Dataset Direct Download Service (WFS): Map of the alump removal of clays on the commune of Lourties-Monbrun (Gers)

The mapping of the alump removal of clays on the commune of Lourties-Monbrun in the Gers department is extracted from the departmental mapping derived 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产研究局（BRGM）编制的省级制图成果，其内容为热尔省（Gers）卢尔蒂-蒙布朗（Lourties-Monbrun）市镇范围内的黏土团块清除相关制图。该制图为黏土胀缩现象发生概率的分区图。法国地质与矿产研究局（BRGM）首先以纯物理判据为基础，依托该省地质图并结合针对各地质地层的以下要素，编制了易发性分区图：
— 地层内黏土物质的占比（岩相分析）；
— 黏土相中膨胀矿物的占比（矿物组成）；
— 岩土体的土工特性。
针对已识别的各黏土地层，最终的灾害等级为上述易发性等级与胀缩灾害密度的综合结果，该密度以每100平方千米实际出露的城市化地表为统计基准。