CHAPTER 4: ABIOTIC SYSTEMS

Question 1

What is a soil series?

Answer 1

Group of soils originating from the same parent material with similar soil horizons, differing primarily in soil texture.

Each soil series is named for a nearby geographic feature, such as a town name, and can be divided into phases based on texture differences.

Question 2

Define soil horizon.

Answer 2

A layer parallel to the soil surface with differing physical, chemical, and biological characteristics from layers above and below.

Horizons are defined by physical features like color and texture.

Question 3

What is a soil profile?

Answer 3

A vertical section of soil through all its horizons extending into the parent material.

Question 4

What are the three types of soil textures?

Answer 4

• Sand: 0.05 to 2.0 mm in diameter
• Silt: 0.05 to 0.002 mm in diameter
• Clay: smaller than 0.002 mm in diameter

Question 5

What is soil porosity?

Answer 5

The measure of void spaces in soil and how soil particles are distributed.

Question 6

Define well-graded soil.

Answer 6

A soil with a wide range and even distribution of particle sizes where smaller particles fill voids created by larger grains.

Question 7

What is permeability in soil?

Answer 7

The rate at which water moves through soil.

Question 8

True or False: Hydric soils are characterized by prolonged saturation with water.

Answer 8

True

Question 9

What is bearing capacity?

Answer 9

A measure of soil’s ability to decrease in volume under pressure from a given weight.

Question 10

Define angle of repose.

Answer 10

The maximum slope at which loose material can be piled while remaining stable.

Question 11

What is soil elasticity?

Answer 11

The ability of soil to return to its original shape after being subjected to a load.

Question 12

What are the effects on erosion?

Answer 12

• Precipitation patterns
• Topography
• Soil disturbance
• Site location
• Natural disasters

Question 13

How can erosion be reduced?

Answer 13

• Preserve existing vegetation
• Reduce land disturbance
• Stabilize excavated areas
• Minimize disturbance to steep slopes
• Schedule clearing during dry season
• Introduce erosion control measures

Question 14

What is gully erosion?

Answer 14

Widening, deepening, and head cutting of small channels due to erosion.

Question 15

What are the components of soil fertility in the context of LARE?

Answer 15

• Nitrogen (N)
• Phosphorous (P)
• Potassium (K)

Question 16

What is the pH measurement range?

Answer 16

0-14

Question 17

What are alkaline soils characterized by?

Answer 17

High pH level and high amounts of calcium, magnesium, and sodium.

Question 18

To treat overly alkaline soil, _______ should be added.

Answer 18

sulfur

Question 19

What defines acidic soils?

Answer 19

Soils with a pH of less than 5.5, often resulting from fertilizers.

Question 20

To treat overly acidic soil, _______ should be added.

Answer 20

lime

Question 21

Define topography.

Answer 21

The physical features of a surface area, including elevations and the position of features.

Question 22

What does slope analysis help identify?

Answer 22

Steep and unbuildable slopes as well as potential locations for building sites.

Question 23

What is the aspect of a slope?

Answer 23

The direction the slope faces relative to the sun.

Question 24

What are the three types of streams based on flow?

Answer 24

• Ephemeral: flows only in response to precipitation
• Intermittent: flows part of the time
• Perennial: flows continuously

Question 25

What is a 100-year floodplain?

Answer 25

An area with a 1% chance of flooding in any given year.

Question 26

What is the purpose of FEMA maps?

Answer 26

To document floodplains and special hazard areas throughout the US.

Question 27

What are point sources of pollution?

Answer 27

Single identifiable sources of pollution from which pollutants are discharged.

Question 28

What is sedimentation?

Answer 28

The process by which soil particles are carried by water and deposited in rivers.

Question 29

Define aggradation.

Answer 29

A geological process where sediment builds up in a river, causing the riverbed to rise.

Question 30

What is the time of concentration in surface drainage?

Answer 30

The time needed for water to flow from the most remote point in a watershed to the outlet.

Question 31

What is the Rational Equation for peak discharge?

Answer 31

Q = ciA

Question 32

What are the benefits of a riparian zone?

