Preparation of a Hydrodynamic model of. Detroit River- St. Clair River waterways. with Telemac-2D

Transcription

1 Preparation of a Hydrodynamic model of Detroit River- St. Clair River waterways with Telemac-2D Controlled Technical Report CHC-CTR-085 March 2009

2 CTR-CHC-085 NRC-CHC has prepared this report for the International Joint Commission (IJC) based on data supplied by IJC, its Commissioners, staff, consultants, or contractors. NRC-CHC does not guarantee the accuracy or validity of such data, and does not guarantee that any software used in the work reported herein is free from errors not disclosed so far. In preparing this report and making it available to IJC, NRC-CHC expressly is not undertaking to render professional services or provide advice to, or on behalf of, any third party. Furthermore, NRC-CHC expressly is not undertaking to perform any duty owed to any third person or entity by any other person or entity. NRC-CHC does not guarantee that the contents of this report meet the requirements of any third party. The information in this report is directed exclusively to those with the appropriate degree of training and experience to use and apply its contents. This report is provided without any representations, warranties, or conditions of any kind, express or implied, including, without limitation, implied warranties or conditions about the document s fitness for a particular purpose or use, its merchantability, or its non-infringement of any third party s intellectual property. However, NRC warrants that it has not knowingly infringed any other party s intellectual property.

3 Preparation of a Hydrodynamic model of Detroit River- St. Clair River waterways with Telemac-2D Controlled Technical Report CHC-CTR-085 March 2009 Canadian Hydraulics Centre National Research Council Ottawa, Ontario K1A 0R6 Prepared for: International Joint Commission International Upper Great Lakes Study 234 Laurier Avenue West, 22 nd Floor Ottawa, ON K1P 6K6

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5 CTR-CHC-085 i Table of Content 1. Introduction Preparation of the Detroit River Model Model Grid Model Boundaries Model tributaries The Bathymetry Calibration-Verification of the Detroit River Model Preparation of the general St Clair-Detroit-Erie model Modification of the existing St. Clair River Model Calibration of St. Clair River Model Preparation of the general model Simulation of Glacial Isostatic Adjustment Simulation of Wind Effect on Lake Erie Preparation of Hydraulic Performance Curves for the Detroit River References... 20

6 ii CTR-CHC-085 List of Tables Table 1 - Comparison between assumed and simulated levels and flows in the Detroit River channels, after calibration... 7 Table 2 - Comparison between assumed and simulated levels and flows in the St. Clair River channels, after calibration Table 3 - St.Clair Shores levels as a function of Erie Lake for various flows through Detroit River...19 Table 4 - Bar Point levels as a function of Erie Lake for various flows through Detroit River 19

7 CTR-CHC-085 iii List of Figures Figure 1 - Detroit River finite element grid... 2 Figure 2 - Grid detail around bridge to Grosse Ile... 3 Figure 3 - Grid detail around Livingstone navigation channel... 3 Figure 4 - Additional longitudinal bathymetry points along navigation channels... 5 Figure 5 - Roughness coefficients along the channels of Detroit River (Strickler formulation) 8 Figure 6 - Coarser grid downstream of Blue Water Bridge Figure 7 - Overall view of Erie-to-Huron waterways model Figure 8 - Buffalo glacial uplift - effect on water depth at Lakeport Figure 9 - Bar Point glacial uplift - effect on water depth at Lakeport Figure 10 - Wind speed (m/s) applied on Lake Erie Figure 11 - Effect of sudden wind stoppage on water levels on St Clair Lake, at Buffalo and Bay Point Figure 12 - Hydraulic Performance Curves for the Detroit River... 18

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9 CTR-CHC Introduction As part of the International Upper Great Lake Study, several two dimensional numerical models of St. Clair River were developed using Telemac software (Ref. 1 and 3). These models were well calibrated with the and with the 2007 bathymetry surveys of the river and were used extensively to simulate changes that may have occurred in the last 35 years and assess the impacts of these changes on the river hydrodynamics. In order to complete the modeling of the waterways between Lake Erie and Lake Huron, the development of the Detroit River section was required. This section was then merged to the St. Clair River section and later merged to a Telemac grid of Lake Erie. This will allow the study of the dynamic behaviour of the lakes along the waterways: Erie and St. Clair. 2. Preparation of the Detroit River Model 2.1 Model Grid The Detroit model grid covers the whole River from Lake St. Clair to Lake Erie. (See Fig 1). Similarly to the St. Clair River model with Telemac, the grid size is of the order 55 m in the major channels, down to 40 m in the narrower channels. It was thought that it was not necessary to have a finer mesh since this model would be used for overall studies of the system dynamics, and not to investigate local effects. If this kind if detail study is required, it will be easy to refine the mesh at these locations. The triangular grid was generated for its most part using Blue Kenue, a preprocessor for Telemac developed by CHC, with some grid details prepared with TRIGRID. In critical cases, such as the dredged channels, the elements were prepared manually based on the local bathymetric survey points. Details of the grid are shown in Fig. 2. In the preparation if the grid, special attention was given to the jetties and other non-floating docks that protrude forward into the river flow. Extensive use of Google Earth helped in defining the floating from non floating objects. The Detroit River portion of the model has in excess of nodes and elements. The geographic system in which the model was prepared is UTM (Universal Transverse Mercator) zone 17. All levels are referenced to IGLD 85.

