The NetMap concept is based on standardized, contiguous digital map databases that interact with a plug & play analysis tool library (erosion, stream temperature, in-stream wood etc.) to create customizable analysis platforms for decision support in a wide range of natural resource activities. Refer to the 2009 American Geophysical Union article on “the future of applied watershed science at regional scales” for additional information (available for download at the bottom of NetMap’s home page).
The uniform, contiguous and attributed stream map databases can be downloaded, and then adjusted with respect to locations of channel heads, drainage density and the length scales of stream networks (default stream segment length scale averages 100 m but is variable depending on along-stream variation in attributes such as channel gradient, width and valley width). The map database is attributed with information including segment ID, elevation, gradient, width, length, valley/floodplain width, and annual precipitation, among other information. In addition, users across the coverage area can rectify the map databases (adjust channel heads and drainage density, as well as adding drainage peculiarities such as diversions, artificial channels and dams) and upload the corrections back to the server (through a gate keeper). Thus, NetMap’s standardized stream layer provides more accuracy, functionality, and flexibility compared to the NHD (although it uses some of NHD’s attributes). In NetMap, information attributed in other GIS stream layers, including the NHD, can be transferred to the NetMap stream layer and vice versa, using tools within the NetMap system.
A uniform digital map database facilitates the ‘community’ nature of NetMap in that its partners, and other users, can build and upload analysis models and modules to the ‘tool library” for their use in building customizable tool (host) platforms. Community based also refers to the development of standardized stream (map) databases that are made available to everyone across the coverage area.
Features of NetMap:
- Uniform data structure. Channel segments (and tributary confluence nodes) are defined as are the spatial relationship between channel segments and hillsides via fine scale “drainage wings”. Channel heads and thus drainage density are calibrated to landscape attributes and will vary across diverse geographies. Users can adjust default channel heads and drainage densities (as well as the length scales of channel segments) and therefore stream networks can be rectified, including by adding drainage attributes such as diversions and dams. Rectified networks can be uploaded to the server to make the standard databases more accurate over time.
- Standardized, region-wide database. A large and expanding region-wide watershed database (see “watershed coverage”) allows users easy access to hundreds of watersheds for rapid, consistent analyses and to facilitate comparative analyses across landscapes, states and regions.
- Community based. As new watershed databases are developed and new tools are created, they become immediately available to all users. In addition, the community of partners and other users develop models and analysis modules that can be uploaded to the community tool library.
- Decision Support. NetMap can inform fish habitat management, forestry, pre- and post fire planning, restoration, conservation, climate change, monitoring, research and education.
- A new analysis paradigm and methods framework. In the context of “watershed analysis” (or basin assessments) analysis software tools are distributed with the analysis allowing stakeholders to conduct custom analyses as new questions arise, as new data becomes available (or as more accurate data becomes available), or as watershed conditions change (wildfires or land use activities).
- A “living analysis”. NetMap watershed databases do not become dated over time because ‘field link” tools allow rapid validation of predicted attributes and thus databases are made more accurate with use.
