Environmental Geology - Exam 3

Front 1

_____ is an area where the surface runoff from precipitation onto the land and flows together toward lower areas such as lakes or oceans.

Back 1

Watershed (drainage basin)

Front 2

____ is the volume of water flowing past a specific point on the river per second.

Back 2

Discharge

Front 3

Discharge depends on the size of _____ and amount of ______.

Back 3

Watershed, participation

Front 4

Discharge (m 3/s) = ___ (m2) X ____ (m/s).

How streams respond to changes in the amount of water they carry

Back 4

Area, velocity

Front 5

______ is building roads; paved parking lots spreading across formerly vacant land (important in the Springfield area)

Back 5

Urbanization

Front 6

____ ___ flooding occurs as urbanization increases impermeable surface because rain water enters stream rather than soaking into the ground as it did prior to urbanization

Back 6

Hidden Valley

Front 7

_____ are plots of river discharge for heights in some cases over time.

Back 7

Hydrographs

Front 8

The highest point on the curve above flood stage represents flood ____.

Back 8

crest

Front 9

The _____ interval for an annual flood ranked 5 in the example of 1997-2006 period is 2 years - this flood level is reached or exceeded every two years on average.

Example:
2006-1997/5+1 =
9+1/5 =
10/5 =
2

*Big problem - this is a very short record

Back 9

reoccurance

Front 10

Flood probability = P=1/R1

A 100 year flood has a 1 in 100 chance (1%) of occurring in any given ____.

Back 10

year

Front 11

There is no meterological or statistical prohibition against ____ than one 100 year flood occurring in a century, or even a year

Back 11

more

Front 12

Whatever the cause, it is clear thatover the last 35 years the Chehaly River has produced more ___ ___ ____ than previously did.

Back 12

big time floods

Front 13

Urbanization, artificial leves and other human generated changes can alter the ___ and ___ of runoff and cause floods to become more common.

Back 13

amount, timing

Front 14

Storm surge flood, Galveston, TX reported ____ deaths, Sept. 1900.

Back 14

6,000

Front 15

____ ____ assesses stone stability, ratio of resisting force to driving force. More than 1 = close to being ____, 1.5 or 2 the resisting forces are much greater than the driving forces and the slope IS stable.

Back 15

Safety factor, stable

Front 16

Water content in slope materials affect stability in 2 ways:
1- increased water, increased weight, increases driving force= ___ likely slope failure will occur.
2 - increased water can _____ internal resisting forces.

Back 16

more, decrease

Front 17

If material becomes saturated the pressure of the water in the material (pore pressure) _____.

Back 17

increases

Front 18

Rising ___ _____ counteracts the driving force of gravity thus decreasing the resisting forces.

Back 18

pore pressure

Front 19

____ does NOT act like a lubricant. It is the pore pressures opposition to gravity.

Back 19

Water

Front 20

"___" means that more than half of the particles are larger than sand grains and the mixture has a consistency of wet concrete (debris flow)

Back 20

Coarse

Front 21

____ is a very slow type of earth flow that moves at a speed of one millimeter per year, driven by cycles of _____ and _____.

Back 21

Creep, freezing, thawing

Front 22

Gradual settling or sudden collapse of level or gently slopping land - _______.

Back 22

Subsidence

Front 23

____ - floods during high tides, the square floods (built in ____ land). Venice has ___ ___ 250+ days a year.

Back 23

Venice, swamp, aqua alta

Front 24

___ ___ is the onshore flow of water (storm surge) from the Atlantic Sea that coincides with high tides.

Back 24

Aqua alta

Front 25

The karst landscapes are characterized by ____, ____ and ____ that disappear below ground or suddenly appear as streams.

Back 25

sinkholes, caves, streams

Front 26

Natural causes of ___ ____ include above-normal rainfall, earthquakes, wildfires and slope steepening.

Back 26

slope failures

Front 27

Mitigating ____ ____ - avoid by living away from steep slopes, canyon bottoms and mouths for debris flows.

Back 27

debris flow

Front 28

The outlet of debris flow convergence structure are ___ ____ and ____ ____.

Back 28

debris basins, outlet walls

Front 29

____ ___ - sometimes this approach works, but often times the flows are so large that they over top the ____ and cover the houses below.

Back 29

Debris basins, basins