基于证据理论的不透水表面扩张模拟及其生态效应研究

Simulation of Impervious Surface Expansion and Its Environmental Effects

对不透水表面扩张导致的生态环境问题的探讨。认为,不透水表面扩张是人类改变自然的一个最直接的行为方式,其直接改变地表结构导致区域下垫面结构发生变化,得出“人类活动→土地利用/覆被变化→流域生态系统结构改变和功能退化”链式驱动机制。在该链式驱动模式上,采用D-S（Dempster-Shafer）证据理模型分析了不透水表面扩张的驱动机制,量化人类活动对不透水表面扩张的影响程度,最终预测流域在人文环境驱动下的不透水表面扩张。结果表明：2002年、2009年、2018年的滇池不透水表面覆盖率分别为：7.95%,13.40%,25.95%。2002年滇池流域不透水表面覆盖率〈10%,即“生态环境脆弱期”,如果没有其他环境压力,其生态系统结构和功能具有可持续性;2009年滇池流域不透水表面覆盖率在（10～25%）之间,即“生态系统受影响期”,具有明显的生态系统结构和功能退化迹象;依照目前的驱动机制和发展模式,到2018年,其不透水表面覆盖率〉25%,即“生态功能退化期”,其将带来不可逆转的生态破坏,如生态系统结构高度不稳定,生物多样性少,生态功能退化等现象。因此,要对滇池流域不透水表面扩张进行合理地规划,统筹经济发展和生态环境保护,以避免其带来不可控制的生态系统破坏。

This study explored surface expansion was the most the environmental effects of impervious surface expansion, direct way to change natural environment. A drive chain land use and land cover change, then to ecosystem structure change and function degradal thinking that impervious from human activities to tion was found. Based on the drive chain, D - S evidence theory was adopted to simulate the expansion of Dianchi - Basion＇ s impervious surface. The results showed that the impervious surface coverage were 7.95% in 2002,13.40% in 2009, 25.95% in 2018, respectively. Sensitive area has 0 to 10% imperviousness and typically has good water quality, good habitat structure, and diverse biological communities if riparian zones are intact and other areas are absent. Impacted streams have 10 to 25% imperviousness and show clear signs of degradation and only fair in-stream biological diversity. Non-supporting area have 〉 25% impervious, a highly unstable channel and poor biological condition supporting only pollutant-tolerant fish and insects. Thus, It should be reasonable to plan urbanization formation of Dianchi,giving consideration to economic development and ecological environmental protection, in order to avoid its uncontrolled destruction of ecosystem.