18_groundwater_soil_09_post

18_groundwater_soil_09_post - oundwater, Soil: oundwater,...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: oundwater, Soil: oundwater, Soil: 1 18: Earths Resources 1-- Groundwater Springs, Marble Canyon, Grand Canyon National Park, Arizona. Photo: L. Ulrich U.S.: Groundwater source of most water used for drinking & irrigation oundwater, Soil: oundwater, Soil: 2 Importance of groundwater Table E.2 1% of all water on Earth is groundwater. Groundwater volume: 100x greater than lakes / rivers oundwater, Soil: oundwater, Soil: 3 Groundwater & Water Table Fig. 19.6 Water table Water table Unsaturated zone : pore (open) spaces partially filled with water. Saturated zone : all pore spaces filled with water. Water table : boundary between the unsaturated zone from the saturated zone Groundwater : water below water table. oundwater, Soil: oundwater, Soil: 4 Geometry of water table (WT) WT intersects ground surface at flowing streams, marshes, lakes & springs Elevation high, WT high Elevation high, WT high Elevation low, WT low Elevation low, WT low Fig. 19.7 WT height mimics ground-surface height. oundwater, Soil: oundwater, Soil: 5 Fig. 19.6 Geometry of water table (WT) Elevation of water table Elevation of water table changes with amount of changes with amount of precipitation. precipitation. Wet period Wet period Dry period Dry period oundwater, Soil: oundwater, Soil: 6 Groundwater volume Porosity Porosity : volume of : volume of pores in rock or pores in rock or sediment sediment Fig. 19.2 Porosity Porosity as as cementation cementation packing packing sorting sorting # of fractures # of fractures oundwater, Soil: oundwater, Soil: 7 Controls on groundwater volume Permeability Permeability : measure of ease with which : measure of ease with which water moves through ground water moves through ground Porosity: Porosity: moderate moderate Interconnectedness: Interconnectedness: none none Permeability: Permeability: none none Fig. 19.4 Porosity: Porosity: high high Interconnectedness: Interconnectedness: high high Permeability: Permeability: high high Porosity: Porosity: none none Permeability: Permeability: none none oundwater, Soil: oundwater, Soil: 8 Review Questions The sketch above that shows three samples of sandstone. The pore spaces (gray) between the sand grains (black) are completely filled in with cement. The long, white features are open fractures (cracks). Q1. Which rock ( A, B, or C ) has the greatest porosity? Q2. Which rock ( A, B, or C ) has the lowest porosity? Q3. Which rock ( A, B, or C ) has the greatest permeability? oundwater, Soil: oundwater, Soil: 9 Controls on groundwater volume Aquifer : porous, permeable unit that holds and releases water Fig. 19.5 Aquitard : nonporous or nonpermeable unit that does not transmit water oundwater, Soil: oundwater, Soil: 10 10 Controls on groundwater (GW) flow Groundwater flows from regions of high elevation to low elevation...
View Full Document

Page1 / 33

18_groundwater_soil_09_post - oundwater, Soil: oundwater,...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online