Hydrologic Cycle and Water Movement Concepts

HYDROLOGIC CYCLE

The process that describes how water moves through Earth's atmosphere, surface, and underground otherwise known as the WATER CYCLE. Water evaporates, rains, and flows, repeating in a cycle.

FLOWPATH

The path water takes through the environment.

PRECIPITATION

Water falling from the sky in forms like rain, snow, sleet, or hail.

EVAPORATION

Water turning from liquid to vapor (gas).

EVAPOTRANSPIRATION

The sum of all the processes by which water moves from surface to the atmosphere via evaporation and transpiration.

RUNOFF

Water that flows over land to rivers, lakes, and oceans (instead of soaking into the ground).

WATER TABLE

The boundary between the saturated and unsaturated zones.

SURFACE RUNOFF

Water flowing across the surface (rivers, streams, etc.) due to precipitation.

INTERCEPTION

The process of precipitation accumulating on vegetation and tree foliage.

DEPRESSION STORAGE

Water temporarily collecting in low areas (depressions) in the landscape.

INFILTRATION

Water soaking into the soil from the surface.

RECHARGE

Water replenishing the groundwater supply.

BASEFLOW

Slow, steady flow of water into rivers or streams from underground sources.

DISCHARGE

The quantity of water in a stream that passes a given point in a period of time.

UNSATURATED ZONE (VADOSE)

The area of soil and rock between the land's surface and the water table.

CAPILLARY FRINGE

The thin zone where water is pulled up from the saturated zone by capillary forces.

SATURATED ZONE (PHREATIC)

The underground layer completely filled with water.

SOIL

The top layer of the Earth's surface where plants grow.

REGOLITH

Loose material like soil or broken rock covering the bedrock.

BEDROCK

The foundation of the Earth's crust.

AQUIFER

An underground layer of sediment that stores and transmits water.

The traditional hydrologic cycle

The continuous movement of water on, above, and below the Earth's surface. It goes Evaporation → Condensation → Precipitation → Infiltration/Runoff → Recharge → Baseflow (ECPIRRB).

How do we know that water is moving in the subsurface?

We observe it through water flow and the movement of groundwater. We also see the changes in water levels using instruments like tracers.

What are the three important layers that water occurs in the subsurface?

1. Unsaturated Zone. 2) Saturated Zone and 3) The water Table.