GEOG 141 Lecture 16: Geog 141 Lecture march 7
12 Mar 2018
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Document Summary
Baseflow: the minimum amount of water in a river at a given time of year. So(cid:373)e portio(cid:374) of (cid:449)ater is i(cid:374)filtrated i(cid:374) soil. Whe(cid:374) its pa(cid:448)ed, it (cid:272)a(cid:374)"t go i(cid:374)to soil a(cid:374)d ru(cid:374)s off i(cid:374)to water very quickly. If velocity increases, then area must decrease (shallow rapid) Speed up water to make it the same amount. We can look at graphs of annual peak flow. Each dot is the single highest discharge in a year; single flood event. Evaluate statistics of recurrence: not a prediction per say. High occurrence interval: 1 to 2 years. Amount of water, such that the channel is full. Average flows too small to move anything. Shape of channel is in equilibrium with water it holds. The two-year flood event is what the channel is in equilibrium with: bank full flow and powerful enough and frequent enough, base flow is energy but not enough to erode material.
