Title

Data From: Historical Changes in Lower Columbia River and Estuary Floods: A Numerical Study

Document Type

Dataset

Publication Date

8-2019

Subjects

Oceanography -- Columbia River Estuary (Or. and Wash.) -- Mathematical models, Columbia River Estuary (Or. and Wash.)

Abstract

Over the past 150 years, the Lower Columbia River Estuary (LCRE) controlling depth has approximately doubled, the majority of historical wetlands and floodplain have been reclaimed, numerous infrastructure projects have altered and confined flow pathways, and significant natural and anthropogenic changes to the discharge hydrograph have occurred. To investigate the effect of these changes on tides, river slope, and flood water levels, we construct and validate numerical models that simulate flow over late 19th century and present-day bathymetry. The models are validated using archival (1853-1877) and modern tide measurements throughout the LCRE, and river stage measurements from the tidal river (1876-present). Historical flood plain roughness and levee heights are validated iteratively, by requiring simulations to match the observed roll-off in the river stage rating curve during floods. Measurements and model results show that environmental change has amplified tidal constituents, with peak change about 60km from the coast. By contrast, increased depth has reduced river slope for low and moderate river discharge. For rarely observed extreme floods of 30x103 m3s-1, simulated modern water levels exceed historical in Portland (OR). These observations highlight competing hydrodynamic effects, which are investigated by scaling the St Venant equations for a simulated 25x103 m3s-1 flood: while larger modern depth reduces frictional effects and decreases surface slope, reduced floodplain access confines modern flow into channels, increasing velocity, bed stress and water levels. However, the highly frictional historical floodplain conveyed little flow, limiting the effect of floodplain to storage effects; hence, most simulated historical floods exceed modern levels.

Description

The data supports a manuscript to be published in the Journal of Geophysical Research: Oceans

Data Description - Constant Flow Simulations
The Historical_constant_flow_.txt is composed of Historical Delft3D model output for the Morrison Bridge in Portland, OR from April 11, 2005 to August 11, 2005. Willamette River discharge is modeled from Oregon City, OR. The Columbia River is modeled from Bonneville OR. The water level data is meters relative to NAVD88 datum.

The Historical_constant_flow_02.txt is composed of Historical Delft3D model output for the Morrison Bridge in Portland, OR from April 11, 2005 to August 11, 2005. Willamette River discharge is modeled from Oregon City, OR. The Columbia River is modeled from Bonneville OR. The water level data is in meters relative to NAVD88 datum.

The Modern_constant_.txt is composed of Modern Delft3D model output for the Morrison Bridge in Portland, OR from April 11, 2005 to August 11, 2005. Willamette River discharge is modeled from Oregon City, OR. The Columbia River is modeled from Bonneville OR. The water level data is in meters relative to NAVD88 datum.

Each data description file contains the description of the first row container headers.

Data Description - Flood simulations
The Historical_flood_falling.txt contains output from the simulation of the 1880 Spring freshet. The data is composed of Historical Delft3D model output for the Lower Columbia Channel from 11:30 am July 7, 2005 to 12:30 pm July 8, 2005. The water level is for observation points at 5 km increments. Water level data is meters relative to the NAVD88 datum.

The Historical_flood_peak.txt contains output from the simulation of the 1880 Spring freshet. The data is composed of Historical Delft3D model output for the Lower Columbia Channel from 11:30 am June 2, 2005 to 12:30 pm June 3, 2005. The water level is for observation points at 5 km increments. Water level data is meters relative to the NAVD88 datum.

The Historical_flood_rising.txt contains output from the simulation of the 1880 Spring freshet. The data is composed of Historical Delft3D model output for the Lower Columbia Channel from 11:30 am April 23, 2005 to 12:30 pm April 24, 2005. The water level is for observation points at 5 km increments. Water level data is meters relative to the NAVD88 datum.

The Modern_flood_falling.txt contains output from the simulation of the 1880 Spring freshet. The data is composed of Modern Delft3D model output for the Lower Columbia Channel from 11:30 am July 7, 2005 to 12:20 pm July 8, 2005. The water level is for observation points at 5 km increments. Water level data is meters relative to the NAVD88 datum.

