NHD Stream Order Possibilities
Timothy R. Bondelid
Research Triangle Institute
Research Triangle Park, North Carolina 27709
(919)485-7797; fax (919)485-7777
e-mail: [email protected]
Topics
• The Three Main Characteristics of NHD (and all Reach Files)
• Hydrologic Sequencing and Routing
• Example of NHD Routing, Stream Orders, and Changing Network Density
• “Hydrologic Equity” Example
The Three Main Characteristics
• A Common Numbering Scheme for All Surface Waters in the System– The Reach Number
• A Map Representation of the Surface Water Features
• A Tabular/Database Routing Network
“Hydrologic Equity”
• Define the Network in Terms of Hydrologic Characteristics
• Example in ArcView (RF3) Using Mean Annual Flow Estimates
Summary
• Stream Orders Can be Made With NHD
• Stream Orders are “Sensitive” to the Density Issue
• The NHD is a Very Flexible Network– The Full Richness of the Network Can Be Used
for Varying Levels of Analysis, Display, and Modeling
Water Quality Management and Policy Modeling Tools using the
National-Scale Reach File 3 (RF3) Hydrography Network
Timothy R. Bondelid, Suzanne J. Unger, Randall C. Dodd, and Dario J. Dal Santo,
Research Triangle Institute
Research Triangle Park, North Carolina 27709
(919)485-7797; fax (919)485-7777
e-mail: [email protected]; [email protected]; [email protected]; [email protected]
The National Water Pollution Control Assessment Model (NWPCAM)
• This Work Has Been Funded by The U.S. Environmental Protection Agency
• Acknowledgements:– Dr. Mahesh Podar, Dr. John Powers, and Ms.
Virginia Kibler in the U.S. EPA Office of Water– Dr. Charles Griffiths in the U.S. EPA National
Center for Environmental Economics
• Significant Others:– C. Robert Horn, Mary Jo Kealy, George Van
Houtven, and Tayler Bingham
Agenda
• Overview of Approach
• Major Challenges
• Assessment Framework
• Hydrologic Components
• Example of Results
• Conclusions
Overview of Approach
Actual LoadingsPolicy Scenario
Loadings
W ater Quality M odel
Policy-Induced W aterQ uality C hanges
Benefits Assessment M odel
Policy Benefits
Major Challenges
• Need to be Able to Evaluate Large-Scale Changes Due to Pollution Control Policies
But: Water Quality is Generally a “Local” Issue
• Need to Link to Economic Benefits
• Addressing These Two Challenges Makes the System Unique
Assessment Framework
H ow m uch water?
H ow deep, w ide fast, e tc .?
Poin t sources (PS)N onpoin t sources (N PS)
M oving from reach to reach
W hat happens to the constituentsin the water?
W ater qua lity (W Q )
Hydrology
Transport
Kinetics
Effects
Loadings
Hydrodynamics
Reach Files and Modeling
• Any Reach File Contains Three Elements:– A Standard, Unique Identifier for Each Surface
Water Feature in the System– A Digital Map Representation of the Features– A Tabular Routing/Navigation “Engine” that is
Powerful and Fast
The Reach Files Have Been Used for Modeling Since 1982
RF3Lite in Upper Potomac
Reach File 3 Lite(RF3 Lite)
S
N
EW
HUC 02070003HUC 02070004HUC 02070008
Reach File 3(RF3)
Hydrology: How Much Water?
• Estimate Average Unit Runoff by HUC
• Estimate Drainage Area for Each RF3 Reach
• Route and Accumulate Drainage Areas and Flows Down RF3
Average Annual Runoff
• Use “Hydrologic Centroids” of HUC’s
• Apply Distance-weighted Average of Annual Unit Runoff for USGS NCD Gages
• Testing:– HUC-level Unit Runoff– Drainage Areas– Flows
USGS Flows Vs. RF3 Flows
USGS Flow vs RF3 Flow
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0 200 400 600 800 1000 1200 1400 1600 1800
USGS Flow
RF
3 F
low
How Deep, Wide, Fast?
H ow m uch water?
H ow deep, w ide fast, e tc .?
Point sources (PS)N onpoint sources (N PS)
M oving from reach to reach
W hat happens to the constituentsin the water?
W ater quality (W Q )
Hydrology
Transport
Kinetics
Effects
Loadings
Hydrodynamics
Basic Hydraulics
• Assume Rectangular Channel• Manning’s “n” is a Function of “Sinuosity” of
the Reach:– Sinuosity is the Reach Length/CFD
– CFD = “Crow Fly Distance”
– Reach “n” Increases as Sinousity Increases
• Slopes Derived From RF1/DEM-based Data• Channel Widths From RF3 Geometry or
Keup-derived Function for single-line streams
RF3Lite: Open Water Widths and Sinuosities
Reach File 3 Lite(RF3 Lite)
Open Water
HUC 02070003HUC 02070004HUC 02070008
S
N
EW
Channel Widths and Depths
• Single-Line Stream Widths (Keup):– W = 5.27 * Q 0.459
• Double-Wide Channel Widths from RF3 Geometry
• Depth: Manning’s Formula Assuming a Rectangular Channel– Y0 = 0.79 * (Q * n /(W * (S0)0.5)0.6
The Whole Process
H ow m uch water?
H ow deep, w ide fast, e tc .?
Point sources (PS)N onpoint sources (N PS)
M oving from reach to reach
W hat happens to the constituentsin the water?
W ater quality (W Q )
Hydrology
Transport
Kinetics
Effects
Loadings
Hydrodynamics
Example: Two Scenarios on a Stretch of River
Dissolved Oxygen Concentration
0
1
2
3
4
5
6
7
8
9
184018601880190019201940196019802000
P Mile
Co
nce
ntr
ati
on
(m
g/L
)
Baseline
Scenario
Conclusion: NWPCAM is an Evolving System with Every Component
Undergoing Enhancements
Actual LoadingsPolicy Scenario
Loadings
W ater Quality M odel
Policy-Induced W aterQ uality C hanges
Benefits Assessment M odel
Policy Benefits
Top Related