GEF

150 Glossary SILICON WAFER  A thin slice of semiconductor material used to make integrated circuits and some types of solar cells. SILTATION  Sedimentary deposits in a river, lake, or other body of water that cause it to become clogged; usually caused by soil erosion. SOCIAL MARKETING  A form of marketing that uses social science and psychology research to pro- mote behavior change around issues. SOFT PATH  An approach to sustainable water use which emphasizes intelligent resource management, conservation, stakeholder participation, and distrib- uted infrastructure over centralized infrastructure and management. SOLID  One of four main states of matter in which the molecules vibrate about fixed positions and can- not migrate to other positions in the substance. SOLVENT  A material that can dissolve and trans- port other substances. SPECIFIC HEAT CAPACITY  The amount of heat that is required to change the temperature of a sub- stance by a given amount. STAKEHOLDERS  Individuals or groups with a direct interest in a project, such as water management. SUBSIDY  Money granted by the government to assist an industry or business so that the price of a commodity or service may remain low or competitive. SURFACE IRRIGATION  The introduction and distri- bution of water over a surface, relying on gravity to deliver the water to plant roots. SURFACE RUNOFF  The flow of water over land surfaces that are saturated or impermeable. SURFACE TENSION  A cohesive force on the surface of liquids. SURFACE WATER  Water on the surface of the Earth in lakes, streams, and wetlands. SUSTAINABILITY  The long-termmaintenance of economic, environmental, and social health. SYSTEM-BASED APPROACH  A way of think- ing about sets of components or concepts on different scales. THERMAL POLLUTION  Raised water temperature due to power generation or other industrial activity. TRAGEDY OF THE COMMONS  A concept devel- oped by ecologist Garrett Hardin in which a common resource becomes degraded through the rational actions of individual users. TRANSPIRATION  The loss of water from the sur- faces of plants. TRIPLE BOTTOM LINE  A standard originating in the business world that gives equal weight to eco- nomics, the environment, and social equity. TROPHIC CASCADES  Systemic changes in an ecosystem resulting from a disruption such as the removal of a top predator. TURBIDITY  The level of suspended solids in a water body. UNIMPROVED WATER  Water that is not protected from outside contamination. URBAN STREAM SYNDROME  The decline in water quality in water bodies near urban development. URBANIZATION  The development of cities or other human infrastructure. USAID  The U.S. Agency for International Development is the government agency primarily responsible for administering civilian foreign aid. VALUE CHAIN  The full range of activities that busi- nesses go through to bring a product or service to their customers.