Week 11, Lecture 3

Freshwater Availability

Less than 1% of the total water supply on Earth is freshwater.

Evaporation

Process by which liquid water is converted to vapor.

Precipitation

Water that falls to the Earth from the atmosphere in forms such as rain, snow, or hail.

Hydrologic Cycle

The continuous movement of water on, above, and below the surface of the Earth.

Aquifer

A porous layer of rock or sediment that holds water and allows it to flow.

Groundwater

Water located beneath the Earth's surface in soil pore spaces and in fractures of rock.

Wetlands

Areas where water covers the soil, either permanently or seasonally, and are crucial for ecosystems.

Land Subsidence

The sinking of the ground due to underground material movement, often caused by groundwater extraction.

Desalination

Process of removing salt from seawater to produce freshwater.

Embedded Water

Water that is used in the production of goods and services, even if not directly visible.

Water Scarcity

A situation where the demand for water exceeds the available supply or where there is insufficient safe water.

Virtual Water

The water required to produce a specific food or product, often referred to in discussions of trade and agriculture.

Surface Runoff

Water that flows over the ground surface and returns to bodies of water.

Streamflow

The flow of water in streams and rivers, critical for ecosystem health.

Infiltration

The process by which water enters the soil from the surface.

Transpiration

The process by which water is absorbed by plants and released into the atmosphere as vapor.

Sublimation

Transition of water directly from ice to vapor without becoming liquid.

Rain Shadow Effect

A region having little rainfall because it is sheltered from the prevailing rain-bearing winds.

Rain Shadow

A dry area on the side of a mountain away from the prevailing winds.

Zone of Saturation

The area underground where all spaces are filled with water.

Porous Layers

Layers of soil or rock that contain holes; they can hold water and facilitate aquifers.

Groundwater Flow

Movement of water through saturated zones of soil or rock.

Water Crisis

A situation where the available water resources are insufficient to meet demand or safe usage.