适应水位变化的库岸生态防护带设计——以重庆汉丰湖为例

Design of Reservoir Bank Ecological Protection Zone Adapting to Water Level Changes——A Case Study of Hanfeng Lake in Chongqing

三峡水库蓄水后,水位季节波动给消落带造成了极大的环境胁迫,大大削弱了消落带的生态屏障功能。在消落带及其以上临近区域构建生态防护带可以有效降低水土流失程度,削减库区农业面源污染,有利于保障三峡水库的生态环境安全,促进可持续利用。以重庆开州区汉丰湖北岸乌杨坝段库岸为例,研究反季节水位变动背景下的库岸生态防护带建设的模式和方法,提出多带多功能缓冲系统模式。阶段性实验研究结果表明,多带多功能缓冲系统面临冬季深水淹没及夏季高温干旱交替的逆境,植被种类、植被结构均表现出良好的韧性适应,有效发挥了湖岸稳固、水质净化、生物多样性保育及景观美化优化等综合生态服务功能,可为具有季节性水位变动的湖、库岸带生态修复提供科学依据及技术范式参考。

The seasonal fluctuation of the water level in the Three Gorges reservoir(TGR)has brought great environmental stresses to the littoral zone,the ecological defense function of the littoral zone is weakened or lost.So,in the littoral zone and its above neighboring region,the construction of ecological protection zone can decrease the soil erosion and levels of the agricultural non-point source pollution,which is beneficial to the ecological environment safety and sustainable utilization of Three Gorges Reservoir.Taking the reservoir bank of Wuyangba section on the northern shore of Hanfeng Lake in Kai County,Chongqing as object,this paper studied the restoration mode and method of the reservoir bank ecosystem in the off-season water level fluctuation background and proposed the multi-stripe,multi-functional buffer system.The results proved the success of the multi-stripe,multi-functional buffer system in facing the adversity of deep water inundation in winter and alternating high temperature and drought in summer,both plant species and vegetation structure showed good resilience and adaptability,and the comprehensive ecological service functions such as lake shore stability,water purification,biodiversity conservation,and landscape optimization were effectively exerts.This study was a new exploration of ecological bank structure in drawdown zone,providing a scientific basis and technical paradigm reference for the ecological restoration of lakes and reservoirs with seasonal water level fluctuations.