基于圈层结构的绿洲生态安全问题研究

Study on the Oasis Ecological Safety Problem Based on the Ring Structure

干旱区生态圈层结构是在特定气候条件下水资源有效分配形成的,是生态系统稳定性和生态服务健康性的客观表达。荒漠化背景决定了各圈层类型发育的唯水(径流)性,水资源时空分布及其转化的竞争性决定了圈层结构的脆弱性,社会经济、生态环境耗水的满足程度及景观格局变化决定了圈层结构的生态安全状态。以流域水资源利用率不超过70%和生态耗水率不低于50%为标准,结合圈层结构变化所带来的生态问题分析,得出:干旱区内陆河流域生态系统组成、结构、功能存在重大缺陷,人类活动改变了水资源分配的有效性,生态耗水出现长期亏损,导致圈层结构完整性的基础——天然绿洲及过渡带趋于退化,生态安全问题难以有效遏制,已给干旱区生态经济发展带来了现实和潜在的威胁。

The ecological ring structure in arid area has formed through the effective assignment of water resources in the specific climatic conditions. It is the objective expression of the eco-system stability and ecology service healthy. The desert background decides its only water （runoff） dependence of various types of growth. The competition of the temporal and spatial distribution and transformation of the water resources decides the ring structure vulnerability. The satisfied degree of water consumption of social economy and eco-system and the landscape pattern change decides the ecological safety state of the ring structure. Taking water resources use ratio lower than 70% and the ecological water consumption rate upper than 50% in river basins as a standard, related the ecological problems due to ring structure changes is analyzed. The analysis incate that the composition, structure and function of ecosystem of inland river basins exist significant flaw because of the change of the ring structure. The human activity changes the effectiveness of water resource distribution. The ecological water consumption experiences a deficit for a long time. It causes the natural oasis, foundation of the complete ring structure and the intermediate belt tend to decline. The ecological safety problem can not be contained effectively. It has brought realistic and the potential threat for the ecological economy development in arid areas.