The Modern_flood_falling.txt contains output from the simulation of the 1880 Spring freshet. The data is composed of Modern Delft3D model output for the Lower Columbia Channel from 11:30 am June 2, 2005 to 12:20 pm June 3, 2005. The water level is for observation points at 5 km increments. Water level data is meters relative to the NAVD88 datum.

The Modern_flood_rising.txt contains output from the simulation of the 1880 Spring freshet. The data is composed of Modern Delft3D model output for the Lower Columbia Channel from 11:30 am April 23, 2005 to 12:20 pm April 24, 2005. The water level is for observation points at 5 km increments. Water level data is meters relative to the NAVD88 datum.

Each data description file contains the description of the first row container headers.

Data Description - Inundation
Historical Inundation
The Historical Inundation contains data for the 1880 Spring freshet on the Historical Delft3D model. The files contain X, Y, and Z coordinates needed to produce a contour plot of the peak inundation.

File: Historical_Da_X.xlsx
X coordinates in the D domain of the Historical model. The data is in meters on the Washington South state plane coordinate systems. Empty cells have the value -999.

File: Historical_Da_Y.xlsx
Y coordinates in the Da domain of the Historical model. The data is in meters on the Washington South state plane coordinate systems. Empty cells have the value -999.

File: Historical_Da_Z.xlsx
Water level elevation in the Da domain of the Historical model. The data is in meters on the NAVD88 datum.

File: Historical_Db_X.xlsx
X coordinates in the Db domain of the Historical model. The data is in meters on the Washington South state plane coordinate systems. Empty cells have the value -999.

File: Historical_Db_X.xlsx
Y coordinates in the Db domain of the Historical model. The data is in meters on the Washington South state plane coordinate systems. Empty cells have the value -999.

File: Historical_Db_Z.xlsx
Water level elevation in the Db domain of the Historical model. The data is in meters on the NAVD88 datum.

Modern Inundation
The Modern Inundation contains data for the 1880 freshet on the Historical model. The files contain X, Y, and Z coordinates needed to produce a contour plot of the peak inundation.

File: Modern_D_X.xlsx
X coordinates in the D domain of the Modern model. The data is in meters on the Washington South state plane coordinate systems. Empty cells have the value -999.

File: Modern_D_Y.xlsx
Y coordinates in the D domain of the Modern model. The data is in meters on the Washington South state plane coordinate systems. Empty cells have the value -999.

File: Modern_D_Z.xlsx
Water level elevation in the D domain of the Modern model. The data is in meters on the NAVD88 datum.

File: Modern_E_X.xlsx
X coordinates in the E domain of the Modern model. The data is in meters on the Washington South state plane coordinate systems. Empty cells have the value -999.

File: Modern_E_Y.xlsx
Y coordinates in the E domain of the Modern model. The data is in meters on the Washington South state plane coordinate systems. Empty cells have the value -999.

File: Modern_E_Z.xlsx
Water level elevation in the E domain of the Modern model. The data is in meters on the NAVD88 datum.

Each data description file contains the description of the first row container headers.

Data Description - Tidal Decay
The Historical_tiday_decay.txt is composed of Historical Delft3D model output for the Lower Columbia River from August 10, 1877 to October 18, 1877. The water level data is meters relative to the NAVD88 datum.

The Modern_tidal_decay.txt data is composed of Historical Delft3D model output the Lower Columbia River from July 31, 2005 to October 18, 2005. The water level data is meters relative to NAVD88 datum.

Each data description file contains the description of the first row container headers.

DOI

10.15760/cee-data.01

Persistent Identifier

https://archives.pdx.edu/ds/psu/29438

Constant_flow_data-and-description.zip (291 kB)
Constant Flow Data and Description

flood_simulations_data-and-descriptions.zip (179 kB)
Flood Simulations Data and Description

Inundation_data-and-description-files.zip (4295 kB)
Inundation Data and Description

tidal_decay-data-and-description.zip (532 kB)
Tidal Decay Data and Description

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