4.Abiotic Systems Flashcards
Drainage basin/ watershed divides occur at _______
Ridges
Ridges (higher) point ________
Down
Valley (lower) points _____
Up
What is a slope’s aspect?
Direction/ orientation the slope faces relative toward the sun
In the winter months, which direction slope receives the most sun?
Southern
What direction aspect offer the most desirable microclimate?
Southeastern
Are north facing slopes colder or warmer than south facing slopes?
Colder
Which direction slope receive cold winter winds?
Northwestern
In the summer, which slope aspect is the hottest?
Western slope
What 3 factors does geology specific site inventory and analysis consider?
- Landforms
- Seismic hazards
- Depth to bedrock
T or F: the cost of excavating a cubic yard of rock is many times greater than the cost of excavating the same volume of soil
True
What are effects land development has on hydrological systems? (7)
- Increase rate and volume of storm water runoff
- Increased frequency and severity of flooding
- Reduced water quality
- Reduced infiltration and diminished aquifer recharge
- Reduced stream flow during dry weather
- Ecological degradation
- Reduced recreational opportunities on the water
Why can “channeling” engineered storm drain systems be harmful?
Can destroy ecological/ recreational benefits rivers/ streams had
What is time of concentration?
Amount of time needed for water to flow from most remote part of watershed to watershed outlet
Water always flows __________ to the direction of contour lines in a topo map
Perpendicular
What is the formula and purpose for the Rational Equation calculation?
Q = ciA
Determines rate of runoff
What does the Q stand for in the Rational Equation calculation?
Peak discharge measured as cubic ft/ sec
What does the “c” stand for in the Rational Equation calculation?
Runoff coefficient
What does the “I” stand for in the Rational Equation calculation?
Rainfall intensity measured in/hr
What does the “A” stand for in the Rational Equation calculation?
Drainage area measured in acres
What are some benefits to a riparian zone? (7)
- Groundwater recharge and discharge
- Sediment stabilization
- Flood attenuation
- Water quality maintenance
- Wildlife habitat
- Climate moderation
- Shoreline protection
What is a first order stream?
Primary drainage way at beginning of hydrological system
What is a second order stream?
Formed by confluence of two first-order streams
What are the 3 classifications given to streams and rivers?
Ephemeral, intermittent, and perennial
What is an ephemeral stream?
Stream that flows only in response to precipitation
What is an intermittent stream?
Stream that flows only part of the time or through only part of its reach
What is a perennial stream?
Stream that flows continuously
A 100 year floodplain means it has a ___% chance to flood each year
1%
What are the three areas that floodplains are composed of?
Channel, floodway, and flood fringe
This is the portion of a floodplain where a stream/ river flows under normal conditions
Channel
This is the portion of the floodplain that is used to convey floodwaters during a 100-yr flood
Floodway
This is the portion outside of the floodplain that usually contains slow moving or standing water
Flood fringe
This is often used to determine the height that living spaces must be constructed to be safe from a 100 year flood
Base flood elevation
Any portion of the flood in excess of the base flood elevation is called
Freeboard
Can buildings be created inside the boundaries of a floodplain?
No- only things that do not need erecting like golf courses, gardens, recreational use
What are 4 other ways you can determine the extents of a floodplain besides looking at a FEMA map?
- Topography
- Soils
- Vegetation types
- Extent of past flood flows
Any single identifiable source of pollution from which pollutants are discharged
Point source
Pollution caused by rainfall or snowmelt and absorbs natural/ human made pollutants and deposits the, into lakes, rivers, wetlands, groundwater, and the ocean
Non-point pollution