Answer 32

* Groundwater recharge * Sediment stabilization * Flood attenuation * Water quality maintenance * Wildlife habitat

Question 33

What is freeboard in floodplain terminology?

Answer 33

Any portion of the flood in excess of the base flood elevation.

Question 34

What is biological growth in the context of environmental impact?

Answer 34

Increased turbidity, decreased flow capacity in streams/rivers, flooding in areas that never or rarely flooded in the past ## Footnote Examples include algal blooms.

Question 35

What is sedimentation?

Answer 35

The process by which soil particles are carried by flowing water and deposited in rivers, impacting water quality, river ecosystems, and navigation.

Question 36

Define aggradation.

Answer 36

A geological process when sediment builds up in a river, causing the riverbed to rise; also called alluviation.

Question 37

What characterizes a high water table?

Answer 37

Considered 'shallow,' contributes to storm surges and flooding, increases excavation costs due to waterproofing needs.

Question 38

What are the impacts of a high water table?

Answer 38

Affects on-site stormwater infiltration and the provision of septic systems.

Question 39

What is the consequence of excessive pumping of aquifer systems?

Answer 39

Can result in land subsidence and related ground failures.

Question 40

What are aquifer recharge areas?

Answer 40

Important locations to identify and protect from development.

Question 41

List the variables that compose climate.

Answer 41

* Temperature * Humidity * Wind * Precipitation (rain/snow) * Solar radiation

Question 42

What is the purpose of the USDA Plant Hardiness Zone Map?

Answer 42

Landscape architects consult the map to determine how climate interfaces with plant selection.

Question 43

What does Zone 1 represent on the USDA Plant Hardiness Zone Map?

Answer 43

The coldest zone.

Question 44

What does Zone 13 represent on the USDA Plant Hardiness Zone Map?

Answer 44

The hottest zone.

Question 45

Define albedo.

Answer 45

A measurement of an object's reflectivity, measuring the fraction of solar energy reflected from a surface back into space.

Question 46

What is the range of albedo values?

Answer 46

Albedo varies between 0 and 1.

Question 47

What does a low albedo indicate?

Answer 47

It means the surface absorbs more solar energy.

Question 48

What is the angle of incidence?

Answer 48

The angle at which a ray of light (usually the sun) hits a surface.

Question 49

What is azimuth?

Answer 49

The direction of a celestial object from the observer, expressed as the angular distance from the north or south point of the horizon.

Question 50

What is drainage wind?

Answer 50

A wind that blows from a higher elevation to a lower elevation.

Question 51

Define microclimate.

Answer 51

Differences in weather-related phenomena such as humidity, temperature, rainfall, and wind over a relatively small geographical area.

Question 52

How can winter winds be mitigated in landscape design?

Answer 52

By using windbreaks, such as trees.

Question 53

What can be done to reduce energy consumption for heating and cooling?

Answer 53

Through passive and active solar designs.

Question 54

What is the importance of sun/shade analysis in site design?

Answer 54

To mitigate solar radiation on a site design.

Question 55

In northern climates, how should outdoor spaces be designed in winter?

Answer 55

To receive sun for thermal comfort and prevent ice formation on pedestrian surfaces.

Question 56

What design strategies are suggested for desert regions?

Answer 56

Maximizing shade to protect users from heat.

Question 57

How can vertical elements influence site microclimate?

Answer 57

They can cast shadows.

Question 58

What role do fountains play in arid environments?

Answer 58

They can cool the air.

Question 59

What effect do dark colored paving materials have on temperature?

Answer 59

They absorb solar radiation and raise air temperature.

Question 60

What is a significant drawback of metal surfaces in landscape design?

Answer 60

They have temperature fluctuations and can become too hot or too cold.

Question 61

What is the benefit of large trees in landscape design?

Answer 61

They intercept solar radiation.

Question 62

How do plants influence air temperature?

Answer 62

They cool air temperatures through evapotranspiration.

Question 63

What is one way plants can improve air quality?

Answer 63

By removing chemical pollutants or capturing dust pollution.