About Housing First. 1  According to the National Alliance to End Homelessness, Housing First is an approach to ending homelessness that centers on providing people experiencing homelessness with housing as quickly as possible â and then providing services as needed.
In human geography, a catchment area is the area from which a city, service or institution attracts a population that use their services. For example, a school catchment area is the geographic area from which students are eligible to attend a local school. Supermarkets, on the other hand, have a much lower density, with catchment areas of several neighborhoods (or several villages in rural areas). 2  This principle, similar to the central place theory, makes catchment areas an important area of study for geographers, economists, and urban planners.
A drainage basin or catchment basin is an extent or an area of land where surface water from rain, melting snow, or ice converges to a single point at a lower elevation, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean.he drainage basin includes both the streams and rivers that convey the water as well as the land surfaces from which water drains into those channels, and is separated from adjacent basins by a drainage divide.