Groundwater bodies — Martinique — State of Places version 2019

A groundwater body is a separate volume of groundwater within one or more aquifers, constituting the elemental division of aquatic environments intended to be the WFD assessment unit. Groundwater bodies are derived from work carried out on the BDLISA repository. The splitting used for water bodies meets the following main principles: — Water bodies are delimited on the basis of geological and hydrogeological criteria; — The redivision of water bodies to take account of the effects of anthropogenic pressures must remain limited; — The limits of water bodies must be stable and durable; — Similar to surface water bodies, the delimitation of groundwater bodies is organised from a typology. This typology is largely inspired by that developed for hydrogeological entities defined in the framework of the revision of BDLISA. It is based on the geological nature and hydrodynamic behavior or “big” operation of aquifer systems (nature, flow velocity). It comprises 2 levels of characteristics (main and secondary); — Bodies of water may have exchanges between them; — All water withdrawals for drinking water supplying more than 10 m³/day 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, in which no sampling takes place and which are not likely to be used for drinking water because of their quality (salinity, temperature, etc.), or for technical and economic reasons (disproportionate cost of abstraction) may not constitute bodies of water; — 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 state; — At any point several bodies of water may overlap. (source: according to BRGM, DCE IMPLEMENTATION: Identification AND DELIMITATION OF SOUTERRAINE WATER MASSES — Methodological Guide, January 2003) Correspondence report DCE: this entity corresponds to WISE’s Ground Water Body (GWB) concept. The layers are distributed in a format consistent with the SANDRE data dictionary of the Water Mass Reference, version 1.4.地下水体（groundwater body）是指单个或多个含水层（aquifer）内的独立地下水块，属于水生环境的基础划分单元，同时为欧盟水框架指令（Water Framework Directive, WFD）指定的评估单元。 此类地下水体的数据源自BDLISA数据库（BDLISA Repository）。 地下水体的划分需遵循以下核心原则： — 水体应依据地质与水文地质标准进行划定； — 为应对人为压力影响而开展的水体重新划分工作应严格受限； — 水体边界需具备稳定性与持久性； — 与地表水体类似，地下水体的划定需基于类型学体系。该类型学体系主要借鉴了BDLISA修订框架内定义的水文地质实体分类方法，以含水层系统的地质属性、水动力特征或“宏观”运行特性（如介质性质、水流速度）为划分依据，包含两级特征参数（主特征与次特征）； — 不同水体之间可存在水力联系； — 所有日取水量超过10立方米，或用于供应50人以上饮用水的取水行为，均需纳入对应水体的管理范畴； — 与河流及地表生态系统无关联的深层地下水，若未开展采样工作，且因水质问题（如盐度、温度等）或技术经济原因（取水成本过高）不适合作为饮用水源，则可不划定为地下水体； — 鉴于自身规模特性，单一天然水体可能在水文地质特征、水质与水量状态上存在一定空间异质性； — 同一区域可存在多个重叠分布的水体。 （数据来源：法国地质与矿产研究局（BRGM），《欧盟水框架指令实施：地下水体的识别与划定方法学指南》，2003年1月） 欧盟环境与气候总局（DCE）对应报告表明：该实体与WISE的地下水体（Ground Water Body, GWB）概念完全匹配。 本次数据集的图层采用符合《水体参考数据字典（SANDRE Data Dictionary）》1.4版的标准格式进行组织与发布。