基于不同水文学方法的河流生态基流研究——以渭河甘肃段为例

Study on River Ecological Base Flow Based on Different Hydrology Methods-A Case Study of Weihe River in Gansu Province

[目的]明确渭河甘肃段生态基流推荐值,揭示不同水文学方法计算渭河甘肃段生态基流的适用性,进而为渭河甘肃段生态基流保障提供参考。[方法]基于北道水文站近65年月径流资料,采用Tennant法、传统年内展布法、改进年内展布法及基流比例法对渭河干流甘肃段的河流生态基流值进行了计算对比。[结果]Tennant法计算的渭河甘肃段控制站生态基流应控制在1.12~12.38 m^(3)/s;传统年内展布法计算生态基流应控制在0.72~4.13 m^(3)/s;改进年内展布法计算的渭河甘肃段控制站生态基流应控制在1.48~8.19 m^(3)/s;基流比例法计算的渭河甘肃段控制站生态基流应控制在1.76~12.37 m^(3)/s。4种方法计算得出的河流平均生态基流分别占多年平均流量的16.89%,6.59%,12.69%,15.83%。[结论]基流比例法与改进年内展布法对于非汛期基流分配效果较为良好,基流比例法计算结果可作为渭河甘肃段生态基流推荐值,未来应加强河道的生态基流保障研究。

[Objective]The aims of this study is to determine the recommended value of ecological base flow and reveal the applicability of different hydrographic methods for calculating the ecological base flow of the Weihe River in Gansu,and then to provide reference for the ecological base flow guarantee in the Weihe River in Gansu section.[Methods]Based on the monthly runoff data of Beidao hydrology station in recent 65 years,the ecological base flow values of the Weihe River in Gansu section were calculated and compared by using Tennant method,traditional annual spreading distribution method,improved annual spreading distribution method and base-flow ratio method.[Results]The ecological base flow of the control station in the Weihe River in Gansu calculated by Tennant method should be controlled between 1.12~12.38 m^(3)/s.The ecological base flow calculated by traditional annual distribution method should be controlled within 0.72~4.13 m^(3)/s.The ecological base flow calculated by improved annual distribution method should be controlled in the range of 1.48~8.19 m^(3)/s.The ecological base flow calculated by base flow ratio method should be controlled between 1.76~12.37 m^(3)/s.The average ecological base flow calculated by the three methods acco unted for 16.89%,6.59%,12.69%,and 15.83%of the annual average flow,respectively.[Conclusion]The base flow proportion method and the improved annual distribution method have good effects on the allocation of base flow in non-flood season.The results of the base-flow ratio method can be used as the recommended values of the ecological base flow of the Weihe River in Gansu,and the study of ecological base flow guarantee should be strengthened in the future.