Condensation

The transformation of water vapor to liquid water droplets in the air, creating clouds and fog.

Deposition

Also known as desublimation, is a thermodynamic process, a phase transition in which gas (vapor) transforms into solid (ice).

Evaporation

The transformation of water from liquid to gas phases as it moves from the ground or bodies of water into the overlying atmosphere.

Percolation

Water flows horizontally through the soil and rocks under the influence of gravity.

Precipitation

Condensed water vapor that falls to the Earth’s surface. Most precipitation occurs as rain, but also includes snow, hail, fog drip, graupel, and sleet.

Interception

The water that is caught and stored by vegetation

Transpiration

The release of water vapor from plants and soil into the air. Water vapor is a gas that cannot be seen.

Infiltration

The process by which water soaks into the soil or is absorbed by the soil.

Base Flow

Even if it hasn’t rained for a while, there is always some groundwater that slowly seeps into rivers and lakes.

Stream Flow

The movement of water through natural channels of water

Advection

Advection is the horizontal movement of water vapor (or air masses) through the atmosphere, usually driven by wind.

Water Budget

A quantitative estimate of the amount of water in stores and flows of the water cycle

Inputs of Water

Precipitation, through flow in the soil, groundwater flow through rocks, overland flow and river flow, glacier melt

Outputs of Water

Evaporation, infiltration into the soil, percolation into the rocks, overflow during flooding and river outflow.

Storages of Water

Snow and ice, groundwater and aquifers, lakes and rivers, ocean, atmosphere, soil

Flows/transfers of Water

S&I: Precipitation over oceans G&A: precipitation over land O: surface runoff A: evapotranspiration from land S: evaporation from sea

Flow/transfer

The movement of energy or matter from one place to another within a system without changing form.

Transformation

When energy or matter changes for or state as it flows through a system

Transfer Water Cycle

surface runoff flooding infiltration percolation advection currents root absorption stream flow base flow precipitation

Transformation Water Cycle

sublimation freezing evapotranspiration evaporation condensation melting

Irrigation and Drip Irrigation

Irrigation can lead to excessive evaporation. Drip irrigation involves placing tubing with emitters on the ground alongside plants. Water drips slowly into the soil at the root level, making it more efficient and sustainable.

Runoff and excess fertilizer

If water is supplied faster than the soil can absorb, then it causes water to flow over the soil surface carrying nutrients, pesticides and other contaminants to other areas (e.g. rivers)

Soil Erosion

If the soil structure is not maintained by plant root systems or cover crops then soil can be eroded via surface runoff

Soil Compaction by Machinery

In industrial agriculture, large machinery compacts the soil, reducing soil pore space and thereby lowering the rate of water infiltration.

Urbanization on Water Systems

Water can’t infiltrate and be stored into the ground due to hard surfaces. Faster runoff = higher flood risk.

Deforestation on Water Systems

Trees store water in the canopy, branches and roots Evapotranspiration increase humidity and forms clouds Tree roots bind the soil and slow down infiltration reducing soil erosion and the risk of flooding