Map of the haea removal swelling of clays on the commune of Fleurance (Gers)

The mapping of the hay removal of clays in the commune of Fleurance in the department of Gers 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热尔省弗莱朗斯市镇内的黏土收缩-膨胀现象区划图，该图源自法国地质矿产调查局（BRGM）编制的省级地质区划成果。该区划图为黏土收缩-膨胀现象发生概率的分区图。法国地质矿产调查局（BRGM）首先基于纯物理准则，依托该省地质图编制了敏感性图，编制过程中针对每个地质单元，综合考量以下因素：
— 地质单元内黏土物质的占比（岩性分析）；
— 黏土相中膨胀性矿物的占比（矿物组成分析）；
— 该物质的岩土工程特性。
针对每一个已识别的黏土地质单元，最终的灾害等级由前述得到的敏感性等级结合灾害性胀缩发生密度（以每100平方千米出露已城市化地表为基准）计算得出。