lecture 17 groundwater - Results for Midterm#2 Overall...

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Results for Midterm #2 Overall Average* 60% Multiple Choice 71% Short Answers * 51% *includes many ‘zero’s who did not write or did not do the short answers
Questions from Last Lecture Are geologists licensed like doctors?
Explain the Unit Runoff concept? What types of flood control techniques can be used? Where and when? 2
Unit Runoff / Discharge What is the average discharge of the Ottawa River at the Carillon Dam (~Montreal)?
2 What is the annual average UNIT discharge of the Ottawa River?
3
Flood Control Techniques Controls ice jam removal- Winnipeg, Manitoba floodplain of Red River artificial levees dams channelization Natural Storage Areas Live elsewhere 4
GROUNDWATER
3. Dacy’s Law & Groundwater movement & ‘flow’1. GROUNDWATER: definition, importance and distribution Learning Objectives: 2. Groundwater reservoirs 5. Geologic features associated with groundwater 4. Problems with using groundwater resources
Hydrologic cycle (reminder) Distribution of Earth’s water1. Oceans: 2. Freshwater: 2a. 2b. 2c. 97.2% 2.8% glaciers: groundwater: Other: 0.03% lakes: streams: atmosphere: soil moisture: 2.15% 0.62% 0.009% 0.005% 0.0001% 0.001% Today’s lecture
Definition, importance and distribution Percentage of population reliant on groundwater for domestic use ~ 25-40% in Canada (~9-14 million people) ~70% in Maritimes Groundwater is a major economic resource …
GEO 1111 Introduction to Earth Systems Lecture 14 Definition, importance and distribution Groundwater: the water that lies beneath the ground surface. Hydrosphere's fresh water: 1. Glaciers (~77%) 2. Groundwater (~22%) In general, ~ 15% of total precipitation infiltrates ground and ends up as groundwaterGroundwater is slow moving, but not static: recharges (rain) discharges (feeds rivers)
drysoil saturatedsoil Solid Water Air Groundwater reservoirs Groundwater → found in poresof soil and sediment + fracturesof bedrock pores fractures
Groundwater reservoirs Controls on availability of groundwater Porosity (Φ): percentage of voids or pore space (vs. total volume). Determines how much groundwater can be stored. Φ = f(grain roundness, sorting, and cementation) → texture(… rounded, … sorted = high porosity)
Measurement of Porosity Volume of sand column = 1000mL Column contains sand plus porosity In dry sand the porosity is filled with air Replace all the air with water Porosity = volume water / total volume
Groundwater reservoirs Controls on availability of groundwater Permeability or Conductivity: capacity of a rock or sediment to transmit a

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