อุทกศาสตร์

Also known as hydrographic survey, hydrographical survey

thumb|right|upright=1.3|Table of geography, hydrography, and navigation, from a 1728 Cyclopaedia, or an Universal Dictionary of Arts and Sciences|Cyclopaedia Hydrography is the branch of applied sciences which deals with the measurement and description of the physical features of oceans, seas, coastal areas, lakes and rivers, as well as with the prediction of their change over time, for the primary purpose of safety of navigation and in support of all other marine activities, including economic development, security and defense, scientific research, and environmental protection.