2.1.2 - catchment hydrology and the drainage basin as a system

What is the drainage basin a subsystem of

The global hydrological cycle

Is the drainage basin an open or closed system

Open

What is the watershed

The boundary between two drainage basins

Drainage basin

Stores in a drainage basin

• groundwater

• Soil water

• Surface water

Flows in a drainage basin

• infiltration

• Overland flow

• Through flow

• Groundwater flow

• Percolation

Inputs in the drainage basin

Precipitation

Outputs in a drainage basin

• transpiration

• Evaporation

• Stream flow

Drainage basin as a system

What is through fall

Rainfall dripping from leaves and branches to the ground

What is stem flow

Water which flows to the ground via vegetation stems and trunks

What is infiltration

Water passing from the surface to the soil

What is through flow

Water that flows through the soil in a lateral movement via a matrix of pores

What is percolation

Water moves into the rock from the soil

What is ground water flow

The vertical and lateral movement of water through the drainage basin

What is overland flow

The movement of a sheet of water across the ground

On this graph where do you read the measurements from

• interception is read from 0

• Surface storage is read from interception

• Overland flow is read from surface storage