Lecture 9

4 Pages
Unlock Document

Environmental Science
Tanzina Mohsin

Lecture 9: Guest Lecturer: Groundwater Lakes, rivers etc. Are surface water Groundwater is out of public sight and out of political mind o Probably worlds most important resource Since ancient time, ground water key to human survival hidden treasure Groundwater important for Aboriginals, marked springs on their maps Middle East, China, ground water taken from wells were important for birth of modern civilization Ancient examples of surface water management Roman dream back in days was moving water around They knew how much water they had available, knew when and how to move it Used aqueducts to manage water supplies Science of groundwater is young dates back to 1856 (150 years) on fountain in Dijon, France Henry Darcy Knowledge and understanding of how groundwater stored- in aquifers- dates back to Meizner Ground and surface water derive from same atmosphere source rain or snow- probably only similarities 4 major differences between ground and surface water systems o Water pathways and regional distributions of resource o Volumes in storage o Flow velocities including directions, how quickly water moves o Chemical and contaminant behaviour What is Groundwater? Part of the water cycle- hydrologic system Some water moves into aquifer, once it moves into aquifer, goes into groundwater system Key to sustainable resource management is understanding and quantifying all components of hydrologic cycle Infiltration storage discharge Aquifers All rocks capable of storing water, only most permeable rocks capable of supplying or transmit water to well, then we have an aquifer Rocks which can store water but are poorly permeable called aquitards Ability of rock to transmit water is called hydraulic conductivity- how easily water moves across rocks Percentage of pore space in rocks is porosity Porosity doesnt mean permeable Permeability: ability of rocks to transmit water Permeability Ease with which fluid can move through soil or rock Sand- high permeability, clays- low Porosity is % of pore space, contains water or air Some sediments e.g. clays have high porosity (~50%) but very low permeability Porosity and permeability can be primary or secondary Primary: pore space and permeability due to naturally occurring interstices within rock Secondary: pore space and permeability due to fracturing and chemical dissolution (fracturing, or chemically dissolved) Many rocks rely on secondary processes Aquifers come in 2 flavours Unconfined or water table aquifers www.notesolution.com
More Less

Related notes for EESA07H3

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.