NATURAL RESOURCES 1. DEFINITION: Natural resources are the materials of nature that humans can use to meet their needs (eg food, clothing, housing, education, culture, recreation, etc.).. Natural resources are the source of raw materials (such as timber, minerals, oil, gas, coal, etc..), Transformed to produce goods used widely. 2.CLASSIFICATION: Natural resources are of many types and can be classified by their durability, divided into: RENEWABLE, where they can be exploited and non-renewable indefinitely: when finite and inexorable trend exhaustion. The revolving nature of a resource can be qualified: There are renewable resources that are by definition inexhaustible on a human scale, such as: or solar energy, or wind, or or tidal energy since, regardless of their intensive use, always available spontaneously. But among these there are some resources are exhaustible, whose availability depends on the degree of utilization of the same, since it sets the pace of recovery of the resource. or Among the latter are in inland water resources, either for direct consumption or for production of energy: dams can store only a finite amount of water depends on natural inputs to the watershed, which is renewed periodically, and which marks the maximum utilization rate to be reached before exhausting the appeal and have to stop using until recovery. or Something similar occurs with timber resources, as forests and forest plantations where the trees that are raw materials for construction and paper making, should not be exploited at a rate exceeding their regeneration capacity ( see forest management). Nonrenewable natural resources. They exist in the earth’s crust in finite quantities of these materials which can be exploited by man, this limited availability implies the need for material recycling systems, savings and alternatives to its use (especially for fuel, which can not be recycled) that do not compromise the development and quality of life of human societies. (See also Sustainable development). These are: or mineral resources, among which may also have or fossil fuels (coal or oil). Microsoft Encarta 2006. 1993-2005 Microsoft Corporation.All rights reserved.