10 2 CTR-CHC-085 Figure 1 - Detroit River finite element grid

11 CTR-CHC Figure 2 - Grid detail around bridge to Grosse Ile Figure 3 - Grid detail around Livingstone navigation channel

12 4 CTR-CHC Model Boundaries The shorelines were obtained from several sources. On the Canadian side, it was from the Ontario Ministry of Natural resources, Land Information Ontario ( On the US side, it was obtained from the navigation charts provided by NOAA. 2.3 Model tributaries In the Detroit section of the waterways, the only tributary simulated inflow was the River Rouge with an average constant discharge of 9 m 3 /s obtained from Reference 2. Furthermore, a net inflow of 18 m 3 /s was also simulated for Lake St. Clair (atmospheric and ground water). 2.4 The Bathymetry It was obtained from a 2000 survey by NOAA. It was very complete, covering all channels, natural or dredge, and no major modification had to be performed except in the dredge navigation channels. In these channels, the surveys were done with cross-sectional boat paths which, during the mapping process onto the grid, provided some oscillations in the numerical represention of the botom. Adittional bathymetric points, two longitudinal lines on each side of the channel, were therefore prepared by interpolation, in order to give the proper trough-like shape to the channel, as shown on Figure 4. A few bathymetric points were added in shalow areas where no survey had been done.

13 CTR-CHC Figure 4 - Additional longitudinal bathymetry points along navigation channels (the two lines on both sides of the channel)

14 6 CTR-CHC Calibration-Verification of the Detroit River Model It would have been ideal to calibrate the Detroit River model with steady state level data, as had been the case with the St. Clair River. This would have given reliable sets of flow and levels with minimum errors during the verification process. But the existing stage-discharge relationships are being revised based on recent ADCP survey information, and it would have been difficult to use them, since they would have required corrections factors which are uncertain at the present time. It was therefore decided to use the level and discharge data from David Holtschlag s study (Ref. 2) which presents the calibration of a RMA model prepared by USGS. In it, many ADCP flow measurements were collected over several periods of several days and an average discharge and average level were deduced. In order to calibrate and verify the model, three scenarios from Reference 2 were chosen. They corresponded to: minimum outflow from Lake St. Clair, scenario 1, 5170 m 3 /s, medium outflow from Lake St. Clair, scenario 7, 5869 m 3 /s, maximum outflow from Lake St. Clair, scenario 4, 6567 m 3 /s, The model was run for the three discharges and the bottom roughness of 19 different zones covering the various channels of the River were adjusted until the simulated levels and simulated channel discharges best matched all the measurements. Table 1 shows the final model characteristics compared to the measurements. It shows that the levels were reproduced within 1 cm, except at Gibraltar where a larger error of about 5 cm was observed. The flow split among the various major channels is very good, with an average difference of about 2.5 %. In Table 1, the numbering of the cross sections is the same as defined in the RMA model. The final bottom roughness coefficients are shown in Fig. 5. In the Telemac model, the Strickler formulation was chosen to describe the river bottom resistance. Manning coefficients are simply the inverse of Strickler coefficients.

15 CTR-CHC scenario 1 scenario 7 scenario 4 Q from Lake St Clair measured simulated Difference measured simulated Difference measured simulated Difference St. Clair Shores (m) Windmill Point Fort Wayne Wyandotte Amhertsburg Gibraltar Bar Point cfs m3/s simulated % diff cfs m3/s simulated % diff cfs m3/s simulated % diff Q from St Clair Lake m3/s section section section section section section section section section section section section section section Table 1 - Comparison between assumed and simulated levels and flows in the Detroit River channels, after calibration

16 8 CTR-CHC-085 Figure 5 - Roughness coefficients along the channels of Detroit River (Strickler formulation)

