4 Conducting the FRA
Last updated
Last updated
The tool requires inputs for 17 parameters, with four optional parameters. The parameters are separated into seven categories. Each parameter will be described in further detail below. Additionally, if you are using the example data provided with the toolbox, for each parameter a suggested input will be recommended to provide a tutorial for using the tool.
This parameter allows users to quickly populate the parameters for the tool using a “config.xls” file that was created in the results folder of a previous execution of the tool (Figure 4.1). If an excel file is input into the parameter, the file is parsed to extract the values for the parameters of the tool. If there are any issues in reading the parameters from the excel file, an error message is displayed. Parameters that are unaffected by the error will be populated, but the parameters that encountered the error will need to be specified manually or corrected in the excel file and loaded again. If you are using the example data, navigate to the data folder provided in the extracted zip folder and select the “tutorial_config.xls” file. Alternatively, the parameters of the tool can be specified manually following the instructions provided with each parameter below. If you are using the “tutorial_config.xls”, the path settings (the file paths to the data) will need to be specified manually, all other settings will be populated automatically.
This button allows users to apply default settings to all the tool’s parameters. This is the fastest option for running the tool. The example data provided with the tool will be used as the default data. Note that for the default settings to load the required Path Settings, the folder structure will need to be consistent with the structure provided in the zip folder (see ZIP Folder Contents). The user can modify any of the loaded parameter settings if they would like to make adjusts before running the analysis.
This parameter allows users to select whether to run a full set of calculations or a subset of the available calculations (Figure 4.2). Click the buttons next to DOF, DOR, SED, or CSI to select the desired options. For the tool to run, at least one run option must be selected. If you are using the example data, select all four options.
Five file paths are required for the tool to run (Figure 4.3). For each required path, navigate to the corresponding data through the browse folder button and select it. If you are using the example data, select the browse folder button and navigate to the folder where the example data was extracted from the zip folder.
General settings include parameters that affect multiple calculations (Figure 4.4). For the barrier/dam inclusion field, use the drop down to select the field that is used to indicate which dams are included in the assessment from the “Barrier feature class” that was specified in the “Path Settings”. Values for this field should be 0 or 1. A value of 1 or 0 indicates to use or not to use the barrier, respectively. If you are using the example data, select the field: INC.
Update/Overwrite stream table parameter specifies if the newly calculated values for DOF, DOR, and SED should replace the current values in the corresponding fields (the fields specified in the Degree of Fragmentation Settings, Degree of Regulation Settings, and Sediment Trapping Index Settings). If you are using the example data, select “YES”.
Minimum length threshold is used to excluded small backbone rivers from the calculations. The minimum length threshold is in units of kilometers. Rivers with a length less than or equal to the specified threshold value are excluded, while rivers above the threshold value are included. If you are using the example data, input 100.
There are six Degree of Fragmentation Settings, but only four need to be specified (Figure 4.5). The degree of Fragmentation field is used for storing the calculated degree of fragmentation values. Use the drop down to select the desired field from the “Streams feature class” that was specified in the path settings. If you are using the example data, select the field: DOF.
The “use dam level discharge factors” parameter is used to select whether static or dam specific discharge range factors are used in the DOF calculations. From the dropdown, select “YES” or “NO”. The four parameters below “use dam level discharge factors” are disabled until an option is selected, after which the required parameters associated with the parameter selection will become enabled. If “NO” is selected, the algorithm applies static upstream and downstream discharge range factor values to all dams included in the calculations. The “Upstream Discharge Range Factor” and “Downstream Discharge Range Factor” parameters become enabled and are required if “NO” is selected. If “YES” is selected, the algorithm uses the values from the fields specified in the “Dam Level Upstream Discharge Factor Field” and “Dam Level Downstream Discharge Factor Field” parameters to calculate dam-specific DOF results. The “Dam Level Upstream Discharge Factor Field” and “Dam Level Downstream Discharge Factor Field” become enabled and required if “YES” is selected. If you are using the example data, select "NO".
