东江中游采砂对航道整治的影响

Influence of sand excavation on channel regulation in the middle reaches of the Dongjiang River

东江中游横沥至沥口段航道连续出浅有待整治,而该河段同时又承担采砂任务。为探究在航道扩能升级工程已实施背景下河段采挖砂工程的的可行性,采用深度积分水动力学数值试验,研究航道整治方案和采砂规划同时实施后该河段水深、流速、水面线变化,并结合反馈信息调整航道整治方案。结果表明:在航道整治后实施采砂规划,会直接导致上游水位单调下降以及水流归槽流态恶化等问题,必须通过新一轮整治才能满足通航要求。整体来看,“十三五”采砂规划可以结合航道整治来实现,但将来在保障航道运输能力的前提下,东江河段已无规划采砂工程的客观条件。

The channel from Hengli to Likou in the middle reaches of the Dongjiang River is continuously shallowing and needs to be regulated.Meanwhile,this section undertakes the task of sand mining.To explore the feasibility of sand mining in the river reach under the background of the implementation of waterway expansion and upgrading project,the depth integral hydrodynamics numerical experiment is used to study the changes in water depth,velocity,and water surface profile of the reach after the implementation of the channel improvement plan and the sand mining plan at the same time.Thus the regulation scheme is adjusted combined with feedback information.The results show that the implementation of sand mining planning after waterway regulation will directly lead to the monotonous decline of upstream water level and the deterioration of water flow in the channel.So a new round of regulation must be carried out to meet the navigation requirements.On the whole,the 13th five-year plan for sand mining can be realized in combination with waterway regulation.However,in the future,under the premise of ensuring the waterway transportation capacity of the channel,the Dongjiang River reach has no objective condition for planing sand mining projects.