岔巴沟流域淤地坝对泥沙存贮-释放的影响(英文)

Effects of check-dams on sediment storage-release in Chabagou Watershed

为分析黄河中游流域产输沙对人类干预增强的响应机制,该文选取岔巴沟为坝系小流域研究区,探讨淤地坝的建设和发展对流域内泥沙存贮-释放时空变化的影响。研究表明,20世纪80年代岔巴沟处于泥沙存贮状态,10a平均泥沙输移比为0.325,经分析,始于20世纪50年代,并于60、70年代得到发展,80、90年代趋于稳定的岔巴沟淤地坝拦截了大量泥沙是造成泥沙存贮的主要原因。和拦沙作用相比,其减少高含沙水流发生频率,降低高含沙水流发育程度的作用更大。值得注意的是,淤地坝在几十年的发展过程中可淤库容显著下降,多数原有坝地淤满,加上20世纪80年代以后坝体建设速度减缓,以及设计标准低,后期管理和维护不利,垮坝和毁坝造成泥沙再释放的潜在性在增加。因此,今后在对淤地坝作为一项重要的水保措施引起足够重视的同时,维护和巩固现有淤地坝的拦泥库容也非常必要。

For clarifying the response of sediment yield to the strengthening of human interventions in the middle Yellow River, Chabagou Watershed was selected as the study area to explore the relationship between development of check-dams and dynamic of sediment storage-release both in time and space.Construction of check-dams in the Chabagou Watershed started in the late 1950s,speeded up swiftly in the 1960s and 1970s,and nearly stopped in the 1980s and 1990s.The results showed that most of eroded sediment was stored in the Chabagou Watershed in the 1980s,with a sediment delivery ratio of 0.325.The low sediment delivery ratio can be attributed to the check-dams,which can not only trap sediment,but also reduce the frequency and intensity of hyper-concentrated flow to a greater extent.However,it is worth noting that the storage capacity of check-dams in the Chabagou Watershed had been decreased significantly due to filling up of early built dams as well as slowdown of dam construction since the 1980s.Moreover,the potentiality of sediment release from destroyed dams is increasing as a result of low design standards and poor maintenance of existing dams.Therefore,the role of check-dams as soil and water conservation measures should be paid adequate attention in the future.It is necessary to strengthen construction and management of check-dams for maintaining and even promoting their sediment trapping capacity.