Water Balance Flashcards

Flashcards covering key vocabulary and concepts related to water balance, runoff variation, hydrographs, and human impacts on the water cycle.

Water Balance

Inputs minus outputs in a drainage basin system; precipitation minus evaporation and transpiration.

Potential Evapotranspiration

The potential amount of evaporation or transpiration if there was sufficient water available.

Water Balance Equation

P = Q + PET +/- ΔS, where P is precipitation, Q is discharge, PET is potential evapotranspiration, and ΔS is the change in storage.

Soil Moisture Graph

A graph recording the amount of water held within soils throughout a year.

Soil Moisture Recharge

Period when precipitation is greater than evapotranspiration, replenishing soil water.

Discharge

The volume of water passing a measuring point in a given time within a river, measured in cubic meters per second.

River Regime

The variability in discharge over a year for a given river.

Storm Hydrograph (Flood Hydrograph)

A graph measuring the discharge of a river through a flood event.

Lag Time

The time between peak rainfall and peak discharge in a storm hydrograph.

Flashy Hydrograph

A hydrograph with a short lag time, indicating rapid flooding.

Rising Limb

The rising portion of a storm hydrograph.

Falling Limb

The falling portion of a storm hydrograph.

Base Flow

Normal discharge of the river during a flooding event, shown as a baseline on a hydrograph.

Water Abstraction

Removal of water from the ground for human use, such as drinking water.

Saline Intrusion

Seawater getting into the groundwater stores due to lowered water tables from over-abstraction.

Hydrosphere

All the water that is stored on or near the Earth's surface.