Notes on river profiles

You will want to review parts of the powerpoint to make sure all is clear on how we measure concavity and ksn, what the reference concavity (typically set to 0.45) is and why we use it, and how tectonics is expressed in landscapes by channel steepness (ksn – remember all else equal high ksn = high erosion rate implies high rock uplift rate). For this walk through slides 31-40 (including any animations) to make sure it all makes sense, and ask any questions inspired by that review.

Slides 41-59 and show a few examples that I think will be self-explanatory (the first example from the Waipaoa in New Zealand is an example NOT well explained by the stream power model because of all the waterfalls), so consider slides 31-59 your reading assignment.

Slides 61-73 (Part V) are to guide a discussion of the complications caused by the fact that rivers are often at least partly alluviated and erosion can be limited by the river’s capacity to transport sediment, not just its capacity to erode rock, which is what the stream power model is intended to describe.

Slides 74-85 (Part VI) are another example – from the Siwalik Hills in Nepal (the small hills on the Main Frontal Thrust where India underthrusts Asia).