Dataset Direct Download Service (WFS): N_ZONE_ALEA_PPRN_20140400_S_032

The mapping of the hay removal of clays in the commune of Arblade-le-Bas 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.本数据集所涵盖的热尔省阿尔布拉德勒巴（Arblade-le-Bas）市镇内黏土中夹杂干草移除作业的测绘图，提取自法国地质与矿业研究局（BRGM）的省级测绘成果。该测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）首先基于纯物理判据，依托该省地质图编制了易发性分区图，编制过程中针对各地质构造，综合考量了以下因素： — 地层内黏土物质的占比（岩性分析）； — 黏土相中易风蚀矿物的占比（矿物组成）； — 岩土体的工程性状。 针对每一处已识别的黏土地层，最终的灾害等级由上述方法得到的易发性等级，结合每100平方千米实际出露城市化地表的灾害性胀缩发生密度综合确定。