1. STREAM NETWORK DELINEATION USING ARC HYDRO AND TauDEM: A comparison of approaches using The Upper Sevier and the Little Bear River Basins
Alphonce C. Guzha

2. OBJECTIVES (a) To evaluate river network delineation using:
Arc Hydro tools
Terrain analysis using Digital Elevation Models (TauDEM)
The National Hydrography dataset
(b) Compare drainage densities obtained from each of these methods

3. Upper Sevier
The Upper Sevier River Watershed covers the headwaters of the Sevier River, Garfield, Iron, Kane, Wayne and Piute Counties in south-central Utah.

4. Little Bear

5. Data Sources Data for this project was obtained from :
NED
NHD

6. Arc Hydro The following procedures were performed:
Terrain Preprocessing
DEM reconditioning
Filling sinks
Flow direction and accumulation
Stream definition and segmentation
Catchment grid delineation and polygon processing
Drainage line processing and adjoint catchment processing

7. TauDEM
Seven different procedures for stream network delineation available:
Use of existing streams
DEM curvature based approach
Contributing area threshold
Grid order threshold
Area and slope threshold
Area and length threshold

8. For this project I selected only three methods:
Existing streams-Stream network raster defined from D8 flow directions function
DEM curvature based-Method flags entire grid and examines each quadrant of 4 grid cells and unflags the highest. Remaining flagged cells are deemed "upwards curved" and these define the channel network.
Contributing area threshold-  A threshold on the contributing area is computed by the D8 method and this is used to delineate streams.

9. DEMs
UPPER SEVIER
LITTLE BEAR

10. Results Upper Sevier
ArchHydro
NHD Flowlines

11. ArcHydro
NHD
Length of drainage (km)
1840.5
2488.4
Drainage area
(km2)
3115.2
3222
Density (km-1)
0.59
0.77

12. Little Bear
NHD flowlines
ArcHydro

13. NHD
ArcHydro
Length of drainage (km)
559.36
462.2
Drainage area
(km2)
743
717
Density (km-1)
0.75
0.64

14. Upper Sevier
TauDEM
DEM curvature based

15. Little Bear
TauDEM
DEM curvature based

16. Upper Sevier Parameter DEM curvature Existing streams
Contributing area Threshold
Drainage Density
(km-1)
0.63
0.69
0.72
Drainage Length
(km)
2039
1998
2178
Drainage area
(km2)
3236.5
2897.0
3025.1

17. Little Bear Parameter DEM curvature Existing streams
Contributing area Threshold
Drainage Density
(km-1)
0.66
0.61
0.70
Drainage Length
(km)
471.9
420.3
506.5
Drainage area
(km2)
715
689
723.5

18. Threshold Levels Upper Sevier ArcHydro- 6 Existing streams –8
DEM curvature – 8
Contributing area- 15 (automatically selected)
Little Bear

19. General conclusion Generally the different methods used give values of drainage density that close match. The various TauDEM tools give results that are close to each other and closely match the NHD networks The value of the stream threshold used is very critical in the delineated networks

20. ?????