learning targets i can explain the connection between surface water and groundwater. i can relate...
TRANSCRIPT
Learning Targets• I can explain the connection between
surface water and groundwater.
• I can relate the processes of infiltration and evaporation to groundwater & surface water.
• I can describe how water moves through the lithosphere.
The Water Cycle
2.3.2
Infiltration
Infiltration - process by which precipitation enters the ground and becomes groundwater.
Well sorted sedimentsHigh porosity
Poorly sorted sedimentsLow porosity
Factors affecting Infiltration
• Vegetation
• Rate of Precipitation
• Soil Compaction
• Surface Slope
Vegetation
• Soils that contain grasses or other vegetation allow more water to enter the ground than do soils with no vegetation.
• In areas with little vegetation, soil particles clump together and form dense aggregates with few pores or spaces between them.
Rate of Precipitation• Light, gentle precipitation infiltrates the dry
ground.
• During heavy precipitation, water falls too quickly to soak into the ground and becomes runoff.
• Thus, a gentle, long-lasting rainfall is more beneficial to plants and causes less erosion by runoff than a torrential downpour.
Soil Compaction• Soil with large particles has large pores and
allows water to enter and pass through the soil quickly.
• Humus creates pores in the soil, thereby increasing a soil’s ability to retain water.
• Soil with fine particles clumps together and has few or no spaces between the particles.
• Small pores restrict both the amount of water that can enter the ground and the ease of movement of water through the soil.
Surface slope
In areas with steep slopes, little water infiltrates into the ground before it runs off.
Lab
•Porosity is the percentage of pore space in a material.
•Permeability is the ability of a material to let water pass through it.
Groundwater• The zone of saturation is the depth below
Earth’s surface at which groundwater completely fills all the pores of a material.
• The water table is the upper boundary of the zone of saturation.
• The depth of the water table varies depending on local conditions.
• The topography of the water table follows the topography of the land above it.
Fractured Rock Aquifers• In metamorphic and/or igneous rocks, there are
rarely confined aquifers.
• Instead, water is contained within the rock itself in fractures and pore spaces.
• Generally, the fractures decrease as depth increases, due to pressure.
• In WNC, more than 50% of the population receives their water from wells drilled into fractured rock aquifers.
Evaporation within the Water Cycle
• Evaporation is what drives the surface-to-atmosphere connection of the water cycle
Evaporation
•Water vapor in the atmosphere
– 90% comes from surface waters – 10% from transpiration from plants.
•Heat energy is required to change water in its liquid form to its gaseous form.
•If you add heat to a material, does its temperature always rise?
Evaporation
• Water in its gaseous form is a heat “carrier.”
• Once condensation occurs, the heat energy is released back into the atmosphere.
• This is called latent heat, and serves to warm the atmosphere.
