GLY-1103 Lecture Notes - Lecture 12: Aggradation, Thalweg, Progradation
Document Summary
Drainage basin (watershed)- the source region from which a stream draws its water. Divide- ridge or crest that separates drainage basins from one another. Runoff- precipitation that moves across the ground to enter streams. Infiltration/percolation- absorption and movement of precipitation or surface water into ground water. Discharge- volume of water moving past a point in a stream in 1 second-- q=wdv. The fastest part of the stream is called the thalweg. There is more friction in wider, shallower streams. The gradient is typically the steepest near the headwaters and the shallowest towards base level. Affects sorting/ affects rate of downcutting or aggradation. Traction load (bed load)- heavy debris rolled, pushed, or dragged across the stream floor. Suspended load- material suspended by turbulence of the stream. Dissolved load- material completely dissolved into the water. Shape of stream is also related to the type of material being cut into.
