Open-Channel Hydrodynamic Numerical Simulation of Topographically Uncharted River Based on Observational Data-Driven Method

The integrity and accuracy of river-terrain data directly affect the results of open-channel one-dimensional hydrodynamic numerical simulation. However, there are topographically uncharted rivers in the real world, and their hydrodynamic processes are difficult to simulate. This study investigated topographically uncharted rivers and investigated publicly available digital elevation model data to generalize their cross sections. The sensitivity of the shape parameters of the generalized cross sections and river roughness to open-channel hydrodynamic simulation was analyzed using the Latin hypercube one factor at a time method. The results show that the sensitivity of the bottom width of the cross section was considerably less than that of the bottom elevation and roughness. The sensitive parameters were optimized by a data-driven method, and the optimized section was applied to the simulation model calculation. The proposed key factor identification and cross-section generalization methods greatly improved the calculation speed. The method was applied to the topographically uncharted river of the Zhentouba I-Shaping II to simulate the hydrodynamic processes of the whole river. The mean error in the water level was verified to be less than 0.15 m, and the Nash-Sutcliffe efficiency coefficient was greater than 0.9, which proves the validity of the method.