WATER - LANDSCAPES

Earths EXTERNAL PROCESS

weathering, mass wasting and erosion are called external process because they occur at or near earth's surface

Earths INTERNAL PROCESS

INTERNAL PROCESS such as: mountain building and volcanic activity derive their energy from earths interior

MASS WASTING (the work of gravity)

MASS WASTING is a downslope movement of rock and soil due to gravity

WATER - controls and triggers mass of wasting

(reduces internal resistance of materials and adds wight to a slope)

Water Cycle

The HYDROLOGIC CYCLE - a summary of the circulation of Earths water supply

Processes:

precipitation

evaporation

infiltration

runoff

transportation

RUNOFF

in EXTRENE RAINFALL EVENTS

-runoff depends on INTENSITY & DURATOIN of rainfall

-The amount of water already in the soild

-nature of the surface material

-slope of the land

-extent and type of vegetaion

RUNOFF - is an excess water after rainfall events

STREAMFLOW

The ability of stream to ERODE and TRANSPORT materials (determined by VELOCITY)

Factors that determine the velocity of STREAMFLOW

-gradient

-shape or size and roughness of channel

-volume of water in the channel

LONGITUDINAL PROFILE

-View along the LENGTH of a stream

-Viewed from the HEAD to the MOUTH of stream

Changes from UPSTREAM to DOWNSTREAM

PROFILE":

-a smooth concave curve aside from irregularities

-gradient decreases downstream

Factors that inceases downstream

-DISCHARGE

-CHANNEL SIZE

-VELOCITY

VELOCITY AND DISSCHARGE

the volume of water passing though a channel section per unit time is called FLOW RATE or DISCHARGE

TRANSPORT OF SEDIMENTS

transported material is called the streams load

-DISSOLVED LOAD

-SUSPENDED LOAD

-BED LOAD

what is CAPACITY in TRASNPORTING SEDIMENTS?

it is the max load a stream can transport

what is COMPETENCE in TRANSPORTING SEDIMENTS?

measure of a streams ability to transport particles based on size. indicates the maximum particle size a stream can transport and is determines by the streams velocity.

STREAM EROSION

lifting loosely consolidated particles by:

ABRASION AND DISSOLUTION

STRONGER CURRENTS LIFT PARTICLES MORE EFFECTIVELY

Deposition of sediment by a stream

-caused by a decrease in velocity

-competence is reduced

-sediment begins to drop out

Alluvium

STREAM SEDIMENTS (loose unconsolidated sediments, like clay silt sand)

BASE LEVEL

is the lowest point to which a stream can erode

2 types of base level: ULTIMATE & LOCAL OR TEMPORARY

DELTA

body of sediment where a stream enters a lake or ocean

NATURAL LEVEES

form parallel to the stream channel by successive floods over many years

BACK SWAMPS

poorly drained areas reslut in marshes or swamps

YAZOO TRIBUTARIES

a tributary stream that CANNOT enter a river due to blockage by levee

DRAINAGE PATTERN

DENDRITIC
RADIAL
RECTANGULAR
TRELLIS

FLOODS AND FLOOD CONTROL

floods are the most common and most destructive geological hazard

DISTRIBUTION OF GROUND WATER

ZONE OF AERATION

-unsaturated zone

-pore spaces in the material are filled mainly w air

Zone of saturation

all pores spaces in the material are filled with water

What is GROUNDWATER

it is water within the pores

water table

the upper limit of the zone of saturation

MOVEMENT OF GROUNDWATER

POROSITY - percentage of pore spaces

PERMEABILITY - ability to transmit water through connected pores

AQUITARD - an impermeable layer of material

AQUIFER - a permeable layer of material

WELLS

PUMPING OF WELLS CAN CAUSE A DRAWDOWN and CONE OF DEPRESSION