IB Geography Freshwater

Drainage Basin

an area within which water supplied by precipitation is transferred to the ocean, a lake, or larger stream.

Earth's Four Spheres

atmosphere, hydrosphere, lithosphere, biosphere

Atmosphere

the envelope of gases surrounding the earth or another planet.

Biosphere

Consists of all life on Earth and all parts of the Earth in which life exists, including land, water, and the atmosphere.

Hydrosphere

All the water at and near the surface of the earth, 97% of which is in oceans

Lithosphere

A rigid layer made up of the uppermost part of the mantle and the crust.

Cryosphere

A term referring to all water that is temporarily frozen in polar ice caps, snow, permafrost, and glaciers

Hydrological Cycle

cycle of water, the movement of water between the four spheres and its transformation between the gaseous (vapour), liquid, and solid forms.

open system

matter can enter from or escape to the surroundings

Tributary

a river or stream flowing into a larger river or lake.

Confluence

where a tributary joins the sea or a larger body of water

Delta

triangular area of marshland formed by deposits of silt at the mouth of some rivers

source

the place where a river begins

Watershed

Upper Course

the source area of a river, often in an upland or mountainous region. The upper course is steep and narrow, dominated by erosion and creating features like V-shaped valleys and waterfalls

Middle course

The area of a river between the source and the mouth. medium gradient, gently sloping valley sides, wider and deeper channel. The middle course is wider with a gentler slope, where lateral erosion forms meanders and the river's energy is focused on transportation

Lower course

This is the last section of a river's journey, here it is large and fast. The lower course is broad and flat, characterized by deposition and features such as floodplains, levees, and deltas as the river nears its mouth

River channel

The main path/course of the river.

Erosion

The process by which wind, water, ice, or gravity transports soil and sediment from one location to another

meander river

A meander is one of a series of regular sinuous curves, bends, loops, turns, or windings in the channel of a river, stream, or other watercourse.

oxbow lake

A meander that has been cut off from the river

permeable

Allowing liquids to pass through it.

porous

how much water material can hold

Input

Processes that introduce water into a system

Output

Processes that remove water from a system

Evaporation

The change of water (or a substance) from a liquid to a gas

Condensation

The change of state from a gas to a liquid

Melting

The change in state from a solid to a liquid

Freezing

The change of state from a liquid to a solid

Sublimation

A change directly from the solid to the gaseous state without becoming liquid

Precipitation

The conversion and transfer of moisture in the atmosphere to land

Infiltration

the process by which water on the ground surface enters the soil

infiltration capacity

the maximum rate at which soil can absorb water

Surface runoff (overland flow)

water that flows over the land's surface

Two ways surface runoff occurs

1. When precipitation exceeds infiltration rate
2. When soil is saturated (i.e. all the pore spaces are filled)

Throughflow

Water moving horizontally through the soil, due to gravity

Base flow (hydrograph)

Part of a river's discharge that is provided by groundwater seeping into the bed of a river.

discharge

the volume of water flowing past a certain point in a given amount of time.

Percolines

Lines of concentrated water flow between soil horizons.

stores

reservoirs where water is held

Flows/transfers

to the movement of water through various parts of the hydrological cycle.

Interception

Water retained by plant surfaces and which is later evaporated away or absorbed by the plant

Water retained by plant surfaces and which is later evaporated away or absorbed by the plant

water that either falls through gaps in the vegetation or which drops from leaves, twigs or stems.

Stemflow

water that trickles along twigs and branches and finally down the main trunk.

field capacity

the amount of soil moisture or water content held in the soil after excess water has drained away and the rate of downward movement has decreased.

wilting point

range of moisture content in which permanent wilting of plants occurs.

Aquifer

A body of rock or sediment that stores groundwater and allows the flow of groundwater.

Groundwater

Water that exists underground in saturated zones beneath the land surface. The upper surface of the saturated zone is called the water table

water table

The upper level of the saturated zone of groundwater

% Of Freshwater on Earth that's Groundwater?

96.5

recharge

the replenishment of an aquifer by the absorption of water.

Two main forces of water flow

1. Gravity
2. Frictional Resistance

turbulence

type of fluid motion characterized by chaotic changes in pressure and flow velocity.

Hydraulic radius

cross-sectional area of flow divided by the wetted perimeter

Corrasion (abrasion)

The process of a rivers' load crashing and rubbing into a rivers' banks and bed causing pieces to break off.

Hydraulic action

The force of air and water on the slides of rivers and cracks.

Corrosion (solution)

the removal of chemical ions, especially calcium

Flocculation

Flocculation

Bioconstruction

Vegetation increases the rate of deposition by slowing down the water

river discharge

the volume of water that flows through the river
measured in cubic meters per second (m3/sec)(cumecs)
discharge increases as u go down from upper course to lower course of river

discharge formula

Q= area•velocity
V= distance/time
A=length•depth(height)

river discharge impacted by:

-friction
-gravity:-speed

big channel + fast water=

high discharge

small channel + slow water=

low discharge

stream flow driven by:

•gravity: propels water forward
•frictional resistance:holds water back

types of streamflow

turbulent
laminar

turbulent

irregular movement of water
-causes erosion

laminar

water moves in smooth/parallel layers

-ex:groundwater

Stream flow is influenced by

• channel shape: V vs. U

• gradient: speed

• channel roughness: constitution of the underlying channel rock will impact the speed

Water’s velocity is

uneven

The efficiency of a channel’s shape is measured by the

hydraulic radius

Hydraulic radius

the ratio of the cross-sectional area divided by the wetted perimeter

Hydraulic radius equation

cross sectional area/ wetted perimeter

Cross Sectional Area

the area of a cross section of water flowing through a channel

Cross Sectional Area Equation

W x D

Wetted Perimeter

total length of the bed and bank sides in contact with the water channel

Wetted Perimeter Equation

A + B + C

A river flows that over _____ has to “work harder”

coarse material

Formula for channel roughness

V = R^2/3 S^1/2 n

R

hydraulic radius

s

channel slope (gradient)

n

boundary roughness (friction caused by urregularities i

Erosion

The process by which wind, water, ice, or gravity break down earthen materials & transport them to a new location.

Transportation

Movement of the eroded material from one place to another.

Deposition

Settling/dumping of the transported material.

Sediment Supply Zone

The upper course of the river can be considered the sediment supply zone.

Sediment Transfer Zone

The middle course can be considered the sediment transfer zone.

Deposition Zone

The lower course can be considered the deposition zone.

Attrition

Erodes the loads it’s carrying; particles bump into each other and get smaller.

Abrasion

Materials carried wear away the bed and banks; cause lateral and vertical erosion.

Hydraulic Action

Force of water can dislodge material.

Solution

Water in the channel reacts with rock in bed/bank to dissolve it.

Factors Impacting Rates of Erosion

Geology, Velocity, Load, Gradient, pH, Humans.

Suspension

Small particles remain suspended in the water.

Saltation

Particles too big to be carried via suspension 'hop down' the river bed.

Traction

Rocks & stones rolling along the river bed.

Dissolved Load

Material carried in solution. Common in calcareous rock.

River Capacity

Largest amount of sediment a river can transport at a specific course.

Hjulstrom Curve

Illustrates the relationship between flow velocity and the transport of sediment particles of different sizes.

X Axis of H Curve

Sediment particle size.