A cloud model based approach for multi-hierarchy fuzzy comprehensive evaluation of reservoir-induced seismic risk
Zhang Qiu-we · Journal of Hydraulic Engineering · 2014
Reservoir-induced earthquake is one of the most important tasks in the geological analysis and environmental assessment of water conservancy project. Because of the uncertainties in the process of its preparation and occurrence,the reservoir-induced earthquake is considered as a fuzzy system in this paper. After systematical identification,an evaluation index system of reservoir-induced seismic risk,which is divided into such levels as remark layer,indicator layer,factor layer and status layer,is established. In the traditional fuzzy comprehensive evaluation,the importance scale and membership degree of indices are easily impacted by personal experience and subjective consciousness during the weights calculation and fuzzy mapping. By introducing the cloud model,we propose an improved approach for multi-hierarchy fuzzy comprehensive evaluation of reservoir-induced seismic risk so as to solve this problem. The corresponding cloud models of remark set,weight and membership degree of index,as well as the cloud model of evaluation result of reservoir-induced seismic risk are built respectively. With the three numeric characteristics of cloud model such as expectation value(Ex),entropy(En) and hyper entropy(He),the fuzziness,randomicity and discreteness in reservoir-induced earthquake are organically combined together,and the uncertain languages are naturally transformed into quantitative values. Finally,as a case study,the proposed method is applied to the seismic risk evaluation of the Three Gorges reservoir on the Yangtze River. It's concluded that the robustness and visualization of multi-hierarchy fuzzy comprehensive evaluation of reservoir induced earthquake risk based on the cloud model are highly increased.