NetMap's Virtual Watersheds & Smart River Networks provide
decision support in resource management, risk mitigation, restoration and conservation.
A ‘virtual watershed’ is a computer-aided geospatial simulation of riverine landscapes used to enumerate numerous aspects of watershed landforms and processes, and human interactions within them over a range of scales.
A Virtual Watershed includes synthetic river networks and the highest resolution digital elevation models, couples them together, and then adds five types of analytical capabilities, including:
1) routing information downstream and upstream,
2) connecting river networks to terrestrial environments,
3) discretizing landscapes and land uses into facets of appropriate scales to identify interactions,
4) characterizing landforms and
5) attributing river segments with key stream and watershed information.
They are customizable and adaptable to specific needs.
It is important to note the distinction between stand-alone hydrography or stream layers (cartographic or synthetic) and a Virtual Watershed (a system of hydrography, coupled to DEMs, which include the five analytical capabilities listed above).
Complete and accurate hydrography, including using standard models (such as ArcHydro [Maidment 2002], TauDEM [Tarboton 1997] and HEC-GeoHMS [USACE 2000]) may include a subset of the analytical capabilities listed above or none of them. In addition, the NHD/NHDPlus does not contain the flexibility or analytical capabilities of NetMap's virtual watershed (to learn more, learn about the NHDPlus and national-scale stream layers in other countries here). NetMap's virtual watershed can cross talk to the NHD, and vice-a-versa, for value added to both systems.
Hydrography that is coupled to a DEM, inclusive of the five analytical capabilities, is most appropriately thought of as a complete, integrated (terrestrial – fluvial) system with a numerical data structure that is designed to simulate various watershed processes and human interactions and thus to support resource management, risk mitigation and conservation.
NetMap's flexible Virtual Watershed is designed to address aquatic oriented resource management and conservation questions and to broaden access of those capabilities to larger stakeholder groups in a community setting (Miller 2003, Miller et al. 2003, Benda et al. 2007, Clarke et al. 2008, Miller and Burnett et al. 2007, 2008, Benda et al. 2011, Penas et al. 2011, Barquin et al. 2011, McCleary et al. 2011, Fernandez et al. 2012a, Pickard 2013, Ji et al. 2013, Bidlack et al. 2014, Reeves et al. in press, Barquin et al. in press).
The synthetic river network in a Virtual Watershed is the integrating feature, just like in real watersheds, and it supports analyses of connectivity and routing including: 1) downstream, 2) upstream, 3) across valley, 4) downslope - upslope, 5) terrestrial - river and 6) land surface - atmosphere.
In the Virtual Watershed, past, present and future land uses can be placed in context with natural processes and landforms to identify habitat stressor interactions and to optimize resource use, risk mitigation, restoration and conservation planning.
See Paper submitted for publication "Building Virtual Watersheds: A Global Opportunity to
Strengthen Resource Management and Conservation"
Learn how virtual watersheds are built (step by step, through a PPT)
Relationship between Virtual Watersheds and NetMap
Virtual watersheds or hydroscapes stand alone in concept and design architecture. The hydroscape's benchmark set of five elements is integrated within the NetMap
Decision Support System consisting of the unique combination of consistent
watershed datasets (e.g., digital hydroscapes), community based analysis tools,
online technical help and its bottom up sustainability via users licenses.