What is Hydrography?
[[File:Isobates-simple example.svg|thumb|Isobates to show depths of water basin.]]'''Hydrography''' is a subject of [[Geography]]. It concerns itself with measuring the physical characteristics of [[water]]s, such as [[river]]s, [[lake]]s and [[ocean]]s.<ref>[http://www.britannica.com/EBchecked/topic/278837/hydrography Britannica Online Encyclopedia]</ref> It can also be about such measurement in [[navigation|navigable]] waters, as they are necessary for the safe passage of [[ship]]s and [[vessel]]s. Massive hydrographical studies are usually undertaken by national or international organizations that sponsor [[Information|data]] collection through [[surveying|surveys]] and publication of [[chart]]s and descriptive materials for navigational purposes.<ref>{{Cite web |url=http://nhd.usgs.gov/ |title=National Hydrography Dataset |access-date=2011-03-11 |archive-date=2012-09-26 |archive-url=https://web.archive.org/web/20120926203427/http://nhd.usgs.gov/ |url-status=dead }}</ref> Hydrography's origin lies in the making of chart like drawings and notations made by individual [[Marine (military)|marine]]rs. It was usually a private [[property]], even closely held [[secret]]s, used for commercial or [[military]] advantage. ==Related pages== * [[Bathymetry]] * [[Cartography]] * [[Drought]] * [[Flood]] * [[Hydrology]] == Notes == {{reflist|2}} [[Category:Branches of geography]]