the SANDRE V1.2 data dictionary, the layer is composed of the same attributes as the MasseDEauSouterraine layer with: - The addition of the ‘Level’ field: Depth level of the elemental multipolygon of the groundwater body; - The addition of the field ‘CdPolygMasseDEauSouterraine’: Unique code of the elemental multipolygon of the groundwater body.

Resources

Name Format Description Link
0 http://services.sandre.eaufrance.fr/geo/mdo_VEDL2013?Request=GetCapabilities&SERVICE=WFS&VERSION=1.1.0
0 http://services.sandre.eaufrance.fr/geo/mdo_VEDL2013?SERVICE=WFS&VERSION=1.1.0&REQUEST=GetFeature&typename=PolygMasseDEauSouterraine_REU&SRSNAME=EPSG:2975&OUTPUTFORMAT=SHAPEZIP
0 http://services.sandre.eaufrance.fr/telechargement/geo/MDO/MasseDEau/EtatDesLieux2013/REU/PolygMasseDEauSouterraine_VEDL2013_REU-mif.zip

Tags

  • france
  • données-ouvertes
  • hydrogeologie
  • eau-souterraine
  • reunion
  • hvd

Topics

  • TECH

Categories