Data Layer 1 : Refers to data having similar characteristics being contained in the same plane or overlay (e.g., roads, rivers). Usually information contained in a data layer is related and is designed to be used with other layers
Association of Bay Area Governments (ABAG) - Regional Planning Agencies, Glossary of Terms, San Francisco, CA, USA 2003. http://www.abag.ca.gov/bayarea/eqmaps/eqfloods/fgl ossry.html, (ND/ Flood - Amer) {6}