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本文揭示了峡谷与宽谷河道水流结构特性与阻力损失的机理和同异，指出前者的综合糙率常比后者大１～３倍，其原因除了通常认识的周界粗糙度不同有影响外，主要因素是河型和断面形态不同，紊流涡体的产生、规模、强度和分布不同，集中表现在水流内部结构不同所引起的能损不同的结果．论证了阻力系数公式（５）仍可用于三维水流。但卡门常数Ｋ值不再是０．４；峡谷河道水流的Ｋ值可用式（８）或式（９）求解。宽阔河道水流的Ｋ值可用文献［４］的公式计算．在动床水流中，Ｋ值不仅是表征流速分布变化的一个参数，也是衡量水流阻力系数变化和床面形态定性变化的一个指标，是阻力系数的重要组成部份．引入紊流能损理论（即Ｋ值的变化）之后，水流阻力变化规律便与水流结构变化和床面形态变化建立起有机的联系，取得了与实测值基本一致的结果，解决了现有的糙度阻力系数公式无法求解超高（低）阻力的难题．
This paper reveals the mechanism and similarities and differences of water flow structural characteristics and resistance loss in the valley and wide valley, and points out that the former generally has 1 to 3 times higher comprehensive roughness than the latter, except for the commonly recognized perimeter roughness , The main factor is the different shape of the river and the cross section. The turbulent eddies are produced in different scales, intensities and distributions, concentrating on different results caused by the different internal structures of the water flow. It is demonstrated that the drag coefficient formula (5) can still be used for three-dimensional water flow. But the Carmen constant K value is no longer 0.4; K value of canyon river flow can be solved by Eq. (8) or Eq. (9). K value of wide river flow can be calculated using the formula of [4]. In moving bed water flow, K value is not only a parameter to characterize the change of flow velocity distribution, but also an index to measure the change of water flow resistance coefficient and the qualitative change of bed morphology, which is an important part of the drag coefficient. After introducing the theory of energy loss of turbulence (ie, the change of K value), the regularity of water flow resistance has established the organic connection with the change of water flow structure and the change of bed morphology, and has basically obtained the same result with the measured value, Roughness coefficient of resistance formula can not solve the problem of ultra-high (low) resistance.