Simple download service (Atom) of the dataset: N_ZONE_ALEA_PPRN_20140337_S_032

The mapping of the alump removal of clays on the commune of Lectoure 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.本数据集所涉及的热尔省（Gers department）莱克图尔公社（commune of Lectoure）范围内黏土块体移除（alump removal）的制图成果，数据源自法国地质矿产调查局（BRGM）的省级测绘成果。该制图成果为黏土土壤胀缩现象发生概率的分区图。 此前，法国地质矿产调查局（BRGM）依托该省地质图，以纯物理判定准则率先编制了胀缩敏感性分区图，制图过程中针对各地质单元综合考量了以下因素： — 地质单元内黏土物质的占比（岩相分析结果）； — 黏土相中膨胀性矿物的占比（矿物组成特征）； — 岩土材料的工程地质性状。 针对已识别的全部黏土单元，最终的危险等级由前述敏感性等级，结合以每100平方公里实际出露城市化地表为统计基准的胀缩灾害密度共同计算得出。