ENV334H1 Lecture 8: L8-Watersheds
Document Summary
Lecture 8: land use affects hydrological processes & water quality in rivers. Early manipulation of water: mesopotamia, one of regions where agriculture developed, between 2 rivers, people built intricate canal systems, egypt. Cities were built close to water: most large cities built near water. How the water gets to a stream is important: water budget: Evapotranspiration: but a lot captured by trees and returned to atmosphere. Inputs: precipitation (rainfall, stem flow, rainfall flows along branches and flows along trunk, goes straight to roots, throughfall, leaves drip water to ground. Outputs: canopy interception (rainfall, some just stays on leaf and gets evaporated, transpiration, plants lose water physiologically, litter evaporation. If rainfall makes it down to litter: evaporation from litter itself (any evaporation sends part of water back to atmosphere, how much that is depends on surface area, = part of rainfall not available to system.
