Lesson 15b: NHDPlus HR

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Detailed Description

This lesson will provide a brief overview of the National Hydrography Dataset, Watershed Boundary Dataset and 3D Elevation program. This lesson will also discuss NHDPlus and introduce NHDPlus high resolution and tell you how to get the data.
 

Details

Image Dimensions: 1919 x 1080

Date Taken:

Length: 00:12:26

Location Taken: Augusta, ME, US

Transcript

The National Map is a collection of mapping products and services produced by the USGS National Geospatial Program.   The products and services are accessed via the internet through service calls and graphical user interfaces.  The National Geospatial Program has released a series of “how to” videos for people who are working with The National Map data and services.  The videos show how to use the services and interfaces to access data and tools for viewing, analyzing and printing geospatial data.   The training materials are a mixture of video and PowerPoint-based lessons.  Lessons 1 and 2 serve as an introduction to the training materials.  The remaining lessons are designed as quick “how to’s” and may be viewed as needed, in any order, depending on the user.

Lesson 15b -  An Introduction to NHDPlus High Resolution

This lesson will provide a brief overview of the National Hydrography Dataset, Watershed Boundary Dataset and 3D Elevation program. This lesson will also discuss NHDPlus and introduce NHDPlus high resolution and tell you how to get the data.

The National Hydrography Dataset (NHD) and Watershed Boundary Dataset (WBD) are digital geospatial datasets that map the surface waters of the United States.  They are part of The National Map.  

The NHD and WBD are combined with elevation data from the 3D Elevation Program, or 3DEP, to create NHDPlus and NHDPlus high resolution. 

To start, let’s discuss each of these NHDPlus HR ingredient datasets.

The NHD represents the nation’s surface water drainage network and related features.  These features include rivers, streams, canals, lakes, ponds, glaciers, coastlines, dams, and stream gages. Although other scales are available, the NHD High Resolution, at 1:24,000 scale or better, is the most up-to-date and detailed hydrography dataset for the nation.

Characteristics of the NHD include:

Flow direction

The ability to navigate up and down the network from any point on the network

A stream address system based on from and to nodes

Which supports linear referencing or “addressing” of data events

Such as streamgages

which adds geospatial context to the streamflow data and enables a range of applications.

Visit the national hydrography dataset page for more information. 

The URL for this site is usgs.gov/NatHydroNHD

WBD serves as a seamless collection of nested hydrologic units for the nation. This illustration helps demonstrate its multi-level hierarchical structure. The larges hydrologic units are identified by a two-digit code. This is called the hydrologic unit code or HUC. These large units are divided into a collection of smaller hydrologic units. These smaller divisions gain an additional two digits on their HUC code. Each subsequent subdivision adds a progressive two-digit code. There are six required subdivision levels within the WBD. The smallest required unit has a twelve-digit code. WBD is complete for the nation to the twelve-digit hydrologic unit code with provisions for a fourteen and sixteen-digit delineations.

The surface water network and hydrologic units are fully integrated in the National Hydrography Dataset. 

Land elevation and the characteristics of the NHD and the WBD are closely related. 

Accurate and precise elevation data are important in improving the mapping of both, and the US Geologic Survey 3D Elevation Program continues to meet the growing needs for high quality topographic data for this purpose and others.  

More information about the USGS’s 3D Elevation Program can be found at

usgs.gov/core-science-systems/ngp/3dep

Accurate and precise elevation data is the third ingredient for the NHDPlus high resolution dataset.

The Environmental Protection Agency and USGS water programs developed NHDPlus to provide flow volume and velocity estimates along the NHD stream network to support dilution modeling for pollutants in the water.

To provide flow volume and velocity, the national hydrograph dataset, the watershed boundary dataset and elevation from the 3DEP program were integrated to create NHDPlus.

To produce NHDPlus, the elevation data needs to be modified to reflect the geographic locations of features in the current NHD and WBD datasets.  The elevation data are modified in the vicinity of the flow paths of NHD streams and the ridgelines of WBD hydrologic unit boundaries to make the three datasets consistent. 

Much of this processing will not be necessary when all three datasets are derived from 3DEP.

