Dataset Direct Download Service (WFS): Mapping of the alump removal of clays on the commune of Frégouville (Gers)

The mapping of the hay removal of clays in the commune of Frégouville in the Gers department is extracted from the departmental mapping from the BRGM. This mapping is a zoning of the probability of occurrence of the phenomenon of shrink-inflating of clay soils. A susceptibility map was first drawn up on the basis of purely physical criteria by the BRGM from the geological maps of the department, which were interpreted taking into account the following factors for each geological formation: — the proportion of clay material within the formation (lithic analysis); — the proportion of blowing minerals in the clay phase (mineralogical composition); — the geotechnical behavior of the material. For each of the clay formations identified, the hazard level is ultimately the result of the level of susceptibility thus obtained with the density of sinister swelling, reported to 100 km² of actual urbanised outcropping surface.本数据集提取自法国地质与矿业研究局（BRGM）编制的热尔省（Gers）部门级地理制图，内容为热尔省弗雷古维尔公社的黏土胀缩危害相关制图成果。该制图为黏土土壤收缩-膨胀现象发生概率的分区图。 法国地质与矿业研究局最初基于纯物理准则，依托该省地质图编制了敏感性分区图，编制过程中针对每个地质单元，综合考量以下三类因素： — 地层内黏土物质占比（岩相分析）； — 黏土相中的风成矿物占比（矿物组成）； — 岩土体的工程力学特性。 针对已识别的各黏土地层，最终的危害等级由上述敏感性等级结合灾害性胀缩发生密度（按每100平方千米实际出露城市化地表面积归一化折算）共同确定。