Page 2281 - trc_centennial_deir201705

12.0 Glossary

Sky Glow (Light pollution): An adverse effect of manmade light. It is often used to denote
urban sky glow (brightening of the night sky due to man-made lighting) but also includes
glare (intense and blinding light), light trespass (light falling where it is not wanted or
needed; spill light), visual clutter, and other adverse effects of lighting (IDA 2005). In many
cases, sky glow is visible from great distances, particularly in evenings when there is
moisture in the air.

Sleep Interference: The capacity for noise to hamper normal sleep patterns.

Slide: A slide is a down slope movement of a soil or rock mass occurring dominantly on
shallower slopes at surfaces of rupture or on relatively thin zones of intense shear strain.
The displaced mass often slides beyond the toe of the surface rupture covering the original
ground surface of the slope. Slides consist of two main types: rotational and translational.
Rotational slides move along a surface of rupture that is curved and concave. Translational
slides move along a planar or undulating surface of rupture

Slope: Land gradient described as the vertical rise divided by the horizontal run, and
expressed in percent.

Slope Face: The slopes located directly below, or leading up to, the crest of a significant
ridgeline or prominent landform.

Slope Steepness: The relationship (the ratio) between the change in elevation (rise) and the
horizontal distance (run) over which that change in elevation occurs. The percent of
steepness of any given slope is determined by dividing the rise by the run on the natural
slope of land, multiplied by 100.

Sloughing/Sloughage: Shallow slides of loose or crumbling material.

Slump: Loosely consolidated materials or rock layers that move a short distance down a
slope leaving a concave scarp, or eroded face.

Smart Growth: A movement in urban and transportation planning that concentrates density
within central core areas of urban development. Smart Growth advocates compact, transit-
oriented, walkable, bicycle-friendly land uses, including mixed-use development with a
range of housing choices. It also advocates preservation of open space and many other
environmental amenities.

Smog: A combination of smoke and other particulates, ozone, hydrocarbons, nitrogen
oxides, and other chemically reactive compounds which, under certain conditions
of weather and sunlight, may result in a murky brown haze that causes adverse health
effects. The primary source of smog in California is motor vehicles.

Solar System, Active: A system using a mechanical device, such as a pump or a fan, and
energy in addition to solar energy to transport a conductive medium (air or water) between
a solar collector and the interior of a building for the purpose of heating or cooling.

R:\Projects\PAS\CEN\000306\Draft EIR\12.0_Glossary-051017.docx 12-73 Centennial Project
Draft EIR