Navigating the Network: Part 3

Find upstream accumulation of an invasive species

 

The city of Dillon is performing a risk assessment to understand the potential upstream impact the Zebra Mussel, an invasive species, would have if it were discovered in Dillon Reservoir.

 

As the GIS Analyst for the city of Dillon, you have been tasked with calculating the total miles of StreamRiver that could be impacted by Zebra Mussels in Dillon Reservoir.  

 

Go to the Dillon Reservoir bookmark.

 

In the Utility Network Analyst toolbar, change the Trace Task to “Find Upstream Accumulation”.

 

Place an edge flag on the Artificial Path feature just before it exits the reservoir.

 

Click on the solve button  to execute the trace.

 

Note: Since you changed the Results Format to be a selection in exercise 1, the features will be selected rather than highlighted.

 

Go to the Invasive Species Impact Bookmark to see the impacted area upstream of Dillon Reservoir.

 

You can see that the potentially impacted area is very large. Calculate the total length of stream that could be impacted for your risk assessment report.

 

Open the NHDFlowline Feature Class attribute table.

 

Choose the option to view only selected features.

 

Drag the scroll bar until you see the Length_KM Field.

 

Right click on the field and choose “Statistics”.

 

 

Provide feedback on this tutorial: Email krisham@usgs.gov

 

What tutorial would you like to see next?