17 CHC-CTR Preparation of the general St Clair-Detroit-Erie model The goal of the project was to prepare a general model of the waterways between Lake Erie and Lake Huron. This was done by merging the three separate grids, St. Clair, Detroit and Erie, and preparing a new set of boundary condition. 3.1 Modification of the existing St. Clair River Model Before merging the three models it was decided to use a coarser grid for the St. Clair portion, so that the time step for the larger model could be increased, and the total number of nodes would be smaller, thus decreasing significantly the model running time. The grid size of the original St. Clair River model was 15 m in the top portion above Black River. Since the new model was going to be used to study general dynamics of the whole system and not detailed changes of local bathymetry, a coarser mesh, with a grid size equivalent to the rest of the river, was prepared. It is shown on Figure 6 which also shows in the background the original 15 m grid. 3.2 Calibration of St. Clair River Model Since the Detroit River portion was calibrated with a new set of flows and levels, the St. Clair River portion had to be calibrated with the same set of measurements. The RMA calibration data were therefore used for the three same scenarios from reference 2. They corresponded to: minimum outflow from Lake Huron, scenario 1, 4905 m 3 /s, medium outflow from Lake Huron, scenario 7, 5604 m 3 /s, maximum outflow from Lake Huron, scenario 4, 6302 m 3 /s, The roughness coefficients on the St, Clair River were adjusted until the simulated levels and simulated channel discharges best matched all the measurements. Table 2 shows the final model characteristics compared to the measurements. In this calibration, the levels were reproduced with a larger error than the Detroit River section; the average error is of the order 6 cm, with a maximum of 13 cm at Dunn Paper. But the flow split among the various estuary channels is still very good, with an average difference in flows of about 2.7%.

18 10 CTR-CHC-085 Figure 6 - Coarser grid downstream of Blue Water Bridge

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20 12 CTR-CHC-085 Calibration St Clair River with RMA data BASED ON 2007 BATHYMETRY Scenario 1 Scenario 7 Scenario 4 Flow from Huron 4905 m 3 /s 5604 m3/s 6302 m 3 /s Measured simulated diff Measured simulated diff Measured simulated diff Lakeport (m) Fort Gratiot (m) Dunn Paper (m) Point Edward (m) Mouth Of Black (m) Dry Dock (m) St. Clair SP (m) Point Lambton (m) Algonac (m) St. Clair Shores (m) Scenario 1 Scenario 7 Scenario 4 cfs m3/s simulated % diff cfs m3/s simulated % diff cfs m3/s simulated % diff Q upstream St Clair Riv m 3 /s Q after chennal Ecarte (section 230) m 3 /s Q chenal Ecarte (section 222) m 3 /s Q north channel m 3 /s Q south channel (section 232) m 3 /s Q north north channel (section 240) m 3 /s Q middle channel (section 242) m 3 /s Q south north channel (section 238) m 3 /s Q cutoff channel (section 236) m 3 /s Q Bassett (section 234) m 3 /s Table 2 - Comparison between assumed and simulated levels and flows in the St. Clair River channels, after calibration

21 CHC-CTR Preparation of the general model The St. Clair River and the Detroit River models were merged together with an existing model of the Lake Erie model. The boundaries for this large model are: the inflow from Lake Huron the outflow into Niagara River at Buffalo The same tributaries and inflows were maintained as previously defined. In the present state of the model no inflow was considered into Lake Erie, but they could be added if required. The general model has in excess of nodes and elements. The geographic system in which the model was prepared is UTM (Universal Transverse Mercator) zone 17. All levels are referenced to IGLD 85. Figure 7 - Overall view of Erie-to-Huron waterways model

22 14 CTR-CHC-085 Three sets of simulations were prepared with this general model: The Glacial Isostatic Adjustment was simulated to assess the effect of glacial tilt in Lake Erie - Lake Huron, on the levels of St. Clair and Huron Lakes, and the conveyance of St. Clair river A simulation of a strong wind on Lake Erie, and its effect on the hydrodynamics of the system Preparation of hydraulic performance curves for the Detroit river section 4. Simulation of Glacial Isostatic Adjustment It is generally agreed that the Glacial Isostatic Rebound would have the effect of raising Fort Gratiot relatively to Toledo, (both cities situated at both ends of St. Clair-Detroit rivers) and raising Buffalo relatively to Toledo (situated at both ends of Lake Erie). The slope of the St. Clair River alone had previously been increased between Fort Gratiot and St. Clair Lake. This simulation was carried-out with the smaller St. Clair River model (Ref. 1), and it was found that for a glacial uplift of 2.5 cm at Fort Gratiot relatively to Algonac, the water depth at Lakeport would decrease by 3 cm, indicating a slight increase in the river conveyance of 75 m 3 /s. Two more glacial movements were simulated separately with the more extensive model which includes Detroit River and Lake Erie: Raising Buffalo relatively to Bar Point at both ends of Lake Erie without changing the slopes of Detroit and St. Clair Rivers. This has the effect of raising the whole Lake Erie level and therefore diminishing the head difference between Huron and Erie. Figure 7 shows that the effect on Lake Huron would be very small with an increase in water depth of 2 cm if Buffalo is raised by 5 cm Raising Fort Gratiot relatively to Bar Point without changing the slope of Lake Erie bottom. Both Detroit and St. Clair River slopes were increased. In this case the effect on Lake Huron would be opposite, with a decrease by 3.5 cm if Fort Gratiot is raised by 5 cm (Fig 8).

