A watershed as used in geographical and hydrological terms is used to refer to the regions or a point on land within a given geographical region where drains off of the region as well as the water under it accumulates. This is mainly contributed by topography of the region as well as the gravity factor. The definition of a watershed is vividly and comprehensively delineated by John Wesley Powell as the point in any geographic region which is entirely bounded by water or hydrologic systems. From this hydrologic system there is interdependency and link of the living thing living around as they depend on the same water course (George, 1996).
As elaborated by the U.S. environmental protection agency, index of watershed indicators are elements which largely or highly depend to the watershed present within a given area. For instance, municipality council, schooling institutions, hospitals as well as other high water using institutions such as factories can be incorporated in the index of any given watershed. In the United States of America, these index watershed indicators are used to evaluate the number of people or other living things which are dependent on that given watershed, depletion rate as well as means of sustaining it. Consequently, these elements are the ones considered while calculating the index within a given area (Diane & Louis, 2007).
According to scientist as well as geographer’s studies, they have acknowledged that a watershed may take any form in terms of shape as well as size. Basing on the studies which have been carried out in the United States of America, they have shown that there are almost two thousand one hundred and ten watersheds in the United States of America geographic boundaries. In the Arizona regions of the United States of America, a number of geographic points or region such as Yuma, phoenix and Tucson have been identified to harbor or act as some watershed bases in the United States of America. Yuma is catalogued as 15030108 AZ as its index (EPA, 2011).
Diane E. Pataki., & Louis, P. (2007). Terrestrial ecosystems in a changing world, New York,
NY: Springer Publisher.
EPA. (2011). Surf your watershed. Retrieved on 3/5/2011 from
George, W. K. (1996). Carbon dioxide and terrestrial ecosystems, Oxford, UK: Academic