2013年美赛ICM国际一等奖.pdf

The dynamic global network model for ecological footprint Summary The Earth’s environmental and biological systems are under greater pres- sure. This report is devoted to establish a global network model to analyze and evaluate the health condition of Earth. We apply the ecological footprint(EF) to describe the health condition- s of Earth firstly. A global network is established, in which the nodes are six geography regions divided according to geographic and economic fac- tors. There are three direct influencing factors, that is, population, Gross Domestic Product(GDP), and consumption level. They affect the ecological footprint. And other indirect influencing factors are also considered. Then resource flowing, cross regional trade, species migration, and international policy characterize the link properties. In addition, feedback mechanism is introduced to the network including self-adjustment of ecosystem, global strategic planning, related policies, etc. Then, we introduce the Health Index(HI) to evaluate the health condi- tion of the ecosystem. And a dynamic global network model for ecological footprint is developed. Using the multiple linear regression analysis, this report analyzes the relation between HI and every node’s EF and estab- lishes a formula. And the critical nodes appear: Asian-Pacific and Europe. Afterwards, with the help of Grey model(1, 1), we acquire the predictive values of three direct influencing factors. Then, the predictive values of EF and HI are obtained in sequence using multiple linear regression predic- tion. We generate a good prediction and find the tipping point occurs in the year 2058 when HI is 0. In addition, we alter the values of any node’s EF to observe the changing rate of HI of the ecosystem. And the conclu- sion is acquired: Region Asian-Pacific and Europe