RIVER NOTES
MATRIC IEB
GEOGRAPHY
,Drainage systems in South Africa Precipitation: water falls from atmospher
ground
The hydrological cycle
Percolation: movement of water slowly pa
soil bellow the surface
Infiltration: precipitation that soaks into s
Ground water: water that flows bellow the
the land
Surface runoff: water flowing over land . S
saturated and excess water from rain flow
Base flow: water entering stream from un
ground
Chanel flow: water in riverbed, from runof
infiltration
Discharge: volume of water which flows t
Water table: upper surface of zone of satu
underlying rocks
Transpiration: exhalation of water vapor t
leaves
, Water tables
Heavy rain Drought/little rainfall
Wet season
Dry season
Wet season
Dry season
Impermeable rock
Impermeable rock River channel doesn’t intersec
table therefore no base flow in
Water table rises after heavy rain.
Rain saturates soil, water table stream,
intersects with water table, base
flow into channel = high volume
, Runoff infiltration
Infiltration is
Precipitation that doesn’t
precipitation that
soak into the soil, instead
into the soil
moves on the earths
surface towards a stream
Factor High infiltration Low infiltration
Gradient GENTLE: more infiltration STEEP: more surface runoff, less in
Vegetation cover DENSE: slows water down= more infiltration SPARSE: allows for greater surface
less infiltration
MATRIC IEB
GEOGRAPHY
,Drainage systems in South Africa Precipitation: water falls from atmospher
ground
The hydrological cycle
Percolation: movement of water slowly pa
soil bellow the surface
Infiltration: precipitation that soaks into s
Ground water: water that flows bellow the
the land
Surface runoff: water flowing over land . S
saturated and excess water from rain flow
Base flow: water entering stream from un
ground
Chanel flow: water in riverbed, from runof
infiltration
Discharge: volume of water which flows t
Water table: upper surface of zone of satu
underlying rocks
Transpiration: exhalation of water vapor t
leaves
, Water tables
Heavy rain Drought/little rainfall
Wet season
Dry season
Wet season
Dry season
Impermeable rock
Impermeable rock River channel doesn’t intersec
table therefore no base flow in
Water table rises after heavy rain.
Rain saturates soil, water table stream,
intersects with water table, base
flow into channel = high volume
, Runoff infiltration
Infiltration is
Precipitation that doesn’t
precipitation that
soak into the soil, instead
into the soil
moves on the earths
surface towards a stream
Factor High infiltration Low infiltration
Gradient GENTLE: more infiltration STEEP: more surface runoff, less in
Vegetation cover DENSE: slows water down= more infiltration SPARSE: allows for greater surface
less infiltration
