Map Viewing Service (WMS) of the dataset: Mapping of the alump removal of clays on the commune of Pompiac (Gers)

The mapping of the hay removal of clays in the municipality of Pompiac 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.

法国热尔省蓬皮阿克（Pompiac）市镇内黏土胀缩现象的绘图数据源自法国地质与矿业研究局（BRGM）编制的省级绘图成果。该绘图为黏土土壤胀缩现象发生概率的分区图。法国地质与矿业研究局（BRGM）首先基于纯物理准则，依托该省的地质图编制了易发性分区图，解译过程中针对每个地质单元考量了以下因素：
— 该单元内黏土物质占比（岩相分析）；
— 黏土组分中膨胀性矿物占比（矿物组成分析）；
— 该物质的岩土工程特性。
针对所识别的每个黏土地质单元，最终的灾害等级由前述得到的易发性等级，结合灾害性膨胀密度（以每100平方千米实际出露城市化地表为统计基准）共同确定。