Introduction to DSAS v5.0: Sample Data Workflow

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Detailed Description

This video demonstrates use of the Digital Shoreline Analysis System (DSAS) v5.0 to produce rates of shoreline change. For more information please visit the DSAS project page: https://woodshole.er.usgs.gov/project-pages/DSAS/ 

The Digital Shoreline Analysis System (DSAS) is a freely available software application that works within the Esri Geographic Information System (ArcGIS) software to compute rate-of-change statistics for a time series of shoreline data. DSAS provides an automated method for establishing measurement locations, performs rate calculations, provides the statistical data necessary to assess the robustness of the rates, and includes a beta model of shoreline forecasting. 

DSAS version 5.0 (v5.0) was released in December 2018 and has been tested for compatibility with ArcGIS versions 10.4 and 10.5. It is supported on Windows 7 and Windows 10 operating systems. If you use it, please cite it as follows and note the current version:
Himmelstoss, E.A., Farris, A.S., Henderson, R.E., Kratzmann, M.G., Ergul, Ayhan, Zhang, Ouya, Zichichi, J.L., Thieler, E. R., 2018, Digital Shoreline Analysis System (version 5.0): U.S. Geological Survey software release, https://code.usgs.gov/cch/dsas.

Details

Image Dimensions: 854 x 480

Date Taken:

Length: 00:06:32

Location Taken: Woods Hole, MA, US

Video Credits

Audio voice over by Meredith Kratzmann (USGS)

Transcript

Hello and welcome to the USGS series of help videos for the Digital Shoreline Analysis

System, or DSAS.

Today we present "Introduction to DSAS v5.0: Sample Data Workflow."

This workflow assumes that you have already installed DSAS v5.0 with an ArcMap version of

of 10.4 or higher, and have downloaded the USGS provided sample data.

If not, please use the links listed below this video to navigate to the DSAS project page,

where instructions on installing DSAS and downloading sample data can be found.

Before getting started with DSAS, please make a note of the available help resources.

In each DSAS window, there are gray "help" question marks. Simply click the question mark

to read more about each element. For additional questions navigate to

"DSAS Help", where you will find links to the DSAS Project Page and the full DSAS v5.0 User Guide.

To begin, open ArcMap and click the “add data” button.

Navigate to the folder where the DSAS sample data have been saved.

Select both the shoreline and
baseline data and add them to the map.

If you like, double click on each file in the table of contents to adjust the color properties.

Next we will add a basemap file by clicking the drop-down arrow next to the “add data”

button. Choose “add basemap” and select Imagery. Now we can orient the shoreline and

baseline data in reference to land.

Next locate the DSAS toolbar - and click the “Default Parameters” button.

Select the baseline by clicking the drop-down arrow in “Baseline Layer” then choose

the basic baseline. Select the "Baseline ID Field" - ID

Leave the "Baseline Group Field" and the "Baseline Search Distance Field" blank.

To determine the loation of land relative to baseline orientation check the box next to

"Show Baseline Orientation.” This will change the symbology of the baseline layer to indicate

the direction of flow of the baseline. This will help you make sure that all baseline segments

are flowing in the same direction and allow you to determine the location of land relative to

baseline orientation. The land is oriented to the right of the baseline in this case.

For baseline placement, choose the “Midshore (or combination)” option, as the baseline

segments are located both onshore and offshore.

Next, click on the "Shoreline Settings"
tab.

Choose the shorelines by clicking the drop-down arrow in “Shoreline Layer’ and select

the basic shorelines. Next, select the "Date Field" -  “DSAS_date” and choose

“DSAS_Uncy” for the "Shoreline Uncertainty Field".  Keep the default uncertainty set to 10

meters. For "Intersection Parameters", select “Seaward Intersection”

Next click on the "Metadata Settings" tab.

For this section, populate the fields with general information to assist in automatic

metadata production. Each element is required so be sure to fill in all the blanks!

This may take a few minutes, but only needs to be done once.

When you have finished - click OK to save all default parameter settings.

Next, locate the DSAS toolbar and click the “Cast Transects” button.

By default DSAS will save the transects and all subsequent rate information to the same

geodatabase as the baselines and shorelines. Provide a name for the  new transects.

Set the value for Maximum search distance to 1000, this will be the distance that

DSAS searches on either side of the baseline for transects.

Next set the transect spacing to 100 meters and set the smoothing distance to

1000 meters. Keep the default setting to clip transects to shoreline extent and click

OK to cast transects.

A DSAS Alert will appear to inform you that the new transect layer has been selected

in the DSAS toolbar, which is required for editing and calculating shoreline change rates.

If you like, double click on the transect file to change its color properties.

Review the transect coverage to ensure all shorelines are intersected and the

orientation of the transects is roughly perpendicular to the general shoreline trend.

From the DSAS toolbar click the “Calculate Rates” button.

Select the statistics to run. You can choose “all” by clicking the checkbox at the top,

or select individual statistics. For "Additional Parameters" - keep the default settings for

"Intersection Threshold" and "Confidence Interval". For "Outputs" - choose to display the

results using a color ramp by clicking the drop-down arrow and selecting the "LRR" statistic.

Choose “Create DSAS Summary Report” which will summarize all of the basic statistics

in a text file which is saved to the folder that contains the shoreline and baseline

geodatabase. Click calculate to start. This may take a few minutes.

Once DSAS has finished running, close the dialog box and review the newly created

transect and intersect shapefiles.

New to DSAS v5.0, rate information is stored with the transect file. If selected in the

rate calculation settings, rates are returned with a predefined color ramp based on the

selected statistic. In addition, all shoreline intersection  information is now stored in a

new point shapefile.

Once you have run rates, you can easily change the way the rate transects appear in

the map. From the DSAS toolbar, click the “Data Visualization” button.

Choose a rate layer within the map and select the desired statistic to display.

Options for displaying rates include  “Apply color ramp” (a standardized color ramp

Options for displaying rates include  “Apply color ramp” - a standardized color ramp

designed by the USGS - or “scale to my data” - where output is adjusted to the full range

of rate values within the dataset.

This concludes the demonstration of the USGS provided basic sample data set for

DSAS v5.0.

You can view other DSAS help videos at the DSAS Project page listed below this video.