GEOGRAPHY PAPER 1
Rivers
The drainage basin system
Hydrological cycle (water cycle) is an example
of a model. way water moves from sea,
through air onto land and back into sea. driven
by the suns heat and gravity.
drainage basin is part of hydrological cycle, operates once rain has fallen onto a
drainage basin. system as it has inputs, stores, flows and outputs. open system as
water and energy flow into, through and out, dynamic as system responds to its
change in inputs.
drainage basin is area of land drained by a river and its tributaries, supplies a river
with its water. one input (precipitation), two outputs (evapotranspiration and
channel flow), three flows (overland flow, through flow and groundwater flow).
flows operate at different speeds, flow’s balance determines how fast a river
responds to a rainfall input.
Components: precipitation; moisture in the atmosphere goes to the land (rain,
snow and hail). Interception; water lands on trees. Through fall; water drops off
leaves to ground. Stemflow; water runs down trunks/branches. Infiltration; surface
to soil. Overland flow; water flows over the ground surface e.g. if soil is
impermeable or saturated. Percolation; soil to rock.
Through flow; water moves back to sea through soil.
Groundwater; water moved through air spaces in the rock
back to the sea. Water table; level below which all the
airspaces in the rock are totally saturated with water.
Transpiration; vegetation to atmosphere.
Evapotranspiration; when water vapour returns to the
atmosphere by sun evaporating it/leaf transpiring. Channel
flow; water flows downhill towards sea as river discharge
Human activity
People need water for many purposes and amount of water in soil depends on
balance between precipitation and potential evapotranspiration.
Actual evapotranspiration: amount of water that leaves drainage basin in form of
water vapour going back to the atmosphere.
Potential evapotranspiration: amount of water that could go back to the
atmosphere if unlimited supply of soil moisture was available.
Water budget: balance between precipitation and potential evapotranspiration.
Used to manage water supply within a drainage basin. S = P - Q – E. S = soil
storage. P = precipitation. Q = channel flow out of the basin. E =
evapotranspiration.
Case study: Malaga in Southern Spain
on the costa del sol in southern Spain
Important tourist area, many small farms that produce fruit and veg for tourist
hotels and export
Farmers need enough water for crops to grow when crops are in great demand
Rivers
The drainage basin system
Hydrological cycle (water cycle) is an example
of a model. way water moves from sea,
through air onto land and back into sea. driven
by the suns heat and gravity.
drainage basin is part of hydrological cycle, operates once rain has fallen onto a
drainage basin. system as it has inputs, stores, flows and outputs. open system as
water and energy flow into, through and out, dynamic as system responds to its
change in inputs.
drainage basin is area of land drained by a river and its tributaries, supplies a river
with its water. one input (precipitation), two outputs (evapotranspiration and
channel flow), three flows (overland flow, through flow and groundwater flow).
flows operate at different speeds, flow’s balance determines how fast a river
responds to a rainfall input.
Components: precipitation; moisture in the atmosphere goes to the land (rain,
snow and hail). Interception; water lands on trees. Through fall; water drops off
leaves to ground. Stemflow; water runs down trunks/branches. Infiltration; surface
to soil. Overland flow; water flows over the ground surface e.g. if soil is
impermeable or saturated. Percolation; soil to rock.
Through flow; water moves back to sea through soil.
Groundwater; water moved through air spaces in the rock
back to the sea. Water table; level below which all the
airspaces in the rock are totally saturated with water.
Transpiration; vegetation to atmosphere.
Evapotranspiration; when water vapour returns to the
atmosphere by sun evaporating it/leaf transpiring. Channel
flow; water flows downhill towards sea as river discharge
Human activity
People need water for many purposes and amount of water in soil depends on
balance between precipitation and potential evapotranspiration.
Actual evapotranspiration: amount of water that leaves drainage basin in form of
water vapour going back to the atmosphere.
Potential evapotranspiration: amount of water that could go back to the
atmosphere if unlimited supply of soil moisture was available.
Water budget: balance between precipitation and potential evapotranspiration.
Used to manage water supply within a drainage basin. S = P - Q – E. S = soil
storage. P = precipitation. Q = channel flow out of the basin. E =
evapotranspiration.
Case study: Malaga in Southern Spain
on the costa del sol in southern Spain
Important tourist area, many small farms that produce fruit and veg for tourist
hotels and export
Farmers need enough water for crops to grow when crops are in great demand
