人类最大可持续海洋足迹的模拟

The simulation of human maximum sustainable marine footprint

在William Rees & Mathis Wackernagel最初提出的生态足迹模型理论所划分的六类基本生态生产性土地面积中,海洋以其能为人类提供鱼类等海产品而被单独列为水域一项。海洋生物资源是一种典型的可再生资源,人类只有采取合理的开发策略方可保证海洋生物资源最大的可持续生产量。借用生态足迹、生物承载力概念的内涵,提出海洋足迹、海洋承载力两个新概念;运用非线性科学理论在海洋足迹与海洋承载力呈二次非线性关系的假设下,建立海洋承载力二次非线性开发的动力模式,并运用稳定性分析理论对其求解、分析。结果表明:(1)海洋承载力与其增长率呈正相关关系,与海洋足迹增长率呈负相关关系;(2)为保证海洋生物资源的可持续利用,人类必须控制最大海洋足迹增长率为r/xm(r为海洋承载力增长率,xm为最大海洋承载力),方可获得可持续的最大海洋足迹为rxm/4,此时海洋承载力可以维持在稳定的平衡态(为其最大承载力的一半)。

Oceans, from which people could gain marine biologic resources, are considered as one of six types of basic ecological productive land areas of Ecological Footprint Model proposed by William Rees ＆ Mathis Wackernagel. As a result, it is safe to draw a conclusion that marine biologic resources are very important. Because marine biologic resources are typical renewable resources, the maximum sustainable yield of marine biologic resources will be accessible if rational empolder strategy is adopted. Based on the conceptions of ecological footprint and biocapacity, we put forward new conceptions of marine footprint and marine biocapacity. According to their nonlinear dynamic relationship, a quadratic nonlinear dynamic model for marine footprint and marine biocapacity in this paper. Moreover, the value of the model is calculated and the results are analyzed in terms of the theory of stability analysis. The results show that ： （ 1 ） The marine biocapacity is positively correlated to its growth ratio and negatively correlated to marine footprint＇s growth. （2） For the sake of the sustainable empolder of the marine biologic resources, the maximum growth ratio of marine footprint should not be overrun r/xm （r refers to marine biocapacity growth ratio, and x refers to maximum marine biocapacity）. Only in this way,can the maximum sustainable marine footprint be equal to rmx/4, and the marine biocapacity will hold out steady equilibrium, the half of the maximum marine biocapacity.