Elevation and depth are measures of the height of a point on the surface of the sediment or soil of a location, expressed relative to a datum point (e.g., NGVD29, MLLW).
Bathymetry is a collection of depth points that represent the gradients of elevation and depth change along a surface. Changes to elevation/depth often alters the dessication stress and amount of light reaching the bottom for aquatic organisms.
The figure at bottom left shows a cross-sectional diagram of habitat types at various elevations in an estuary (based on Procter et al. 1980a). The figure at bottom right shows bank-to-bank bathymetry from the U.S. Army Corps of Engineers (2003-2004).
Stressors that affect elevation/depth/bathymetry:
- Extreme climatic events
- Marinas and overwater structures
- Seismic activity
- Shoreline armoring
- Volcanic activity
Ecosystem structures that are affected by elevation/depth/bathymetry:
- Scrub-shrub forest
- Emergent marsh
- Mud / sand flats
- Submerged aquatic vegetation
- Shallow slope
- Deep channel
Interactions and equations: