Hydrodynamic Modeling of a Tropical Tidal River Using the Dynamic Estuary Model (DYNHYD5): A Case Study in Sibu Laut River, Sarawak, Malaysia

Chen-Lin Soo,Lee Nyanti,Teck Yee Ling

doi:10.1155/2018/8726752

Chen-Lin Soo, Lee Nyanti + Show 1 more

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https://doi.org/10.1155/2018/8726752

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Abstract

Application of the Dynamic Estuary Model (DYNHYD5) in a tropical tidal river is limited. The successfully calibrated and validated hydrodynamic model is valuable in subsequent water quality simulation for environmental management. Hence, a hydrodynamic modeling approach using the DYNHYD5 was conducted in a tropical tidal river in Malaysia. Samplings were conducted in the Sibu Laut River to collect the hydrology data for model simulation. The model was calibrated and validated by comparing the simulated flow and mean depth with the field data at different simulation periods of time. The results showed that the model DYNHYD5 was successfully calibrated with channel flows and mean depths and then reproduced with good agreement in validation. The observed and simulated data were linearly correlated (R2 > 0.8) with values of slope γ ranging from 0.891 to 1.204 in both calibration and validation. The Nash–Sutcliffe coefficient of efficiency (NSE) of more than 0.7 in both calibration and validation also indicated satisfactory comparison between the observed and simulated data. The result indicated that the application of the DYNHYD5 is feasible in a tropical tidal river in Malaysia.

Highlights

Introduction e Dynamic Estuary ModelDYNHYD5 [1] is a onedimensional hydrodynamic model for simulating water velocities, flows, volumes, and heads using a channel junction approach. e DYNHYD5 is the most recent version of the modeling software and is distributed and supported by the USEPA’s Center through the WASP5 and WASP6 modeling software [2, 3]. e model utilizes a channel-junction model network to perform simulations
16 junction locations were chosen along the Sibu Laut River and tributaries. e placement of model junctions led to the definition of 15 model channels
In the hydrodynamic modeling of the Venice channels, Umgiesser and Zampato [6] found that the velocity was more sensitive to the variations of Manning’s coefficient than elevation. e average error of elevation remained constant, while the average error of current speed ranged from 6.1 to 12.1 cm/s when Manning’s coefficient varied from 0.020 to 0.050. e sensitivity analysis in the present study shows that the inflow has major impact on the channel flow but has minor impact on the mean depth

Summary

Introduction

Introduction e Dynamic Estuary ModelDYNHYD5 [1] is a onedimensional hydrodynamic model for simulating water velocities, flows, volumes, and heads using a channel junction (link-node) approach. e DYNHYD5 is the most recent version of the modeling software and is distributed and supported by the USEPA’s Center through the WASP5 and WASP6 modeling software [2, 3]. e model utilizes a channel-junction (link-node) model network to perform simulations. DYNHYD5 [1] is a onedimensional hydrodynamic model for simulating water velocities, flows, volumes, and heads using a channel junction (link-node) approach. E model utilizes a channel-junction (link-node) model network to perform simulations. Rivers, or estuaries are broken down into a series of channels (links) and junctions (nodes). E model has the capability of simulating complex branching river systems with a maximum of six links either leaving or entering a single junction. E successfully calibrated and validated model can be linked with the Water Quality Analysis Simulation Program (WASP) for water quality modeling. E use of modeling in simulating river flows and water quality is lacking in tropical countries like Malaysia due to lack of data to calibrate and validate the models. The channel flow and velocity variations in the river Mahadayi (Mandovi) and estuarine zone have been predicted for pre- and post-dam construction project scenarios with DYNHYD5 [7]. e successfully calibrated and validated model can be linked with the Water Quality Analysis Simulation Program (WASP) for water quality modeling.

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