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自改革开放以来,韩江河道采砂迅速发展,一开始主要在下游各分支河段采砂,采砂导致下游河段特别是西溪严重下切,水位下降,同时改变了东溪、西溪分流比。除了河道采砂外,导致下游河道严重下切的原因还有上游的水土保持减沙和水利工程拦沙的作用,但最主要的原因是河道采砂。近年来,采砂活动转移到了中游河段。选取位于韩江中游的留隍水位站以及相邻的三河坝水位站和潮安水文站开展研究。通过比较采砂前、后两个时段多年平均水位发现,采砂后留隍站的平均水位下降了0.6 m;上游、下游相邻水文站水位的对比分析和3个站年径流量变化分析结果显示,采砂导致中游河道发生一定程度的改变,并且平均水位下降;虽然目前中游河道采砂对河势稳定、防洪安全影响不大,但从长期发展看,仍然有潜在的不确定性影响;另外,韩江河道采砂对航道通航安全、涉水建筑物以及对生态环境等方面也有不同程度的影响。
Since the reform and opening up, sand mining in the Hanjiang River has been developing rapidly. From the beginning, sand mining was mainly carried out in all branches of the lower reaches of the river. Sand mining led to severe undercutting of the lower reach, especially to Xixi River and a decrease of water level. Meanwhile, diversion ratios of Dongxi and Xixi were changed. In addition to river sand mining, the reason for the serious undercutting of the downstream river channels is also the role of soil and water conservation and sediment reduction upstream of the river, but the most important reason is river sand mining. In recent years, sand mining activities moved to the middle reach. Select the left Han water level in the middle reaches of the Hanjiang River Station and the adjacent water level station and the Sananba Chao An hydrological station to carry out research. By comparing the average water level of the two periods before and after sand mining, it is found that the average water level of the station left after the sand mining decreased by 0.6 m. The comparative analysis of the water level of the upstream and downstream hydrological stations and the analysis of the annual runoff change of the three stations It shows that sand mining leads to a certain degree of change in the middle reaches of the river and a decrease in average water level. Although sand mining in the middle reaches of the river has little effect on the stability of the river and flood control, there are still potential uncertainties in terms of long-term development. In addition, the sand mining of the Hanjiang River also has different degrees of impact on navigational navigation safety, wading buildings, and ecological environment.