GLY-1104 Lecture Notes - Lecture 4: Cut Bank, Oxbow Lake, Alluvial Fan
Document Summary
Profile ideally steeper at headwaters and flatter near mouth concave-up profile. Base level- lowest level to which a stream can erode. Streams cannot erode below sea level in general, base level is ocean, lake, or basin into which it drains. For most systems, ultimate base level is sea level/ ocean. Rock type-waterfalls and nick-points: easily eroded = smooth, equilibrium-like profile concave-up shape, more erosion-resistant = steeper slope, cliffs, waterfalls, steep rapids, narrow canyons, alternating- stair step topography. Tectonics: can cause uplift/ subsidence of whole region affects gradient: subsidence- flatten/steepen gradients, uplift: generally causes erosion down into landscape canyons steepening topography. Climate: increases/decreases in rainfall affects amount of water: wetter more vegetation holding soil higher discharge allows more sediment being carried hills decline. Stability of conditions graded stream: stable = stream approaches equilibrium profile balance between sediment and carrying capacity, dynamic equilibrium neither eroding nor depositing material graded stream. Sinuosity: amount a channel curves for a given length.
