Inflow

[edit] Introduction

As it relates to water, inflow can be defined as the water that enters another body of water. Inflow can be caused by flooding, surface water inflow and gains from groundwater. The opposite of inflow is outflow.

Inflow is typically associated with rivers which may have multiple inflow sources - typically with a single source acting as the predominant one. Inflow control measures (by way of pumps, valves or other devices) may be adopted to ensure that water levels do not exceed certain levels.

[edit] Calculation method

The term inflow can also be used to describe the average volume of incoming water - based on time elapsed. According to a 1978 Journal of Hydrology article by D. J. Gilbert, ‘Calculating lake inflow (note)’, "For small lakes it is not feasible to measure more than a small fraction of the inflow directly. The inflow, defined as gross inflow less surface evaporation and groundwater losses, can be obtained from the conservation of volume equation"

INFLOW = OUTFLOW + (LEVEL CHANGE) x AREA / (TIME STEP)

[edit] Other applications of the term

Other subject areas associated with the term inflow include finance/investment (as in cash flow), fire protection systems (as in airflow), availability of personnel (as in the movement of a large number of people) and dispersal of building materials other than water.

[edit] Related articles

• Groundwater control in urban areas.
• Hydrology.
• Hydropower.
• Sinkholes.
• Rain garden.
• River engineering.
• Tunnelling.

[edit] External resources

• DJ Gilbert, Journal of Hydrology, Calculating lake inflow (note).