论喀斯特环境的脆弱性

ON THE FRAGILITY OF KARST ENVIRONMENT

占全球陆地面积15%,居住着近10亿人口的喀斯特区域,是一个特殊的自然环境。在环境科学和喀斯特学间的互相渗透和交叉,产生了喀斯特环境学这一边缘分支学科。本文从系统论的观点、人地关系角度简要地论述了喀斯特环境的结构、功能和特性,并以贵州为例,对喀斯特环境脆弱性问题进行了分析,笔者认为:环境生态系统变异敏感度高,环境容量低,灾变承受阈值弹性小,是喀斯特环境脆弱性的最本质特征。

Karst environment is a specific natural environment.Structurally,it consists of both surface and subsurface spatial systems which are closely interrelated.Matter and energy in all three phases(solid,liquid,gas),organic and inorganic,life and non-life of the cal- cium-rich lithosphere,hydrosphere,atmosphere and human-biosphere interchange vigorously through the three-dimensional boundary surface of the karst system and be- come dynamical-equilibriumed.Therefore the karst environmental system with the activ- ities of the matter and energy is a large complicated open system.under the adjustment and control of a set of factors,the karst environment has experienced the processes of evolution,equilibrium and variation.Guizhou province,the biggest karst area of China with its well-known plateau-gorge landscape is mainly a typical fragile karst environ- ment.It is a“naturally rich but economically poor”plateau or mountainous region.The author takes Guizhou karst as an example to discuss the fragility of karst environment and describes that it is with 3 basic characteristics,the high sensibility of the ecosystem variation,the low environmental capacity and threshold of elasticity to endure catastro- phes.