piece of dust or other particle around which water condenses in the atmophere. These tiny droplets then collide and coalesce, with as many as 10,000 nuclei contributing to formation of a raindrop.

line connecting points of equal underwater depth.

biogeochemical cycle in which materials primarily are moved from land to sea and back again.

the ability to support and maintain balanced, integrated functionality in the natural habitat of a given region. The concept is applied primarily in drinking water management.

in hydraulics, a graphical representation of water depletion from storage stream channels, surface soil, and groundwater. A depletion curve can be drawn for base flow, direct runoff, or total flow.

a periodic thermal spring that results from the expansive force of super heated steam.

in sewage, suspended solids that will settle when the sewage is brought to a quiet state for a reasonable length of time, usually two hours.

an indented area in the land's surface, such a pit, pond, or lagoon.

feeding on or living in limestone.

soil area above the water table where water can rise up slightly through the cohesive force of capillary action. See phreatophytes