1. Big Cypress/Caddo Watershed Geomorphic Classification
Ryan Smith
The Nature Conservancy of Texas

2. Utility of River Classification
Understand watershed context of the river
Understand normal channel, habitat, and biological characteristics
Understand impacts on natural characteristics
Selection of reaches for studies of habitat, water quality, riparian, etc

3. River Styles Brierly and Fryirs 2000 Developed in Australia
Selected by TCEQ, TPWD, and TWDB for Texas Instream Flows Program
Meets recommendations of NAS review
Physical basis
Channel morphology
Hierarchical structure
Physiographic/hydrologic setting
Floodplain and riparian zone

4. Stages of a River Styles Procedure
Stage 1 Data Compilation (description and mapping)
• Derive watershed boundary conditions
• Determine landscape units
• Assess river character
Stage 2 Data Analysis
• Define and interpret River Styles
• Explain contemporary character/behavior • Assess river history
Stage 3 Predict future river structure
Stage 4 Prioritize watershed management issues
Stage 5 Identify target conditions for river

5. River Styles Hierarchy
Watershed
Watershed area determined by drainage divide. Determines the boundary conditions within which rivers operate.
Landscape Unit
Topographic unit determined on the basis of local relief, valley slope and morphology. Defines the valley-setting.
River Style
Length of channel with a characteristic assemblage of geomorphic units.
Geomorphic Unit
Instream and floodplain landforms (pools, bars, levees, backwaters, etc.) that reflect distinct form-process associations.
Hydraulic Unit
Uniform patches of flow and substrate material within a geomorphic unit.
Microhabitat
Individual elements (e.g., logs, rocks, gravel patches) within a stream.

6. GIS Data Atlas TNC NFWF grant
GIS data atlas for the Caddo Lake watershed
West Gulf Coastal Plain aquatic conservation priorities
Considering development of data for River Styles Stage 1 analysis of Big Cypress Bayou watershed
TNC aquatic ecosystems classification
Many river characteristics calculated in a GIS
Consider data’s usefulness for River Styles
Consider developing additional data in the data atlas work

7. TNC Aquatic Ecosystems Classification
Mapped in 1:100K National Hydrography Dataset
Variables:
Watershed area
Gradient
Contributing area geology
Longitudinal connectivity

8. River Styles for Big Cypress Watershed?
Undertake a River Styles analysis for Big Cypress Bayou watershed?
Value added?
Relationship to other studies (e.g., channel cross-sections)?
Relationship to characterization, classification of hydrologic regime
What are the most important aspects of river characteristics in the area that would need to be included in the development of River Styles here?
Watershed characteristics?
Landscape, geomorphic unit characteristics?
What data are needed?
Is TNC’s data useful? What else needed?
Limitation of geomorphology expertise

9. River Styles: Australian Example
Watershed
Namoi River Basin, New South Wales
Macdonald/Manilla
Sub-basin
Lower Namoi Sub-basin
Peel Sub-basin
Middle Namoi Sub-basin 25 50 75
100
Kilometers
Mooki Sub-basin

10. River Styles: Australian Example
Watershed
Namoi River Basin, New South Wales
Landscape
Unit 25 50
100
Kilometers
Legend – Landscape Units
Liverpool plains
Pillaga outwash
Lowland plains
Rugged metasediments
Mid to lower Peel
Rugged volcanics
Pillaga
Uplands

11. Vertically Accreated Floodplain River Style Floodplain Accumulation
Landscape
Unit
Uplands Escarpment Base of the Escarpment Rounded Foothills Lowland Plain
Channel
Slope
Channel and
Valley Width
Planform
Valley Cross Section
Head-water
Cut & Fill (Incised)
Vertically Accreated Floodplain
River Style
Floodplain Accumulation
Fan
Cut & Fill (Intact)
Floodout
Gorge
Throughput
Transfer

12. River Styles: Australian Example
Watershed
Middle Namoi
Sub-basin
Landscape
Unit
River Style 25 50
Kilometers

13. Geomorphic Unit Hydraulic Unit Microhabitat
Trailing Vegetation
Backwater
Rippled flow on cobbles
Submerged Macrophyte
Riffle
Barely perceptible flow on sand
Cobbles
Smooth surface flow on cobbles/sand
Floodplain
Large Woody Debris
Pool
Smooth surface flow on cobbles
Run
Bar
Secondary Channel
Boulders
Sand
Pool
Barely perceptible flow on sand/boulders
Leaf Pack