初论采沙对河床的影响及控制

对河道采沙从流态变化和对河床的影响进行了分析，分析表明：（ａ）采沙使河床局部变形，打破了水沙运动的平衡，采沙坑对水流的作用类似于跌坎，相应地横向次生流和平面流场也被迫调整（ｂ）水流流态变化引起溯源冲刷 ，进而导可床全面调整，影响河床稳定，建议加强统一管理，以科研成果为基础指导有序采沙，力求变害为利。

A Study on the Effect of Sand-Gravel Extraction on Riverbed and its Control

A study is carried out on the variation of the flow state and the effects of the sand gravel extraction on the riverbed. The sand gravel extractions force the riverbed to deform,resulting in the loss of equilibrium between the river flow and the riverbed. The action of a sandpit is similar to that of a drop pit;transverse circulation and the total flow field have to adjust themselves correspondingly. The variations of flow pattern cause headwater erosion, and the sand gravel extraction will result in comprehensive adjustment of riverbed ,affecting riverbed stability. It is suggested that united management be strengthened and sand gravel extraction be controlled based on scientific studies on sand gravel extraction.