延河流域骨干坝拦沙量反推与未来可拦沙年限预测

Sediment Retention Calculation and Future Functional Life Prediction of the Key Check Dams in the Yanhe River Basin

定量研究延河流域淤地坝拦沙贡献率和未来可拦沙潜力,对流域淤地坝建设效益分析具有重要的参考价值。根据延河流域1952—2018年的径流输沙数据和2011年全国水利普查中的骨干坝建坝年限、控制面积、总库容和淤积库容等资料,构建了延河流域骨干坝拦沙量反推计算模型,计算了延河流域骨干坝逐年拦沙量与减沙贡献率,预测了骨干坝未来可拦沙年限。结果表明:不同年代延河流域骨干坝年均拦沙量持续增加,2000—2011年多年平均拦沙量为401万t/a,达到最大值;人类活动是延河流域年输沙量减少的主要因素,1997—2005年和2006—2011年人类活动对延河流域减沙量的贡献率分别为63.44%和84.98%;骨干坝拦沙量在人类活动减沙量中的占比呈减小趋势,1997—2005年占比24.67%,2006—2011年占比7.46%;截止2019年,延河流域62%的骨干坝未来拦沙年限为30年以内,并且北部骨干坝未来可拦沙能力大于南部骨干坝。研究结果可为延河流域水土流失防治与效益评价、水土保持措施规划与布局以及流域综合管理等提供参考依据。

The quantitative research on the contribution rate and the future deposit potential of check dams in the Yanhe River Basin has important reference value for evaluating the construction benefits of check dams.Based on the runoff and sediment transport data of the Yanhe River Basin from 1952 to 2018 and the data of the construction period,control area,total storage capacity,and the sedimentation storage of the key check dams in the 2011 National Water Conservancy Census,the inverse calculation model for the sediment retention capacity of the key check dam was established.The annual sediment retention and sediment reduction contribution rate of the key check dams in the Yanhe River Basin were calculated,and the future sediment retention years of the key check dams was predicted.The results showed that the annual average sediment interception of the key check dams in the Yanhe River Basin continued to increase in different periods,and the average annual sediment interception from 2000 to 2011 was 4.01 million ton per year,which was the maximum value among the different periods.The human activity was the main factor for the decreased annual sediment transport in the Yanhe River Basin,and the contribution rates of the human activity to the sediment reduction in the Yanhe River Basin from 1997 to 2005 and 2006 to 2011 were 63.44%and 84.98%,respectively.The proportion of sediment reduction caused by the key check dams accounting for that caused by the human activities was decreased,from 24.67%of 1997-2005 to 7.46%of 2006-2011.By the end of 2019,the future sediment-retaining period of 62%of the key check dams in the Yanhe River Basin was less than 30 years.Compared with those in the southern region,the key check dams in the northern Yanhe River Basin has the stronger future sand-retaining ability.The results in this study could provide reference for soil erosion control and benefit evaluation,soil and water conservation measures planning and layout,and comprehensive management of the Yanhe River Basin.