Optimization of the Two-Dimensional Hydrodynamic Model for the Ottawa River

准确、快速的河流流场估算对于合理规划防洪、环境影响评价、危险物质泄漏环境应急响应、资源管理、气候变化社会经济影响评估等具有重要意义。随着计算技术的进步，河流水力学数值模拟已变得可行和普及。然而，大多数现有的模型和建模工作仍然停留在学术水平和/或为实现非常具体的工程项目而开发，例如水利工程结构的设计和洪泛区的评估。非常有限的河流模拟项目已升级到业务水平，结合环境条件的持续波动，不断预测高质量的水流，以满足业务需要。当河流模型运行时，大多是一维的，用于评估水位。本研究的主要目的是设计和优化渥太华河的二维水动力模型，以支持该水系的应急响应。

An accurate and fast estimation of the current flow fields in rivers is crucial for sound planning of flooding prevention, environmental impact assessment, responding to environmental emergencies related to spill of hazardous substances, resource management, and assessment socio-economical impacts of climate change. With the advance in computing techniques, numerical modeling of river hydraulics has become feasible and popular. However, most of the existing models and modelling works that were remained at the academic level and/or were developed to achieve very specific engineering projects, such as the design of hydrotechnical structures and assessment of floodplain. Very limited river modelling projects have been escalated to the operational level in which high-quality current are being predicted continuously integrating the continuous fluctuations in the environmental conditions to respond to operational needs. And when river models are run operationally, there mostly one dimensional and used to assess water level. This research aims primarily to design and optimize a two-dimensional hydrodynamic model for the Ottawa River for operational applications to support emergency response in that water system. Specifically, the first objective of this project is the develop a two-dimensional hydrodynamic model for the Ottawa River from Chat Falls to Carillon to predict horizontal current field with high special resolution to capture complex flow patterns, such as flow recirculation and dispersion. The second objective is to optimize the computational costs without lowering the prediction accuracy, based on a comprehensive analysis of the influence of local mesh resolution on the calculated water level, current velocity, and secondary flows, etc. The developed model will be carefully calibrated and validated against observational data. The computational mesh of the developed model will be highly optimized and this optimization can significantly increase the model efficiency without obviously impacting the model accuracy. This research includes preparing a digital elevation model based on height, Open Street, and navigational maps with the assistance of ArcGIS, determining the computational area, generating various meshes using different setting parameters in BlueKenue, conducting mesh sensitivity analyses and performing simulations using TELEMAC, calibrating the models, and preparing a technical report to describe the study and its findings.