NetMap's Technical Help Guide


Load) Data (load Digital Hydroscapes by map or name)
Parameter Description:  na
Data Type: Digital Hydroscape databases (also referred to as "digital watersheds" or simply as "datasets").
Name: Differentiated by Hydrologic Unit cWatershed name or code
Units: na
NetMap Module/Tool: Load Data in Master Tool Bar
Model Description:
In NetMap individual watersheds are selected and loaded. From the master tool bar, Click on "Load Data" and then Search from Map or Choose from List to locate watersheds of interest (Figure 1). A  watershed or group of watersheds in a single NetMap dataset will range in size from approximately 200,000 to 400,000 acres (300 –600 mi2, 800 – 1,600 km2). Watersheds are obtained from the data catalogue using the website ( (or can be snail mailed to clients).
Step 1: From the NetMap tool bar, click on "Load Data" - options include (1) List Datasets or (2) Load Data from Map. Note the "NetMap Environmental Settings"; refer to either "Get Started" or the "Environmental Settings" Help. Selecting from the list opens another interface (3) from which a drop down list of NetMap datasets is displayed, indexing the datasets (4) located on a users hard drive.
If a user would like to select from Hydrologic Unit Code watershed names or if a user is associated with the US Forest Service, National Forest System then (5) is selected. See Step 2.
Step 2. The pop up box will provide two options: 1) Use a series of watershed scales (Hydrologic Unit Codes Level 1 - 4 [e.g., 2 to 8 digit]) and agency jurisdictions (US Forest Service, Regions, Forests and Districts).
For users working with only one or a few datasets, Option 2 is the quickest.
Step 2 (Option A): Watersheds (Hydrologic Unit Code):
(A) Using Hydrologic Unit Code watersheds Levels 1 through 4. (A) First, select HUC Level 1 (Alaska versus Pacific Northwest, (B-C), Next, select HUC Level 2 and (D) Level 3, and finally HUC Level 4 (E), which is the NetMap dataset level. The drop down will show all included HUC 4 names, those with asterisks (*) will be on your hard drive.
Step 2 (Option B):
Agency Jurisdictions (US Forest Service): (A) Using National Forest jurisdiction, select a Region (B-C) and then a Forest (D).
Then select a district (E-F). All relevant NetMap datasets will be listed in the drop down (F). Only those you have on your hard drive will show up with an asterisk (*).
Then simply select the right dataset and load in ArcMap.
Once loaded, one should define a fish distribution. NetMap differentiates channel networks into fish bearing and non-fish bearing streams. This is primarily for the purpose of map display where a user may only wish to display, for example, channel gradients on larger fish-bearing streams, or where a user may wish to conduct an analysis (such as calculating drainage density) only on fish bearing channels. Because of the dominance of small first- and second-order headwater channels in a watershed, the overall proportion of fish bearing channels may be small (40% or less).
Using the Map Option.
Choose "Load Data from Map". A map pops up showing all existing NetMap HUC 4 datasets (Digital Hydroscapes). Running your cursor over the map will identify the name of the HUC watershed. Green colored NetMap datasets are those located on a users hard drive. The red colored datasets have yet to be downloaded from our website. Clicking on the dataset loads in into ArcMap.

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