Eutrophication Hazard Evaluation Using Copula-Cloud

Abstract

A copula-cloud (C-C) coupled framework is proposed with respect to the uncertainty and multi-criteria mapping in water environmental hazard evaluation, with introducing copulas and cloud model theory. In the C-C framework, cloud models are firstly generated with given risk criteria which quantify the concept of risk from each dimension, before that copulas are estimated with the dependence of observed water quality data. The multi-dimensional copula-cloud model can be finally constructed with connecting all clouds by copulas, which can model the randomness, fuzziness and dependence of each risk criterion in assessment. The C-C technique have been applied on cases of representative lakes or reservoirs in China. Results in comparison with relevant proposed methods verify the completeness and effectiveness of the technique. As a beneficial exploration on clouds and copulas, the proposed C-C technique provide an innovative approach in relevant risk assessment.