Lecture 3 -- The Physical Environment 2 Flashcards
What proportion of the earth’s surface is water? What proportion of the earth’s water is salty? What proportion of the earth’s water is neither salty nor glacier?
- Earth is 73% water, mostly salty.
- Oceans contain 97.1% and Glaciers contain 2.24%… so 97.1+2.24= 0.56% of earth’s water is neither salty not glacier
What is a rain shadow? Where is there one in Washington?
Rain shadows is a dry area on the leeward side of a mountainsous area (away from the wind). The mountains block the passage of rain-producing weather systems and cast a “shadow” of dryness behind them.
Eastern Washington, for example East of the Cascades there is a rain shadow effect
T/F: Everyone lives in a watershed.
TRUE
What’s the difference between surface flow and groundwater flow?
The difference between surface flow and groundwater flow is that groundwater is under the ground, in a shallow subsurface flow or deep groundwater storage. Surface flow is what the title sounds like, it is the water over the ground.
What is evapotranspiration and where does it occur in watersheds?
Evapotranspiration is the sum of evaporation and plant transpiration from the Earth’s land and ocean surface into the atmosphere.
What is hyporheic flow? Where, in a watershed, does it occur?
Hyporheic flow is when water from a river/channel moves into the spaces between rocks and gravel particles below and on the sides of a river. (A form of groundwater)
What is a hydrograph?
A hydrograph is a graph of water flow showing the rate of flow vs. time, past a specific point in a river or other channnel. Typically expressed in cubic meters or cubic feet per second.
What are the three main patterns of hydrology in NW rivers?
The three main dominant are
- Rain Dominant
- Transient Rain-Snow
- Snowment Dominant
How are the 3 river patterns in the PNW different from each other?
-Rain Dominant has a peak flow in early spring, when there is a lot of rain and snow in mountains starts to melt.
Transient Rain-Snow flow peaks early-mid summer. It made from increased amounts of rain during the spring and a lot of snow melt from heat of summer.
Snowmelt dominant peaks mid to late summer. By this time of the year the most snow melt that will happen has happened, thus the rivers are carrying all the excess water from the snow.
How is climate change expected to affect the hydrology in each of the three different types?
The only graph where future predictions are different from the historical trends is Transient Snow-Rain. The future prediction shows a shift in peak flow from late summer to late spring. This would be caused by the fast that as climate changes creates hotter temperature trends, winters will have less snow and what snow does happen will not stay frozen as long since springs are projected to be warmer.
Which is most sensitive to climate change?
Transient Rain-Snow
Why will each of the three types of rivers be affected differently by climate change?
Because they all involve a different type of water input. As the climage changes and as we experience warmer weather patterns this is disrupt typical rain and snow patterns for the PNW.
How does development affect the fate of water in a watershed? Compare and contrast the fate of water in a naturally vegetated watershed and an urban watershed.
Wayyy more Runoff
Less Shallow Infiltration
Wayy less deep infiltration
Less Evapotranspiration
How does storm water discharge differ between a forested and an agricultural area?
Forested areas: less overall discharge over a longer period of time
Argricultureal areas: more overall discharge over a shorter period
At the HJ Andrews Experimental Forest, a small watershed was clearcut and the changes in storm water hydrology were measured over several decades. For how many years did the total storm water volume and the storm peak flow remain higher than normal?
22 years
