Research On A Comprehensive Evaluation Method For Seismic Hazard Of Urban Land

Urban Land Comprehensive Seismic Hazard Index (ULCSHI), which is firstly presented in this paper, analyses the earthquake disaster threats faced by a city from a different perspective (according to the functional-division of urban land). This comprehensive and hierarchical index system which focuses on the middle-spatial imbalance of the seismic hazard within a city can not only allow direct comparison of relative seismic hazard and give their spatial distribution features of different urban land within a city, but also describe the relative contributions of various factors(direct risk, collateral risk, hazard-bearing body, Landuse function, vulnerability and emergency evacuation and disaster relief ) to the overall hazard, from which the feature of hazard of each urban land could be given and then many correlative tasks such as urban disaster-reduction planning, resource allocation, city planning and management, land utilization and site choosing could be aided. ULCSHI is different from the existing hazard assessment approaches in three aspects. Firstly, taking urban land as the study unit according to the functional-division of urban land makes ULCSHI be evidently superior in many respects such as theoretical significance, practical significance, practicability and guidance to urban planning administration. Secondly, taking the comprehensive index form makes ULCSHI easy to understand and use. This can not only consider those disaster components which cannot be described through physical results in general hazard analysis methods, but also allow the nonprofessional users, e.g. city planner, make use of the index in their work. Thirdly, the hierarchical structure of ULCSHI provided the different users with needed information according to their requests and knowledge level about the earthquake disaster. Finally, the basis on which factors were identified is not the categories of hazard-bearing body, as other approaches do, but the effects of the factors on the disaster formation, which is advantageous in revealing the reason of hazard formation. Developing a city's ULCSHI should involve the following six-step procedure: (1) Determine the study unit of ULCSHI; (2) Create a conceptual framework of all the factors that contribute to ULCSHI; (3) Choose measurable indicators to represent each of factors in the framework; (4) Collect the data of indicators; (5) Determine the...