For the “Upstream Discharge Range Factor” and “Downstream Discharge Range Factor” parameters, the value is pre-populated as 5. You can either leave the value as the default of 5 or input a new number to be used for the discharge range factor value. The number must be greater than or equal to 1. A discharge range factor of 1 signifies that there is no effect. There is no upper limit, but a value larger than 10 is not recommended. The standard value is 5, which means that the DOF effect occurs in river reaches with up to five times larger or smaller from the location of the dam. Please review the methodology section of the research article (Grill et al., 2018) for further details. If you are using the example data, leave the value as the default value of 5.
For the “Dam Level Upstream Discharge Factor Field” and “Dam Level Downstream Discharge Factor Field”, select the desired fields from the dropdowns containing the discharge range factor values for each dam. The fields provided in the dropdown are the fields available in the “Barrier Feature Class” that was specified in the Path Settings. If using the Dam level Discharge Range Factors with the example data, two example fields are provided: drf_up and drf_dwn, respectively. The values provided in these fields were created as random integer values and are for demonstrative purposes only.
These two parameters are specific to the Degree of Regulation calculations (Figure 4.6). The Degree of Regulation Field is used for storing the calculated degree of regulation values. Use the dropdown to select the desired field from the “Streams feature class” that was specified in the Path Settings. If you are using the example data, select the field: DOR.
For the “Source Field for Reservoir Storage Volume”, use the dropdown to select the desired field from the “Barriers feature class” that was specified in the Path Settings. The values of this field indicate the storage volume for each dam (Note: units must be in million cubic meters). Please review the methodology section of the research article (Grill et al., 2018) for further details on how reservoir storage volume is incorporated into the degree of regulation calculations. If you are using the example data, select the field: STOR_MCM.
The Sediment Trapping Index Field is used for storing the calculated sediment trapping index values (Figure 4.7). Use the dropdown to select the desired field from the “Streams feature class” that was specified in the Path Settings. If you are using the example data, select the field: SED.
The scenario settings allow users to define individual scenarios for calculating CSI (Figure 4.8). If the “tutorial_config.xls” file was used in the “Auto-populate parameters using config excel sheet (optional)” parameter, an example scenario called “tutorial” is provided. Typing a name into the parameter “Scenario Name” adds a new scenario to the table. The name provided must be under 10 characters, cannot have spaces or special characters, and cannot start with a number or underscore. It is recommended to use simple names, something like “CSI01”.
Once a scenario has been added to the table, the remaining columns of the scenario must be completed. For the indicator columns, select a field from the dropdown that contains values for the corresponding indicator. The fields provided in the dropdown are from the fields in the “Streams feature class” that was specified in the Path Settings.
The weight columns are used to apply a weighting to the corresponding indicator. Input values ranging from 0 – 100. However, the sum of the six weights must equal 100. The CSI threshold is used for determining the Free-Flowing river status. Values for CSI threshold must be greater than zero and less than or equal to 100%. The “Flood Plain Damp” parameter (fld_damp) determines the strength of the floodplain weighting, which interacts with the RDD and URB pressure indicators. See the methodology section of the research article (Grill et al., 2018) for further details. Values for Flood Plain Damp can range from 0 to 100. The “Filter Threshold” scenario setting is used for filtering extreme outliers. Values for “Filter Threshold” can range from 0 to 100. Filter Threshold is considered an advanced parameter. It is recommended to set the filter threshold to 0.1. The “To Process” scenario setting determines whether the scenario will be processed when the tool is executed. From the drop down, select “Yes” if the scenario should be processed when the tool is run or “NO” to skip the scenario when the tool is run. The “To Export” scenario setting determines if a results table, feature class, and ArcMap document will be created for the scenario in the output folder. From the dropdown, select “YES” to create the files and select “NO” to skip creating the files. If you are using the example data, select the options displayed in Figure 4.8.
When all the parameters have been populated, click the “OK” button at the bottom of the tool window (Figure 4.9a). If no errors are encountered with the parameters, the tool will start conducting the analysis and the tool dialog window will appear (Figure 4.9b). It is recommended to have the “close this dialog when completed successfully” unchecked so that the messages in the dialog window can be reviewed after the tool has finished running. The dialog window provides messages during the execution of the tool regarding the progression of the tool and information about the analysis (Figure 4.9c). When finished the dialog window will say “succeeded” followed by the date and the elapsed time for the tool to run (Figure 4.9d). The results excel file and an ArcMap document displaying the spatial results will automatically open.
