GEOG 120 Lecture Notes - Lecture 14: Landform, Lithosphere
Document Summary
Dynamic in that it varies spatially in different states. Today: infiltration and hydrology; runoff (overland flow), stream flow and floods; fluvial processes and landforms. Hydrosphere: one component of earth"s planetary system, essentially a closed system. Water covers 71% of global surface. Dynamic cycle of water movement through all spheres (atmosphere, lithosphere, biosphere) Major agent of landform change. Can be a major component of transporting energy throughout the earth system. Rain droplets initiate erosion. Overland flow removes soil layers. On steep slopes, may lead to rill and gully erosion. Rainwater seeps into ground. Gravity moves water downward through zone of aeration. Spring emerges where water table intersects the surface. Groundwater percolates along curved paths and emerges in nearest stream. Mechanics of channel flow see channeled flow diagram in text. Water tends to flow more quickly along the centre/midpoint of the channel (consider fluid mechanics friction factor) Velocity varies from surface to base and shore to shore.