Application of the catastrophe progression method in predicting coal and gas outburst

Based on catastrophe theory,we used the catastrophe progression method to predict the risk of coal and gas outbursts in coal mines.According to the major factors affecting coal and gas outbursts,we built a comprehensive evaluation index system and a coal and gas outburst prediction model.In addition,we performed a standard transformation for each index system;based on the degree the various indices affect the risk of an outburst,to make the data dimensionless.Based on the outburst data from eight mines,we determined catastrophe progression values and verified these values.The results show that:1) converting multi-dimensional problems into one-dimensional problems using this catastrophe progression method can simplify the steps of predicting coal and gas outbursts;2) when pre-determined catastrophe progression values are used to predict coal and gas outbursts,the predicting accuracy rate can be as high as 87.5%;3) the various coal mines have different factors inducing outbursts with varying importance of these factors and 4) the catastrophe progression values,calculated based on these factors,can be used effectively to predict the risk of outbursts in coal mines.

Urban Earthquake Vulnerability Assessment and Mapping at the Microscale Based on the Catastrophe Progression Method

Vulnerability assessment and mapping play a crucial role in disaster risk reduction and planning for adaptation to a future earthquake.Turkey is one of the most at-risk countries for earthquake disasters worldwide.Therefore,it is imperative to develop effective earthquake vulnerability assessment and mapping at practically relevant scales.In this study,a holistic earthquake vulnerability index that addresses the multidimensional nature of earthquake vulnerability was constructed.With the aim of representing the vulnerability as a continuum across space,buildings were set as the smallest unit of analysis.The study area is in İzmit City of Turkey,with the exposed human and structural elements falling inside the most hazardous zone of seismicity.The index was represented by the building vulnerability,socioeconomic vulnerability,and vulnerability of the built environment.To minimize the subjectivity and uncertainty that the vulnerability indices based on expert knowledge are suffering from,an extension of the catastrophe progression method for the objective weighing of indicators was proposed.Earthquake vulnerability index and components were mapped,a local spatial autocorrelation metric was employed where the hotspot maps demarcated the earthquake vulnerability,and the study quantitatively revealed an estimate of people at risk.With its objectivity and straightforward implementation,the method can aid decision support for disaster risk reduction and emergency management.