Data and code for: "Predicting head loss and hydraulic roughness of channel-spanning large wood jams"
Data files
May 15, 2026 version files 65.73 KB
-
Data_to_Mannings_n_Combined_Ljam.xlsx
7.88 KB
-
EquationApplication.py
5.30 KB
-
Field_Data.xlsx
9.15 KB
-
Field_Data2.xlsx
8.71 KB
-
Non-linear_Model_1.26.26.py
6.83 KB
-
README.md
5.41 KB
-
Roughness_Calculation_Verification.py
6.58 KB
-
survey_data.xlsx
15.87 KB
Abstract
Log jams enhance hydraulic and geomorphic diversity in river corridors. Channel-spanning log jams induce backwatering while also increasing local flow heterogeneity, promoting sediment deposition, and improving aquatic habitat diversity. Recognizing the benefits of log jams, river scientists, managers, and engineers are increasingly adding jams to restoration projects with little guidance on predicting the hydraulic effects of jams. Understanding and predicting the head loss induced by log jams in natural systems with variable channel dimensions requires an alternative approach to a traditional backwater calculation. We paired historical flume studies and field data from natural log jams to develop and evaluate a model to predict dimensionless head loss through jams for sub-bankfull flows. As solid volume fraction increased, we found that dimensionless head loss also increased. Field application of our model successfully predicted head loss in naturally occurring log jams. Using field-verified head loss values, we calculated Darcy-Weisbach friction factor and Manning’s roughness coefficients for a range of unit discharges. Roughness values varied but generally decreased with increased unit discharge. Our approach for determining head loss and roughness allows for better prediction and design of the localized hydraulic impacts of log jams.
Dataset DOI: 10.5061/dryad.d7wm37qf7
Description of the data and file structure
Traditional backwater methods are limited in variable natural channels, so we developed a model to predict dimensionless head loss through log jams for sub-bankfull flows. We developed the model from historical flume studies and tested the model application on field data from natural jams.
Files and variables
File: Non-linear_Model_1.26.26.py
Description: Python script used to develop and evaluate field utility of non-linear dimensionless head loss model using input files of "Combined_Standard_Step_Results.xlsx" ; "Field_Data.xlsx" ; "Field_Data2.xlsx" .
1. Univariate log-log regressions for parameter evaluation
2. Runs non-linear model fit for a prediction of the non-dimensional headloss through the jam
3. Performs 10-fold cross-validation for model performance evaluation
4. Plots field and model results on single plot
File: Roughness_Calculation_Verification.py
Description: Python script used to do the following with the input file of "Data_to_Mannings_n_Combined_Ljam.xlsx".
1. Calculates Manning’s n and Darcy-Weisbach friction factor from experimental flume data
2. Computes backwater profiles via the standard step method.
3. Outputs a results table ready for nonlinear model fitting ("Combined_Standard_Step_Results.xlsx")
File: Data_to_Mannings_n_Combined_Ljam.xlsx
Description: Base file used for input into Roughness_Calculation_Verification. Note, only headers were provided for this datafile as the input data for the associated study utilized data from Schalko (2018) and Follett (2020), which are under a CC by 4.0 license.
Variables
Note column name may be in parentheses () and units are in brackets [] unless dimensionless.
We describe the input columns from the related works/datasets of Schalko (2018) and Follett (2020) that were used to develop the complete input file of Data_to_Mannings_n_Combined_Ljam.xlsx
- Input columns derived from Schalko (2018) and Follett (2020):
- Source Dataset: Schalko, Follett
- Test No.
- Follett dataset: Test No.
- Schalko dataset: Test Series JHE
- Flume width (B) [m]
- Follett dataset: B (m)
- Schalko dataset: Channel Width B
- Discharge (Qcms) [m^3^/s]
- Follett dataset: Q (m3/s)
- Schalko dataset: Discharge Q
- Jam length (L) [m]
- Follett dataset: L (m)
- Schalko dataset: Accumulation Length La
- Upstream and Downstream depth (h1, h2) [m]
- Follett dataset: H1 (m), H2 (m)
- Schalko dataset: Backwater rise ∆h, Approach flow depth
- h1 = Backwater rise + Approach flow depth
- h2 = Approach flow depth
- Calculated variables: area (A1, A2) [m^2^], velocity (U1, U2) [m/s], wetted perimeter (P1, P2) [m], hydraulic radius (R1, R2) [m], and jam solid volume fraction (SVF)
- Channel geometry equations based off a rectangular channel were used for area, wetted perimeter, hydraulic radius.
- Velocity was determined from area and discharge.
- SVF calculations:
- Follett: SVF remained constant
- Schalko: Calculated SVF from Solid LW volume Vs, Loose LW volume Vl, and Vol% Organic Fine Material FM
File: Field_Data.xlsx
Description: Data from field measurements for application in the model for upstream and downstream Goat Creek, Monture Creek, Little Beaver Creek.
Variables
Note column name may be in parentheses () and units are in brackets [] unless dimensionless.
- Site name, Froude ratio (Fr2/Fr1), jam solid volume fraction (SVF), head loss (H1-H2), Manning's n [s/m^1/3^], Darcy Weisbach f
File: Field_Data2.xlsx
Description: Data from field measurements for application in the model for Lost Creek.
Variables
Note column name may be in parentheses () and units are in brackets [] unless dimensionless.
- Site name, Froude ratio (Fr2/Fr1), jam solid volume fraction (SVF), head loss (H1-H2), Manning's n [s/m^1/3^], Darcy Weisbach f
File: survey_data.xlsx
Description: Example input file for EquationApplication.py. Uses survey and discharge data from Goat Creek (MT), it is referenced as "Lower Goat" in the associated manuscript. Note the file corresponds to only one discharge and one solid volume fraction and thus columns Q and SVF only have one listed value.
Variables
Note column name may be in parentheses () and units are in brackets [].
- Section (Upstream/Downstream), Easting [m], Northing [m], Elevation [m], Type (bed/water), Discharge (Q) [m^3^/s], Solid Volume Fraction (SVF)
File: EquationApplication.py
Description: Python code to calculate a predicted upstream depth and energy head from upstream/downstream channel surveys, downstream water depth, jam solid volume fraction, and discharge.
- Loads survey data from survey_data.xlsx workbook
- Calculates downstream geometry using given water elevation
- Uses equation and upstream channel geometry to predict upstream water surface elevation and energy head
- Plots both upstream and downstream channel geometry and predicted water surface elevations
Code/software
Python version 3.12.4
Python packages: numpy, pandas, scipy, scikit-learn, matplotlib, openpyxl
