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Step 4: Create and Calculate an Analysis

Time: ~5 minutes

Now you'll use the DCEs and sample frames to create something new: an analysis calculating Dam Density.

Create the analysis

  1. In the QRiS Project Explorer, right-click Analyses.
  2. Choose Create New Analysis.
  3. Enter the settings below.
SettingChoose
NameQuickstart Analysis
Analysis Mask / Sample FrameSF
Valley BottomValley Bottom
CenterlineCL
DEMLeave blank

Choose one metric

QRiS can calculate many different riverscape metrics. For this quickstart, you'll use just one.

Under the Metrics and Indicators tab, expand the LTPBR Protocol metric list:

  1. Leave the metrics set to None by default.
  2. Find Dam Density.
  3. Under Usage, change None to Metric.

Dam Density measures the number of dams per unit length of riverscape.

Choose your data capture events

By default, all available data capture events are included. We will limit our analysis to the two DCEs we already explored.

Under the Data Capture Events tab:

  1. Click Select None.
  2. Select only October 2021 Pre Project and November 2021 Implementation.
  3. Click OK to create the analysis.

Calculate the metric

Your new Quickstart Analysis should now be open.

  1. Click Calculate....
  2. For Data Capture Events, choose All data capture events.
  3. For Sample Frames, choose All Sample Frames.
  4. Leave the remaining options as-is.
  5. Click OK.

QRiS will calculate Dam Density for each sample frame and data capture event that contains observations applicable to the chosen metric, Dam Density.

Compare the two DCEs

Let's return to the two data capture events you looked at in Step 2. Use the dropdowns in the analysis window to:

  1. Set Mask Polygon: to 2
  2. Set Data Capture Event: to October 2021 Pre Project
  3. Note the Dam Density value.
  4. Change only the Data Capture Event to November 2021 Implementation.

Watch the Dam Density value change.

Earlier you saw the observations change on the map. Now QRiS has turned that difference into a comparable metric.

What to know

An analysis connects three pieces of the project:

  • observations through time (DCEs),
  • a defined measurement area (sample frame),
  • a defined metric (Dam Density).

QRiS calculates the metric consistently across the monitoring record.