EES 1030 1st Edition Lecture 16 Intro to Earth ScienceRunning Water:Hydrological cycle: continuous circulation of earth’s water among oceans, atmosphere and continents.The global water supply is circulated by a series of a key processes. - Evaporation- Transpiration- Precipitation- Infiltration- RunofEvaporation: the process of water turning from liquid to vapor, moving from the hydrosphere to the atmosphere.Transpiration: release of water vapor into the atmosphere by plants through pores in leaves; plants absorb water from the ground through their rootsPrecipitation: water (rain, snow, sleet, hail) that falls to the ground from atmosphere to the hydrosphere Infiltration: the process of water draining into the ground through cracks and pore spaces in regolith Surface runof:water flowing over the land rather than infiltrating the ground (streams, rivers)Running water:Running water: most important erosional agents afecting earths land surface Infiltration vs RunofThe maximum amount of water that can be absorbed is the infiltration capacity. Infiltration capacity is controlled by:- Intensity and duration of precipitation- Soil saturation level prior to precipitation- Soil texture- Slope of the land - Vegetation time and extentSheet flow: water draining that is not in a specific confined channelErosion by runoff: Sheet flow can erode soil and the land into rills. Continuous runof can widen and deepen the rills making them gullies, ravines, canyons.Rivers and Streams:Runof is called by many names: rivers, streams, creeks, tributaries, etc.Efects: Size of channels, amount of sediments provided by weathering and mass wastingStraight channel: stream where water molecules flow in a straight path. Meandering: erratic flowing streams and rivers, can be curvy. What efects velocity:- Gradient: Slope of channel- Discharge: Shape, size, and roughness- Volume of water Streamflow discharge:Discharge: volume of water flowing past a certain point in a given unit of timeUsually measured in cubic meters per secondCalculated by multiplying a streams cross sectional area by it’s velocityDrainage: land areas where runof drains downhill into a waterway or body of water. Drainage basin can also be called a watershed or catchment areaDrainage network: interconnected system of tributaries, creeks, streams, rivers in a drainage basin that feed into a main waterwayDivides: each drainage basin is separated topographically from adjacent basins by a ridgehill or other topographic high lineThe great divide: mountainous line that forms between major watersheds in North America Capacity: maximum load a stream can transportCompetence: the largest sediment that can be transported by the streamDisolved load: transporting sediment in solutionSuspended load: transporting sediment in suspensionBed load: transporting sediment along the bedSorting: like sized particles are deposited togetherAlluvium: type of stream deposit that can occur as channel deposits called barsNatural levee: elongated naturally occurring ridge or artificially constructed fill or wall that regulated later levels Delta: landform that forms at the mouth of a river where the river flows into an oceans, sea, or estuaryAlluvial fans:a fan shaped mass of alluvium deposited as the flow of a river decreases in velocityStream valleys: the most common landforms on a continental
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