Presentation on theme: "This volume of water has been recycled ever since."— Presentation transcript:
1This volume of water has been recycled ever since. The Water CycleWater vapor was “out gassed” during Earth’s cooling process some 4.5 billion years ago.This volume of water has been recycled ever since.
2Infiltration Runoff Water retention Evapotranspiration What happens to precipitation that reaches the Earth’s surface?Water retentionInfiltrationWater is trapped on the Earth’s surface as snow or ice.Water “seeps” or infiltrates into the soil.RunoffEvapotranspirationWater moves across the surface of the Earth to a large body of water.Water is evaporated and/or transpired back into the atmosphere
3What factors can affect the infiltration of water into the soil? Slope of the landThe steeper the slope, the less likely water will infiltrate into the ground.Slope of the LandRate of Infiltration
4What factors can affect infiltration? Vegetation and Land UseInfiltration tends to be higher in areas where vegetation covers the soil (ie: grasses, shrubs, trees).Infiltration tends to be poor in areas where the land has been used by people (ie: compacted soil of farms and/or city landscapes covered by asphalt).Amount of vegetationAmount of land used by peopleRate of InfiltrationRate of Infiltration
5Soil SaturationZone of aeration: Area of the soil in which space between soil particles is partially filled with air and partially filled with water.Water Table: The interface between the zones of aeration and saturation.Zone of saturation: Area of the soil in which all of space between soil particles is filled with water (GROUNDWATER).
6As the ground becomes saturated with water, the water table rises As the ground becomes saturated with water, the water table rises. As the water table rises, the chance of water infiltrating the soil will decrease.Soil SaturationSoil SaturationRate of Infiltration
7PorosityPorosity: The amount of “open space” (pore space) between soil particles compared to the total volume of soil.If the amount of “pore space” between soil particles is high, then water will infiltrate the soil more easily.pore spaceSome soil types have a high porosity due to the size and shape of the soil particles.PorosityRate of Infiltration
8Factors that affect Porosity ShapeRound soil fragments have a higher porosity than angular soil fragments.Round fragmentsHigh PorosityAngular fragmentsLow Porosity
9Factors that affect Porosity SortingSoil fragments that are roughly the same size and shape (sorted) will have a higher porosity than those that are not the same size and shape (unsorted).SortedHigh PorosityUnsortedLow Porosity
10Factors that affect Porosity PackingSoil fragments that are loosely packed will have a lot of pore space and will have a high porosity.Soil fragments that are compacted will have a small amount of pore space and will have a low porosity.Loose soilHigh PorosityPacked soilLowPorosity
11Which soil type do you think has the highest permeability? Permeability: The ability of a material to allow a fluid to pass through it.Different soils have different levels of permeability – or the rate at which water can move through the soil.Which soil type do you think has the highest permeability?Sandy soil has the highest permeability.
12Which soil sample below has the smallest particle size? CapillarityCapillarity: The upward migration of water in soil against the force of gravity.Capillarity is commonly found in soils with loosely packed, small particle size.The larger the particle size of the soil; the lower the rate of capillarity.Which soil sample below has the smallest particle size?The clay soil sample has the smallest particle size. The clay shows the best evidence of capillarity as seen by the highest upward rise of water in the sample.CapillarityParticle Size
13What factors can affect the runoff of water on Earth’s surface? Rate of PrecipitationSoil SaturationIf the rate of precipitation is higher than the rate of infiltration, runoff will occur.If the soil is saturated with water, runoff will occur.Slope of the landRate of EvapotranspirationIf the slope of the land is steep, runoff will occur.If the rate of evapotranspiration is low, runoff will occur.