hydrology

Drainage basin

Area of land drained by a river and its tributaries

River discharge

Volume of water flowing in a river per second

Field capacity

Maximum water soil can hold after excess drains away

Infiltration excess

Rainfall intensity is greater than infiltration rates

Saturation overland flow

Soil is already full

Base flow

Slow movement of groundwater into a river channel

Water table

The boundary between the saturated water and the unsaturated ground

Groundwater recharge

Process where water infiltrates to replenish ground-water stores

Spring

Where ground naturally emerges at the surface

When does a spring occur? 2 points

Water table meets surface or impermeable rock forces the water out

Evapotranspiration

Evaporation and transportation from plants

Three factors affecting evaporation

Temperature, wind and vegetation

Formula for river discharge

Velocity x cross - sectional area

Surface storage examples - 3

Puddles, lakes and rivers

Overland flow

Water flowing over the land surface into a river

Channel flow

Water flowing within a river channel

Percolation

Downward moevemnt of water from soil to rock

Throughflow

Sideways movement of water through soil towards a river

Recharge

Process where water is added to groundwater storage

Factors affecting recharge - 3

Permeability of rock, rainfall intensity and vegetation cover