基于冲击模型方法的自然保护区可靠性研究:以草海为例

Reliability of nature reserve based on shock Model method with an example of Caohai Lake

自然保护区是受特殊保护和管理的一类特殊的可靠性系统。本文从可靠性视角出发,利用冲击模型方法和MATLAB随机模拟技术,以贵州草海为例分析自然保护区系统的寿命行为和失效规律。分析结果表明:(1)20世纪50年代以前,草海系统受到的人为干预相对较少,可靠性长期保持相对稳定。以人类活动为主的冲击影响始于20世纪50年代末,对保护区生态功能产生了强烈干预。(2)在1958—1980期间,政府出于防涝减灾考虑的引流排水行为扮演了系统的主要冲击,对其可靠性产生了毁灭性影响。(3)在1980年之后的30多年里,周边农民出于造田增地需求的排水毁林自发性活动则形成草海保护区的新一轮冲击,并持续影响着系统的生态功能。(4)目前草海在调节气候、缓解灾害、保持生物多样性方面的生态功能已严重弱化。如果最近几十年的人为冲击模式不能得到有效缓解,保护区系统极有可能在近期内再次发生功能性崩溃。

Nature reserves are a special kind of reliability systems with the special protection and management policies. From the perspective of reliability theory, this paper attempts to investigate the life behavior and failure law of a nature reserve system by combined using shock model method and MRTLAB stochastic simulation and with a realistic example of Caohai Lake in Guizhou Province. According to our analytical results, it drew following conclusions：（1） until the 1950s, due to less human intervention, the system reliability of Caohai Nature Reserve remained relatively stable for a long time. The impacts of human activities began in the late 1950s, which caused a strong interference on the ecological function of Caohai Lake. （2） During the period of 1958 - 1980, the government behavior for preventing flooding and increasing farmland formed the main shocks on Caohai Nature Reserve and had a devastating impact on the system reliability. （3） For more than 30 years after 1980, the farmers spontaneous activity of growing farmland from draining off water and deforestation developed a new round of shock which caused a continuous effect on the ecological functions of the system. （4） The current ecological functions of Caohai Lake for regulating climate, relieving natural disasters and maintaining biological diversity severely weakened. If such an impact pattern could not be effectively alleviated, then a functional collapse of Caohai Lake system shall occur again with a high probability in the very near future.