水沙过程变异下洞庭湖系统功能的连锁响应

Response of Dongting Lake's System Function Under Changed Water and Silt Process

从作用于洞庭湖系统功能的水沙过程入手,探讨水沙过程变异下湖泊系统功能的连锁响应认为:①洞庭湖是一个由其形态系统功能﹑生态系统功能和服务系统功能共同维系的巨系统;②水沙条件变化导致湖盆结构变形﹑湖面湖容缩小﹑生物多样性不稳定﹑航运里程缩短﹑水环境净化能力减弱﹑东方田鼠与钉螺极度膨胀﹑鱼类捕捞产量和水资源量减少等响应现象;③水沙过程变化与湖泊系统各项功能之间始终保持着短期与长期﹑局部和整体等不同层次﹑不同时空的耦合关系,因而表现出层次关联性﹑时空差异性﹑对应因果性和相互依存性等特性。

Response of Dongting lake system function was discussed under water and silt process change and the following viewpoints were derived.First of all,Dongting Lake is a macro-system composed of morphological system,ecological system and service system.Secondly,water and silt changes resulted in several responses phenomenon such as the deformation of lake basin framework,shrinkage of lake area and volumes,instability of biodiversity,shorter shipping mileage,decrescence of water environment purification capability,weakening of microtus fortis and Oncomelania,and decreasing in fishing output and water resource.Finally,there existed a coupling relationship between the change of water and silk process and various lake system functions at different levels and in different space（the whole and the parts） and time（short-term and long-term）.Some characteristics about hierarchy relevance,spatio-temporal difference,corresponding causality and mutual interdependency were shown.