Correlation Coefficient Matrix of Natural Environment Control Variable.

<p>Correlation Coefficient Matrix of Natural Environment Control Variable.</p

Scattergram of Mutation Situation of Navigational Environment in Three Gorges Reservoir Area.

<p>1, Yichang; 2, Guizhou; 3, Badong; 4, Wushan; 5, Fengjie; 6, Yunyang; 7, Wanzhou; 8, Zhongxian; 9, Fengdu; 10, Fuling; 11, Changshou; 12, Chongqing; 13, Jiangjin.</p

Use of Cusp Catastrophe for Risk Analysis of Navigational Environment: A Case Study of Three Gorges Reservoir Area

<div><p>A water traffic system is a huge, nonlinear, complex system, and its stability is affected by various factors. Water traffic accidents can be considered to be a kind of mutation of a water traffic system caused by the coupling of multiple navigational environment factors. In this study, the catastrophe theory, principal component analysis (PCA), and multivariate statistics are integrated to establish a situation recognition model for a navigational environment with the aim of performing a quantitative analysis of the situation of this environment via the extraction and classification of its key influencing factors; in this model, the natural environment and traffic environment are considered to be two control variables. The Three Gorges Reservoir area of the Yangtze River is considered as an example, and six critical factors, i.e., the visibility, wind, current velocity, route intersection, channel dimension, and traffic flow, are classified into two principal components: the natural environment and traffic environment. These two components are assumed to have the greatest influence on the navigation risk. Then, the cusp catastrophe model is employed to identify the safety situation of the regional navigational environment in the Three Gorges Reservoir area. The simulation results indicate that the situation of the navigational environment of this area is gradually worsening from downstream to upstream.</p></div

Framework for Evaluation of Navigation Risk.

<p>Framework for Evaluation of Navigation Risk.</p

Collection of Quantized Data.

<p>Collection of Quantized Data.</p

Collection of Original Metrical Data.

<p>Collection of Original Metrical Data.</p

Zoning Map of Navigational Environment in Three Gorges Reservoir Area Prepared from Results of Catastrophe Evaluation.

<p>The figure is similar but not identical to the original one, and is shown for illustrative purpose only.</p

Channel Mileage Statistics of Data Collection Sites in Three Gorges Reservoir Area.

<p>Channel Mileage Statistics of Data Collection Sites in Three Gorges Reservoir Area.</p

Cusp Mutation Area of Navigational Environment.

<p>Cusp Mutation Area of Navigational Environment.</p

Evolution Model of Navigation Risk with Variation of Navigational Environment.

<p><i>S</i> is the balance surface and <i>C</i> is the <i>M-N</i> control surface.</p