多模式发展的港口生态承载力演变

生态承载力是区域可持续发展的重要衡量标准,研究港口生态承载力状况并预测其演变趋势有利于港口生态可持续发展。针对现有港口生态承载力研究中生态过程机制、时间动态性考虑不足等问题,引入系统动力学理论,结合港口生态系统的特点,从社会经济、资源、环境3个方面进行因果反馈分析,在此基础上构建港口生态承载力的系统动力学模型。从港口生态供需关系的角度出发,引入生态承载力供需平衡指数,对港口生态承载力状况进行评价。以大连某港区为例,以GDP增长率、环保投资比重、单位吞吐量综合能耗、单位吞吐量水资源消耗量、单位吞吐量COD产生量、单位吞吐量SO_2产生量、单位吞吐量固废产生量作为调控变量,动态仿真自然发展模式、经济快速增长模式、协调发展模式和资源环境保护模式4种港口发展模式下2015—2030年港口生态承载力演变趋势。结果表明:能源消耗是制约该港区生态承载力改善的重要瓶颈,优化港口用能结构、加强港口能源管理有助于改善港口生态承载力;经济资源环境协调发展模式是实现港口生态系统可持续发展的最优模式。

On the evolutionary trend of the port with ecological bearing capability of the multiple-functional development modes

The present paper is inclined to bring about its study on the evolutionary trend of the port with ecological bearing capacity of the multiple-functional development modes.For the said purpose,the paper has introduced first of all the system dynamics theory for developing such ports based on the causative loop analysis approach from the point of view of the social economy,human and material resources and the environment-development trends,for such a theory is essentially beneficial for the sustainable development of port ecosystem.In view of the insufficient account of the ecological process and the temporal dynamic features in the current research on the port ecological bearing capacity,we have paid special emphasis on the study of the characteristic features of the port ecosystem,in hoping to keep the ecological supply-demand balance of such ports,we have brought about the supply-demand balance indexes of the ecological bearing capacity in evaluating the ecological bearing capacity in hoping to provide well-investigated and well founded theoretical and applicable facts and proofs.In a case study of a port area of Dalian Port,we have simulated the evolutionary trend of such port ecological bearing capacity from 2015 to 2030 dynamically under the four developmental modes,that is,the natural development mode,the fast economic growth mode,the coordinated development mode,and the resources and environment protection mode with the annual GDP growth rate in addition to the environmental protection investment proportion,the comprehensive energy consumption per throughput,the water consumption per throughput,the COD emission per throughput,SO2 emission per throughput and the solid wastes production per throughput as the control variables.The resuhs of our simulated study indicate that the key bottleneck restraints for improving the aforementioned ecological bearing capacity is the energy consumption.It is just the energy consumption sum-total and the consumption mode that account for the chief factors that are responsible for the port ecological bearing capacity.And,in turn,the best way to achieve the goal of sustainable ecological development of the port is to realize the coordinated development in economy,resources and eco-environment,which can be taken as a theoretical foundation for the future construction of Dalian Port.