GEOL 213 Lecture Notes - Lecture 17: Subduction, Strahler Number, Point Bar

• School: College of Charleston
• Department: Geology and Environmental Geosciences
• Course: GEOL 213
• Professor: Jaume'

Document Summary

Flood hazards are largely controlled by the topography of the landscape. Floods can occur at almost any elevation; the slope of the landscape, style of precipitation and surface geology largely control the type of river & therefore type of flooding. Land area from which river gets all its water. Maximum possible water in river is controlled by size of drainage basin. It takes more rainfall to create flood on river with larger drainage basin. small drainage basin. All runoff/snowmelt goes into stream exiting basin at bottom of v . Edges of drainage basin are called drainage divides. 2nd order are when 1st order streams come together. Drainage basin size increases as stream order increases. Usually steep gradient -near but not in mountains/glaciers. More sediment than water can move during dry part of year. Gravel only moved during spring floods river must go around sediment remainder of year. Shallow gradient -in flat and often low lying regions.