河堤环境效应略论

Brief Discussion About Environmental Effect of River Dyke

河流堤防的初始环境效应主要是防止河水泛滥和与河川争地。其派生的主要环境效应有 :抬高水位 ,增大流速 ;延迟或堵塞支流汇水 ;造成水资源的浪费和短缺 ;中断土地肥力的自然培育过程 ;破坏土壤表层盐分的自然洗涤机制 ;加速土地沙化进程 ;改变流域结构 ,破坏河流环境生态功能。为防止河水泛滥并侵占河流的生存空间而修筑堤防 ,却引起了环境质量下降甚至导致环境恶化 ,人类应从中汲取沉痛的教训。

The original functions of river dyke were mainly to prevent flood and to vie with river for land. Its deriving effects include raising water level and current velocity, delaying of cutting current from tributary to main river, squandering water resources and causing their shortage, breaking off process of naturally-recovering land fertility, destroying mechanism of naturally-washing-off salt and alkali in the surface of land, accelerating progress of land desertification, changing the structure of drainage area and destroying the environmental function of river. Constructing dyke to prevent flood and occupy river's survival space, however, caused decrease of environmental quality and even led to environmental deterioration. Human should draw a bitter lesson from it.