URBAN GEOLOGY - A CASE-STUDY OF TONGCHUAN CITY, SHAANXI PROVINCE, CHINA

Urban geology is the study of urban geologic environments to provide a scientific basis for rational land use planning and urban development . This paper examines the major geotechnical and environmental geologi c problems arising from the characteristics (topography, geology and s oil types, including their properties and areal distribution) and huma n engineering activities (slope excavation, underground mining) of Ton gchuan city. The main factors restricting urban development are: steep slopes; landslides; the wide distribution of problematic soils; flood ing; and surface subsidence caused by underground mining. Information theory has been applied to predict the slope susceptibility. The area of surface subsidence caused by mining at present and in the future is delimited using a finite element method. The factors closely related to land use planning are: slope susceptibility and landslides; floodin g; collapsible soils; surface subsidence related to mining; and the lo w bearing capacity of a bearing layer. These are combined to produce u niform engineering geological units. The result of a suitability asses sment of the study area is illustrated in the form of a rational land use planning map.