This paper presents recent developments to River1D's (the University of Alberta's public-domain hydrodynamic and river ice process model) channel network modelling capabilities. While previous versions of the model assumed equal water surface elevations through the junction, the approach presented in this paper takes into account the significant physical effects at channel junctions (such as gravity and flow separation forces, and channel resistance). The adapted approach is also equipped with the ability to dynamically change junction configurations (i.e. diverging to converging or vice versa) as the result of flow reversals. The intent here was to develop an approach that would permit the simulation of flow in a channel network that includes the more important physical effects at junctions but without the need to adjust model parameters or redefine junctions should a flow reversal occur. This momentum based approach to simulate junctions is assessed using a series of steady and unsteady tests using a 2D model, the University of Alberta's River2D, for comparison. For the diverging junction tests, the proposed 1D network model performed very well with respect to the discharge split. The model accurately simulated the water surface elevation in the two receiving channels but tended to overestimate the water surface elevation immediately upstream of the junction, perhaps attributable to model discretization and/or neglecting the centrifugal forces acting on the main channel as the lateral channel branches off. For the two parallel channels with a perpendicular connecting channel tests, the 1D model agreed well with the 2D model for all steady and unsteady tests. The unsteady test results demonstrated how capable the 1D model is at handling transient flow reversals. The model is then applied to a network of channels in the Mackenzie Delta. The model was calibrated and validated for three open water events, and subsequently used to simulate flow conditions during the 2008 breakup. Model results agreed well with observed water level data collected using data loggers. A comparison of the model flows for the pre-jam and ice-jam conditions suggests that ice jamming can significantly impact the distribution of flow in the upper Mackenzie Delta. For the ice-jam conditions, the simulated flow reversal in the Peel Mackenzie Connector is consistent with observations in this channel during the 2008 breakup.

本文介绍了River1D 的最新进展（阿尔伯塔大学的公共领域水动力和河冰过程模型）渠道网络建模能力。虽然模型的先前版本假设通过连接点的水面高度相等，但本文中提出的方法考虑了通道连接处的显着物理效应（例如重力和流动分离力以及通道阻力）。适应的方法还配备了动态改变交汇点配置的能力（即发散到会聚，反之亦然）作为流动逆转的结果。此处的目的是开发一种方法，允许模拟通道网络中的流动，其中包括连接处更重要的物理效应，但如果发生流动逆转，则无需调整模型参数或重新定义连接点。河流2D，进行比较。对于发散结点测试，建议的一维网络模型在排放分流方面表现非常好。该模型准确地模拟了两个接收渠道的水面高程，但往往高估了紧接在交汇处上游的水面高程，这可能是由于模型离散和/或忽略了侧向渠道分支时作用在主要渠道上的离心力. 对于具有垂直连接通道的两个平行通道测试，一维模型与二维模型在所有稳态和非稳态测试中都非常吻合。不稳定的测试结果证明了 1D 模型在处理瞬态流动逆转方面的能力。然后将该模型应用于 Mackenzie Delta 中的通道网络。该模型针对三个开放水域事件进行了校准和验证，随后用于模拟 2008 年破裂期间的流动条件。模型结果与使用数据记录器收集的观察到的水位数据非常吻合。对预堵塞和冰堵塞条件的模型流量的比较表明，冰堵塞可以显着影响上麦肯齐三角洲的流量分布。对于冰塞条件，Peel Mackenzie Connector 中模拟的流动逆转与 2008 年解体期间在该通道中的观察结果一致。对预堵塞和冰堵塞条件的模型流量的比较表明，冰堵塞可以显着影响上麦肯齐三角洲的流量分布。对于冰塞条件，Peel Mackenzie Connector 中模拟的流动逆转与 2008 年解体期间在该通道中的观察结果一致。对预堵塞和冰堵塞条件的模型流量的比较表明，冰堵塞可以显着影响上麦肯齐三角洲的流量分布。对于冰塞条件，Peel Mackenzie Connector 中的模拟流动逆转与 2008 年解体期间在该通道中的观察结果一致。