Laramie River field trip

Meet at Optimist Park, on south side of road, in the parking lot near the river bridge.

Objectives

The main purpose of the trip is to start looking at geomorphic landforms from a quantitative and process point of view. In particular we are going to look at a river in low flow conditions.

Measure the water discharge: we will use several techniques to measure water discharge. The simplest will be to measure the approximate width and depth of a river cross-section. We will then estimate the surface water flow velocity. The product of the width, depth and velocity should give an approximate discharge. Note it will tend to be too high since the actual cross-section will be less than the width x depth, while the surface water velocity tends to be higher than the depth averaged velocity. A correction factor of 0.6 or 0.7 is often applied to this crude discharge estimate.

We will divide into 3 or so teams to do this measure, and compare results.

I will demonstrate a flow meter to illustrate a more accurate means of river “gauging”.

A second objective will be to show the complexity of the flow, both the turbulence and the secondary current structure, even in a very low flow river.

Our final objective will be to observe and recognize typical river features such as bars, dunes, ripples, sinuosity, point bars, sediment sorting, and pool and riffle sequences. We will attempt to identify high flow features such as bankfull, levees, and floodplain regions.