The resulting hydrologically-conformed elevation data (shown in Figure 1, on the left side) is then used to delineate catchments (local drainage areas) that conform to the streams and hydrologic units (shown in Figure 2, on the right side).

The catchments (which are shown with the yellow boundaries on the map) tie the landscape to the stream network (shown in blue) forming a ‘surface water geofabric’ for organizing and analyzing water resource information. This Geospatial Hydrologic Framework enables landscape attributes that have been allocated to a catchment to be associated with the local stream segment within the catchment. For example, it enabled precipitation and temperature data to be associated with the network for purposes of modeling stream flow volume and velocity.

NHDPlus is a suite of geospatial products that includes:

Complete snapshots of the primary ingredient data layers, as just described.

New stream attributes including flow volume and velocity estimates and a variety of so-called Value Added Attributes used to enhance display, allow rapid traversal of the stream network, and support modeling. Also included, are the set of USGS stream gages linked to the NHDPlus network and used in estimating flow volume and velocity.

Catchment and catchment attributes including the precipitation and temperature used for estimating flows as well as NLCD land cover.

The flow direction and accumulation grids produced to support the catchment delineation process.

The vector components of NHDPlus are available in Shapefile/DBF and File GeoDatabase formats, and the raster components in Grid format.

More information about NHDplus can be found at www.epa.gov/waterdata/nhdplus-national-hydrography-dataset-plus

Next we will discuss the NHDPlus High Resolution.  It is very similar structurally to the NHDPlus Version 2, for which a great deal of documentation is available. While not all aspects of the data are identical, nearly all concepts are applicable to the NHDPlus HR.  See the “Learn More” link… and clicking Documentation on the ‘Learn More’ page will take you to the relevant links.

The Hydrography Requirements and Benefits Study found that approximately 80% of users need the functionality of NHDPlus, but at a higher resolution.  USGS is building NHDPlus HR from the highest available resolution NHD and WBD data, and 10m DEM’s from 3DEP, much of which is now being derived from high resolution lidar data.

The results are more accurate, and the data used to make NHDPlus HR are actively maintained with the assistance of local authoritative sources.  NHDPlus HR also has multi-scale representation capabilities with the new Visibility Filter attribute.  This simplifies maintenance by limiting the number of hydrography layers that need to be maintained.

NHDPlus HR consists of vector and raster data layers. It includes a snapshot of the NHD and WBD at the time the NHDPlus HR was built, as well as the following components:

An elevation-based catchment area for each flowline in the stream network

Catchment characteristics, including mean annual precipitation, mean annual temperature, and mean annual runoff, and mean latitude

Cumulative drainage area characteristics

Mean annual flow (1971-2000) and velocity estimates for each flowline in the stream network

Flow direction, flow accumulation, elevation, and hydro-enforced elevation rasters

Headwater node areas

Flowline min/max elevations and slopes

In addition a set of value added attributes are included that enhance stream network navigation, analysis and display.

This table contrasts the characteristics of NHDPlus with NHDPlus high resolution.  For example, NHDPlus HR has almost 10 times as many hydrographic features than NHDPlus.  The average catchment size for NHDPlus HR is approximately 0.2 square miles versus 1.2 square miles in NHDPlus. 

More information about NHDPlus and NHDPlus High Resolution can be found at usgs.gov/NatHydroNHDPlus-HR

Scroll to the How can I learn more about NHDPlus HR.  It’s the last section on this page.

A poster of the NHDPlus Data Model v1.0 is available with details on dataset structure, feature classes, domains, and relationships.

An NHDPlus HR Data Dictionary is also available.  A full description of the value added attributes is provided.

In addition, a series of video presentations from a July 2016 workshop on NHDPlus Version 2 is available from the California Department of Water Resources. 

You can download NHDPlus HR products and access services by clicking on the ‘Access National Hydrography Products’ or by going to usgs.gov/NatHydroAccess.

NHDPlus HR can be accessed through the National Map download viewer.

Direct links to the data are provided.

Finally USGS also provides web services for basemap and hydrography datasets.

In this lesson you learned about:

The National Hydrography Dataset, Watershed Boundary Dataset and 3D Elevation program

NHDPlus

NHDPlus High Resolution

And how to get the data and additional information about the products.