# Porosity and Permeability. Which surface material will allow water to infiltrate in or run-off?

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Porosity and Permeability

Which surface material will allow water to infiltrate in or run-off?

What determines if precipitation will INFILTRATE the ground or RUN-OFF the surface?

Predict which will allow the water to infiltrate better soil sand gravel

Permeability Ability to transmit water through connected pore spaces http://www.classzone.com/books/earth_science/terc/content/investigation s/es1401/es1401page03.cfmhttp://www.classzone.com/books/earth_science/terc/content/investigation s/es1401/es1401page03.cfm Permeability of shale, sandstone and limestone

Amount of pore spaces, openings. Ground materials ability to store and HOLD water. The percent % of the total volume of material that consists of pore spaces

Porosity & Permeability Lab Predict which material will have the greatest permeability to water. Which material transmitted the most water through in the LEAST AMOUNT OF TIME? Which material transmitted the MOST water through it?

Results: Permeability Large grained, passes through easily. __________ Fine grained, passes through slowly. ___________ Very fine grained, cannot pass through at all. ____________ Highly porous but doesn’t pass through__________ material gravel, coarse sand Fine sand Clay, shale Pumice rock The pore spaces aren’t connected! (impermeable)

Amount of pore spaces, openings. Ground materials ability to store and HOLD water. The percent % of the total volume of material that consists of pore spaces

Porosity factors: 3-S’s Size of particles: (large, small, fine) Shape of particles (rounded or angular) Sorting of particles: - well-sorted: all the SAME size and shape - unsorted: mixed, DIFFERENT size and shape Compactness of particles Which is well-sorted? Compacted? Un-sorted?

sa Rank the following as #1 for the highest porosity and #5 as the lowest porosity. And describe factors Good porosity Due to: Round shape Same size well-sorted LOW porosity Due to: unsorted Small clay particles fill-in the pore spaces between the large particles. High porosity Due to: Same big size Same shape Well-sorted High porosity Due to: Big size But.. unsorted and angular Good porosity. Due to: Same size Well-sorted sand Clay soil

Post-lab graphs Unsorted well-sorted porosity 1. Sketch a graph that shows the relationship between porosity and particle size 2. Sketch a graph showing the relationship between porosity and sorted Particle size 3. Sketch a graph showing the relationship between porosity and shape. (round vs. angular)

Lag Time: the time between rainfall and when the water reaches the river as discharge Permeability vs Streamflow

Factors: Whether rain will infiltrate the ground or run-off is determined by POROSITY and PERMEABILITY of the ground material.

Permeability and Porosity Activity Use the Google Picture of the area. Decide if each square is Permeable or Impermeable and put that color tally mark on the square. Tally the total of each in the chart. Use the article to help you answer the questions.

Aquifer – water that infiltrates and is stored underground in the spaces between the rock particles. Groundwater

U. S. Aquifers

How much space is in sandstone for it to hold water?

Groundwater is the most abundant available source of fresh water Rivers, lakes, streams = 1.4% of fresh water

Zone of aeration Unsaturated zone Pore spaces are filled mainly with air Zone of saturation All pore spaces in the material are filled with water Water within the pores is groundwater Water table – the top of the zone of saturation

Groundwater Contamination Caused by: Sewage from septic tanks Highway salt Fertilizers, pesticides Industrial chemicals that leak from pipes and storage containers Landfill

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