Cloud-Model-Based Method for Risk Assessment of Mountain Torrent Disasters

Abstract

Mountain torrent disasters are common natural hazards that occur in mountainous terrains. The risk assessment of mountain torrent disasters entails a multi-criteria decision-making process and involves a transformation between qualitative and quantitative uncertainties. By incorporating probability statistics and fuzzy set theories, cloud model derived from information science, can aid the required transformation between the qualitative concepts and quantitative data. A cloud model-based approach has thus been proposed for practical risk assessment of mountain torrent disasters. The hybrid weighting method comprising the analytic hierarchy process (AHP) and entropy was employed for determining the weights of the indicators in the multi-criteria decision-making process. The degree of certainty associated with a particular risk level can be calculated through repeated assessments by employing the normal cloud model. The proposed approach was validated by comparing with the actual situation. The obtained results demonstrate that the cloud-model-based method is capable of indicating the risk level of mountain torrent disasters, as well as signifying the relative probability of risk at the same level. The proposed study provides guidelines for future risk management of basin floods and extends the scope of present risk-evaluation methods. Thus, the proposed study can be helpful in the precaution of mountain torrent hazards.

Risk assessment method of coal and gas outburst based on improved comprehensive weighting and cloud theory

“…A larger He value represents greater cloud dispersion, and the corresponding cloud will be thicker. To ensure that the uncertainty of entropy En of each assessment index is consistent, reduce the fuzziness and uncertainty at the boundary, and increase the reliability of the cloud model, He is typically set to 0.05 based on engineering cases (Guo et al, 2018;Li and Du, 2017;Yang et al, 2018). For the case where the assessment index has a unilateral boundary, such as Based on Equations ( 2) and ( 3), the risk assessment index system of coal and gas outbursts (shown in Figure 3), and the assessment grade standard (shown in Tables 1 and 2), the cloud numerical characteristics of coal and gas outburst assessment indexes were determined (as shown in Table 3).…”

“…The x conditional cloud generator based on the normal cloud model can generate the measured data x 0 of the coal and gas outburst risk assessment index U j (j = 1, 2, …, 9), which belongs to the membership degree μ ij of different risk grades i (i = 1, 2, …, 5), and form the membership matrix of the cloud model. Subsequently, it is combined with the membership matrix of the cloud model and the comprehensive weight ω j to determine the comprehensive membership degree U i (Yang et al, 2018), as follows:…”

A Novel Hybrid Approach for Water Resources Carrying Capacity Assessment by Integrating Fuzzy Comprehensive Evaluation and Analytical Hierarchy Process Methods with the Cloud Model

“…Assume the upper and lower boundaries of the evaluation level j of indicator i are x u i,j and x l i,j , then the expected value of the membership degree of the indicator i for the evaluation level j is [38]:…”

A Normal Cloud Model-Based Method for Risk Assessment of Water Inrush and Its Application in a Super-Long Tunnel Constructed by a Tunnel Boring Machine in the Arid Area of Northwest China

“…It can achieve a good conversion between a qualitative concept and its quantitative instantiations. So far, it has been widely applied in the stability classification of surrounding rocks, evaluation of water-use efficiency, prevention and control of disaster, and other areas [28][29][30].…”