Title: Assessment of Artificial Intelligence Models for Estimating Lengths of Gradually-Varied Flow Profiles
Journal: Complexity
Year: 2021
Volume number: 2021
Article ID: 5547889
Pages: 1-11
DOI: 10.1155/2021/5547889
Abstract: The study of water surface profiles is beneficial to various applications in water resources management. In this study, two artificial intelligence (AI) models named artificial neural network (ANN) and genetic programming (GP) were employed to estimate the length of six steady GVF profiles for the first time. The AI models were trained using a database consists of 5154 dimensionless cases. A comparison was carried out to assess the performances of the AI techniques for estimating lengths of 330GVF profiles in both mild and steep slopes in trapezoidal channels. The corresponding GVF lengths were also calculated by 1-step, 3-step and 5-step direct step methods for comparison purposes. Based on six metrics used for the comparative analysis, GP and ANN improve five out of six metrics computed by 1-step direct step method for both mild and steep slopes. Moreover, GP enhanced GVF lengths estimated by 3-step direct step method based on three out of six accuracy indices when the channel slope is higher and lower than the critical slope. Additionally, the performances of the AI techniques were also investigated depending on comparing the water depth of each case and the corresponding normal and critical grade lines. Furthermore, the results show that the more number of sub-reaches considered in direct method, the better results will be achieved with the compensation of much more computational efforts. The achieved improvements can be used in further studies to improve modeling water surface profiles in channel networks and hydraulic structure designs.
Keywords: Water surface profile, Gradually-varied flow, artificial neural network, genetic programming, open channel hydraulics