Simple download service (Atom) of the dataset: Mapping of the alump removal of clays on the commune of Polastron (Gers)

The mapping of the hay removal of clays in the commune of Polastron 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.本次数据集为热尔省波拉斯通公社内胀缩性黏土相关制图成果，其数据源自法国地质矿产调查局（BRGM）编制的该省官方地质图。该成果为胀缩性黏土土壤现象发生概率的分区图。法国地质矿产调查局（BRGM）首先依托该省地质图，基于纯物理准则编制了易发性制图，编制过程中针对每个地质单元，综合考量了以下因素： — 地层内黏土物质占比（岩性分析）； — 黏土组分中膨胀性矿物占比（矿物组成）； — 岩土体的工程特性。 针对每一个已识别的黏土地质单元，最终的灾害等级由上述易发性等级结合灾害性胀缩发生密度确定，统计基准为每100平方千米实际出露的城市化地表。