The hydrogeological entity is a part of the geological space, aquifer or non-aquifer, corresponding to a physical system characterised by its state and hydrogeological characteristics.
The hydrogeological entity must be understood in a systemic sense and corresponds to a breakdown of the geological space realised at a given stage of knowledge in particular for deep systems.
The constitution of hydrogeological entities is derived from knowledge at a given date of the underground environment (geological map, geological cutting, geological log, structural diagram and piezometric map).
Hydrogeological entities can be multi-part.
Hydrogeological entities cover the entire territory ensuring a horizontal and vertical relationship of entities in accordance with the principle of completeness.
A hydrogeological entity is a part of the geological space:
— delimited on a certain scale (level d' use)
— attached to a type of geological formation (theme)
— defined by its aquifer potentialities (nature)
— characterised by a type of porosity (mid)
— characterised by the presence or not of a tablecloth, which may be free, captive or free and captive (state)
They have been defined according to rules developed within the framework of a common national methodology and validated by a national steering committee under the responsibility of the Ministry responsible for the environment.
A hydrogeological entity will be represented by its orthogonal ground projection. The reference scale is the 1/50 000th, i.e. the national geological reference scale.
Each entity has a code that is assigned by the BRGM (Order of 26 July 2010, SNDE).
D' after Sandre, dictionary of the hydrogeological reference SAQ version 2.1
__Origin__
The entities disseminated are entities at local level (NV3). These entities have " parent entities; at the regional (NV2) and national (NV1) levels, these associations are described in the multi-scale table downloadable above.
__Partner organisations__
Ash, Bureau of Geological and Mining Research
__Links annexes__
* [see the interactive dictionary on Sandre website](http://www.sandre.eaufrance.fr/?urn=urn:sandre:dictionnaire:SAQ::entite:EntiteHydroGeol:ressource:2.1:::html)
* [see BDLISA’s delivery description v.2](http://www.sandre.eaufrance.fr/sites/default/files/document-sandre/Descriptif_données_BDLISA2_v3.pdf)
* [consult the monitoring report of hydrogeological entities online](http://mdm.sandre.eaufrance.fr/geo/rapports/public/EntiteHydroGeol)
* [recover an anomaly or propose a correction on the BDLISA forge](https://forge.eaufrance.fr/BDLISA)
* [download Level 3 Hydrogeological Entities — Guadeloupe BDLISA v.2 — Geodatabase Format](http://services.sandre.eaufrance.fr/telechargement/geo/SAQ/BDLISA/2/GLP/BDLISA_V2_GLP-gdb.zip)
* [download Level 3 Hydrogeological Entities — Guadeloupe BDLISA v.2 — SQLite Format](http://services.sandre.eaufrance.fr/telechargement/geo/SAQ/BDLISA/2/GLP/BDLISA_V2_GLP-sqlite.zip)
[See this page on geo.data.gouv.fr](https://geo.data.gouv.fr/fr/datasets/de4bcdedebbbd45d1769ebca5efcf9966e7c4afd)
Build on reliable and scalable technology
FAQ
Frequently Asked Questions
Some basic informations about API Store ®.
Operation and development of APIs are currently fully funded by company Apitalks and its usage is for free.
Yes, you can.
All important information such as time of last update, license and other information are in response of each API call.
In case of major update that would not be compatible with previous version of API, we keep for 30 days both versions so you will have enough time to transfer to new version. We will inform you about the changes in advance by e-mail.