This document discusses a study that uses 2D hydrodynamic modeling and topographic data to delineate morphological units (MUs) within river corridors. MUs are distinct landforms controlled by ecohydraulic variables that can be identified at lengths around 1-10 times the river width. The study presents a method to delineate MUs by combining hydraulic modeling data with digital elevation models and LiDAR data. Delineating MUs in this way allows researchers to better describe the underlying landforms and habitats within a river system. The document provides examples of applying this MU delineation procedure to different river types and concludes by discussing potential correlations between MUs, river discharge, and spatial variability.

1. Revealing the natural complexity of fluvial
morphology through 2D hydrodynamic
delineation of river landforms
Wyrick J.R., Senter A.E., Pasternick G.B., (2013)
Evan Norman - Geographic Information Analysis - 2.27.2015
Shaded relief map of a streambed

2. What is a morphological unit (MU)?
“Topographic forms within the river corridor
that represent distinct form-process
applications.”
-Controlled by ecohydraulic variables
-Near-census
-In this study, applicable at lengths ~1-10 times W

3. How are MUs delineated?
Hydraulics (water flow)
+
DEM and LiDAR data
(Landforms)
=
MU

4. Why are MUs calculated?
-Describes underlying landforms in a river
with 2D modeling
-Habitat assessments

5. -Subjectivity
-Changing flow conditions
-“Ideal” conditions
-Increasing MU types
-Overlap of zones
-Flow direction
Drawbacks

6. Example MU delineation procedure for a lowland gravel-cobble river
-Spatial Analyst- Raster calculator
-Irregular shapes
-Precise
-Thresholds are adjusted by
discharge in model
More about MU mapping..

7. Example MU delineation procedure for an upland cobble-boulder river

8. Conclusions:
How do riffle-pool sequences correlate with discharge?
How are MUs distributed?
Lateral or longitudinal variability?
Spatial scales.
Riparian species.