成都市地气地球化学初探——以土壤氡为例

城市地下库中的气体元素（如氧）能透过地面迁移、扩散到地上环境中，不同的地表覆盖材料会有不同的透气性。整个城市地层可以看作是零星分布着“软盖层”网孔的一个大“硬盖层”，表面大多覆盖着如水泥混凝土、地砖、沥青等硬质材料。以成都市土壤氡研究为例，证明在那些网孔和硬覆盖层边缘往往出现地气异常现象。因此，城市地气地球化学引出了新的研究思路，对城市建设和环境评价具有指导性意义。

Preliminary Probe to Geogas Geochemistry in Chengdu——Take the Concentration of Radon in Soils as A Case Study

Gaseous elements in urban underground can transfer or spread to the surface of the ground, and different surface has different capability of ventilation due to its covering material.The whole city surface layer can be taken as a piece of big hard cover where soft cover-layer meshes scatter sporadically.The surface of city is mostly covered with concrete, asphalt and so on.Taking the concentration of radon in soils of Chengdu as a case study,on the margins of those meshes and hard cover-layer,there often occur abnormal underground gas phenomena.So,gas geochemistry of city puts forward some new topics of scientific research, which play a guiding role in urban construction and environmental assessment.