23 CHC-CTR Change in depth at Lakeport St Clair Shores= Buffalo= Q from Huron=5680 m3/s Raise Buffalo metre Glacial uplift at Buffalo (cm) Figure 8 - Buffalo glacial uplift - effect on water depth at Lakeport 0.00 Change in depth at Lakeport St Clair Shores= Buffalo= Q from Huron=5680 m3/s metre Raise Fort Gratiot Glacial uplift at Fort Gratiot (cm) Figure 9 - Bar Point glacial uplift - effect on water depth at Lakeport

24 16 CTR-CHC-085 If both type of glacial tilt were considered simultaneously, then it is felt that their effects on Huron level would cancel each other and therefore would be very small, with a minimal change in the conveyance of the St. Clair River. 5. Simulation of Wind Effect on Lake Erie Lake Erie is the shallowest of the Great Lakes, with an average depth of about 20 m, and half of that depth on the West portion of the lake. When the wind blows over the lake, it tends to push water to one of its end. This may cause extensive seiches if strong winds blow in the Southwest to Northeast direction, for a prolonged time. With the new model, we have simulated what happens when the wind stops blowing and the whole lake starts oscillating. A 40 km wind was first applied for 12 hours in a 45 degree direction over Lake Erie only, and then stopped (Fig 10). Time (days) Figure 10 - Wind speed (m/s) applied on Lake Erie Figure 11 shows the corresponding levels at both ends of Lake Erie and in Lake St. Clair. When the water piles up against Buffalo, it dries out Bay Point on the west side, which tends to draws down Lake St. Clair through the Detroit River. When the wind stops blowing, oscillations take place in Lake Erie. In the conditions of water levels and bottom friction with which the model was prepared, these oscillations have a period of about 14 hours. Figure 11 shows also that Lake St. Clair was drawn down by only 1 cm.

25 CHC-CTR Figure 11 - Effect of sudden wind stoppage on water levels on St Clair Lake, at Buffalo and Bay Point

26 18 CTR-CHC Preparation of Hydraulic Performance Curves for the Detroit River A set of level-discharge relationship curves was prepared for the Detroit River. It is shown on Figure 12 and Table 3, where all curves correspond to steady states. In the past 30 years Lake Erie levels were approximatively 40 cm above Chart datum set at m (IGLD 1985). The levels of the lake were therefore varied from to m in order to cover the full range of observed levels variations in the past 30 years. Over the same period, monthly average discharges varied from 4050 to 7080 m 3 /s with a mean of 5559 m 3 /s. The Performance curves were therefore run with flows from 4000 to 7000 m 3 /s. In these simulations the Lake level was taken about 3 km downstream from Bar Point. For reference, Table 4 provides the relationship between the Erie Lake level and the level at Bar Point Level at St. Clair Shores, based on Telemac model calibrated with flow and level data from RMA report (flow in m 3 /s) Level St. Clair Shores Level Lake Erie Figure 12 - Hydraulic Performance Curves for the Detroit River

27 CHC-CTR Level at St. Clair Shores (m IGLD datum ) Lake Erie Q Upstream (m 3 /s) Table 3 - St.Clair Shores levels as a function of Erie Lake for various flows through Detroit River Level at Bar Point Lake Erie Q Upstream (m 3 /s) Table 4 - Bar Point levels as a function of Erie Lake for various flows through Detroit River

28 20 CTR-CHC References 1. Preparation of a hydrodynamic model of St. Clair River with Telemac-2D, to study the Impacts of Potential Changes to the Waterway; Canadian Hydraulics Centre, National Research Council, Ottawa, Ontario. March 2008, CHC-CTR David Holtschlag, John Koschik, A Two Dimensional Hydrodynamic Model of the St. Clair-Detroit River Waterway in the Great Lakes Basin, Detroit district, US Army Corps of Engineers, report Hydrodynamic model of St. Clair River with Telemac-2D, Phase 2; Canadian Hydraulics Centre, National Research Council, Ottawa, Ontario. March 2009, CHC-CTR-084