Green belt land is a policy and land-use zone designation used in land-use planning to retain areas of largely undeveloped, wild, or agricultural land surrounding or neighboring urban areas. The primary purpose of green belt policy is to prevent urban sprawl by keeping land permanently open. Green belts are a buffer between towns and between town and countryside, and they encompass many different types and scales of landscapes such as wildlife corridors, streams, wetlands, and recreational parks as well as grazing lands, orchards, and vineyards. The objectives of green belt policy are to protect natural or semi-natural environments, improve air quality within urban areas, and provide recreational opportunities. Green belt lands are imperative to preserving local biodiversity and natural resources by offering space in the event of flooding to safeguard an already scarce water supply. The green belt designation is a planning tool, and the aim of green belt policy is to prevent urban sprawl by keeping land permanently open.