# Presentation: 699252

## Spatial Data Activities Related to Surface WaterWATERS ForumWashington, DCDecember 4, 2003

## ACWI/FGDC  Subcommittee for 

**Surface water **
**geospatial **
**framework**

**ACWI/FGDC  Subcommittee for **
**Spatial Water Data**

**Notes:**
Focus of the Subcommittee is getting these datasets developed and available.  Important that these data sets work together.

## Vision:

- Follow a drop of water from where it falls on the land, to the stream, and all the way to the ocean.

## Watershed Boundary Dataset (WBD)

**2-digit (1st level) 22 regions**
**      ****ave.-177,560 sq. miles**
**4-digit (2nd level) 222 subregions**
**      ****ave.-16,800 sq. miles**
**6-digit (3rd level) 379 basins**
**      ****ave.-10,596 sq. miles**
**8-digit (4th level) 2,267 subbasins**
**      ****ave.-703 sq. miles**
**10-digit (5th level)**
**      ****40,000 – 250,000 acres**
**         ****est.-22,000 watersheds**
**12-digit (6th level)**
**      ****10,000 – 40,000 acres**
**         ****est.-160,000 subwatersheds**** **

**4th Level**

**5th Level**

**6th Level**

**Watershed Boundary Dataset (WBD)**

**Notes:**
Visual comparison between existing HU’s versus the two new 5th and 6th levels.  As you can see the 5th (left side)  and 6th levels (right side) covers a much smaller geographic area then the existing 4th level (top).  

The 5th and 6th level is much more dense over an area the size of a state then the original HUCs.  

The estimated number of watersheds is 22,000 while the estimated number of subwatersheds is 160,000.  This is a big increase from the 2,267 subbasins that currently exist.

## Slide 5

## 
EGOV Initiative - Geospatial One-Stop
Establish Framework Data content standards 
Elevation
Orthoimagery
Hydrography
Administrative Boundaries
Transportation Networks
Cadastral
Geodetic Control
Establish Federal Portal

**EGOV Initiative - Geospatial One-Stop**
**Establish Framework Data content standards**
- Elevation
- Orthoimagery
**Hydrography**
- Administrative Boundaries
- Transportation Networks
- Cadastral
- Geodetic Control
**Establish Federal Portal**

**National Hydrography Framework Standard**** **

## Not just “integrated” 

**but “*****interoperable*****”**

## NHD-NED Synchronization

**The Goals:**
**Catchments for every NHD Reach**
**Enhance NHD with elevation-derived attributes**
**Tie over-land flow to NHD network**
**Enable NHD-based SPARROW, Time-of-Travel models**
**The Team:**
**USGS Mapping: Sue Greenlee, Kris Verdin, Bruce Worstell**
**USGS Water: Greg Schwarz, Craig Johnston, Rich Moore, Pete Steeves, Al Rea**
**EPA and Contractors: Tommy Dewald (OW), Cindy McKay, Tim Bondelid, ****Michelle Thawley (OPP)**
**U of Texas: Dr. David Maidment, John Goodall**

## Slide 9

## Indexing USGSNational Water Information System Gaging Stations to the NHD

**Goals:**
**QA locations of gages in NWIS **
**Proper placement of gages on NHD**
**How will we do this?**
**EPA team “snapped” to nearest NHD reach in an automated process**
**Each District to review the results**

## Correct location

**Correct location**

**NWIS Location**

**Snapped here**

**Notes:**
Districts can view the data with their own base maps, or bring in imagery from Terraserver. If they find an error, they will correct it by entering the correct location in WebRIT.

## Testing Results

**Tom Brennan, Idaho District**
**Reviewed ~200 active gages**
**Time required: < 8 hrs (~ 2 min/gage)**
**Moved 21 sites and/or NHD locations**
**Inactive gages may take slightly longer to research**
**“****Like a video game”**

## MAPPING PERENNIAL ANDINTERMITTENT STREAMS

**Developed a logistic regression equation to estimate the probability of a stream flowing perennial **
**    ****(Massachusetts District)**
**Developed a logistic regression equation to determine nominal stream density range **
**    ****(Georgia District)**

**Notes:**
The Commonwealth of Massachusetts Rivers Protection Act of 1996 established a 200-foot-wide protected riverfront area on each side of a perennial stream and no protected riverfront area along an intermittent stream. These Regulations specified that USGS topographic maps be used in the initial review of the perennial or intermittent status of a stream. 

The Massachusetts Department of Environmental Protection (MADEP) and City and town conservation commissions are charged with administering the Regulations by determining the perennial or intermittent status of a stream site and by regulating work in the riverfront areas. 

A problem, however, is that USGS topographic maps generally do not show the level of detail presumed by the Regulations; therefore, they may not accurately represent whether a stream site is perennial or intermittent. 

The USGS, therefore, in cooperation with the MADEP, began a study in 2001 to develop a method for mapping the intermittent and perennial status of streams in Massachusetts. 

The mapping procedure involves using a logistic regression equation, developed to estimate the probability of a stream flowing perennially at a specific site, and an automated GIS procedure to map the intermittent and perennial status of stream reaches in Massachusetts. 

## AUTOMATED GIS PROCEDURE MOVING UP AND DOWN TRIBUTARY SOLVING EQUATION TO MATCH DESIRED CUTPIONT PROBABILITY

**AUTOMATED GIS PROCEDURE MOVING UP AND DOWN TRIBUTARY SOLVING EQUATION TO MATCH DESIRED CUTPIONT PROBABILITY**

**Pete Steeves, MA**

**Notes:**
An automated geographic information system (GIS) procedure was developed in ArcView 3X which uses the National Hydrography Dataset (NHD) and the NHD ArcView Toolkit, including the NHD Watershed Tool and Characteristics, to run a batch process to determine the perennial or intermittent status of stream sites along a given reach throughout a watershed. 

The automated procedure starts on first order streams 10 m up from the confluence by determining the explanatory variables (drainage area, percent area of sand and gravel deposits, mean basin elevation, and percent area of forest land) and solving the logistic regression equation. Then the procedure moves to 10 m downstream of the first order streams headwaters and solves the equation. 

If both the confluence and headwater probabilities are less than the set cutpoint probability (for example, a probability of 0.50) the stream reach is classified intermittent

If both the confluence and headwater probabilities are greater than the set cutpoint the stream reach is classified perennial

If the confluence probability is greater than the set cutpoint and the headwater probability is less than the set cutpoint. The procedure continues to loop up and down the stream reach, half the stream length, between probabilities less than and greater than the cutpoint, as needed, until it finds the breakpoint location between probabilities above and below the set cutpoint (conceptually, the transition point from an intermittent to a perennial stream reach during low-flow periods of the summer). 

##  NHD Drainage Density Artifacts

**What should the stream density be?**

**Keith McFadden, GA**