山区河流航道整治施工对水生态环境的影响

Influence of river channel regulation construction on water ecological environment in mountainous rivers

山区河流航道整治一般采取筑坝、疏浚、炸礁、护岸等工程,在施工中不可避免对现状水生态环境造成扰动。以岷江下游航道整治一期工程为例,通过对代表性河段施工前后的水质、浮游生物、底栖动物、鱼类等种类和资源量开展现场监测,研究发现:施工前后水体化学需氧量、五日生化需氧量、氨氮、总磷、石油类、悬浮物的浓度有所升高,但均未超过相关标准限定值;藻类、水生维管束植物、浮游动物、底栖动物、鱼类等施工前后无明显减少。因此通过合理的时间、空间的施工避让,航道整治施工对山区河流水生态环境的影响较小。

Spur dikes,dredging,reef blasting,bank protection,and other projects are generally adopted for river channel regulation in mountainous rivers,which inevitably causes disturbance to the current water ecological environment during construction.Taking the first phase of the river channel regulation project in the lower reaches of the Minjiang River as an example,this paper conducts field monitoring of typical reaches in the whole process of construction,involving water quality,plankton,benthic animals,fish and other species,and resource quantity.It is found that the concentrations of chemical oxygen demand,five-day biochemical oxygen demand,ammonia nitrogen,total phosphorus,petroleum,and suspended matter increase after construction,but they do not exceed the limits of relevant standards.There is no significant reduction in algae,aquatic vascular plants,zooplankton,benthic animals,fish,etc.before and after the construction.Through reasonable construction avoidance in time and space,the influence of river channel regulation on the water ecological environment in mountainous rivers can be alleviated.