NR 435 Chapter 10

Porous, water-bearing layers of sand, gravel and rock below the earth's surface; reservoirs for groundwater.

Biochemical compound

The water lost from the system throgh evaporation, absorbtion or contamination.

Rivers and lakes rich in organic material.

The amont of material transferred between compartments per unit time.

Water held in gravel deposits or porous roch below the earth's surface.

The natural process by which water is purified and made fresh through evaporation and precipitation.

The process of water percolation into the soil and pores and hollow permeable rocks.

Condition of rivers and lakes that have clear water and low biological productivity.

Decline in oxygen downstream from a pollution source that introduces materials with high biological oxygen demands.

The evaporation of water from plant surfaces, especially throught stomates.

The length of time a component, such as an individual water molecule, spends in a particular process or cycle.

The excess of precipitation over evaporation; the main source of surface water and in broad terms, the water available for human use.

All the land drained by a stream or river.

The top layer of the zone of saturation.

The total amount of water taken from a water supply.

Upper soil layers that hold both air and water.

Lower soil layers where all spaces are filled with water.