荆江沙质河床减缓冲刷的节点整治措施研究

受气候变化和上游建库等人类活动影响,荆江河段来沙减少,河床发生显著冲刷,引起枯水位下降和荆江三口分流减少。为缓解河床冲刷带来的不利影响,首先分析确定了荆江沙质河床的可控河段,然后提出了护底带与局部潜坝相结合的节点整治措施。数学模型计算表明,整治工程实施20 a后,荆江沙质河段总冲刷量可减少15%左右,枯水位下降值可减小0.2~0.8 m,而洪水位壅高值在0.1 m内。综合分析认为,整治工程对于减缓河床冲刷与枯水位下降具有一定效果,同时对河势稳定、防洪等影响不大。

Study on node regulation measures for reducing scour in Jinjiang sandy river bed

Under the influence of climate change and human activities such as reservoir construction, the sediment transportation in the Jinjiang River has significantly reduced, and river bed has been greatly scoured, resulting in water level lowering in dry season and diversion reduction of the three outlet distributaries of the Jinjiang River. In order to relieve the adverse effects of riverbed scouring, we identified the controllable reaches in the Jinjiang sandy riverbed, and then put forward the node regulation measure using the combination of bottom protection belt and local submerged dam. According to the mathematical model calculation, the scouring quantity in Jinjiang sandy river can reduce by about 15% after twenty years of implementing node regulation, and the water level in dry season can reduce by 0.2~0.8 m; while flood water level can rise within 0.1m. Comprehensive analysis indicates that the node regulation measure has certain effects on reducing the scouring of the river bed and lowering the water level in dry season, but it has little influence on the stability of river regime and flood control.