<descriptor thcode="2"><thesaurus thcode="2" name="USGS Thesaurus" scope="Topics and methods of scientific study carried out by USGS, with product types, scientific disciplines, geologic time, and types of institutional structure and activities.  Broad and shallow, used to help people find scientific information." creator="U.S. Geological Survey" rights="Public domain" edition="2.0" date="2020-01-09" codetype="number" prefix="topic" uri="https://www2.usgs.gov/science/USGSThesaurus" tblname="term" nonpref="nonpref" relterm="relterm" root_code="1" contact="pschweitzer"><category><term thcode="25" code="29" name="distinct labels" parent="26" scope="Preferred labels (descriptor texts) are distinct within the thesaurus. A concept can be specified either by its unique identifier (code) or by the text of its descriptor."/><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/><term thcode="25" code="13" name="transitive" parent="12" scope="Narrower terms have an &quot;is a&quot; relationship with their broader terms, and generally can be described as part-of, type-of, or instance-of the broader term."/><term thcode="25" code="21" name="disciplines" parent="2" scope="Broad categories of human inquiry or activity, such as scientific disciplines."/><term thcode="25" code="20" name="methods" parent="2" scope="Actions taken to obtain or analyze information"/><term thcode="25" code="19" name="organizational functions" parent="2" scope="Things that organizations do, typically including various types of programs, projects, and services."/><term thcode="25" code="7" name="temporal" parent="2" scope="Terms indicate periods of time, such as chronostratigraphic units, named historical periods or intervals surrounding known historical events, or seasons."/><term thcode="25" code="5" name="theme" parent="2" scope="Terms indicate domains of human concern, such as scientific discipline, societal problems, or characteristics of earth, space, oceans, and living things."/><term thcode="25" code="29" name="distinct labels" parent="26" scope="Preferred labels (descriptor texts) are distinct within the thesaurus. A concept can be specified either by its unique identifier (code) or by the text of its descriptor."/><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/><term thcode="25" code="13" name="transitive" parent="12" scope="Narrower terms have an &quot;is a&quot; relationship with their broader terms, and generally can be described as part-of, type-of, or instance-of the broader term."/><term thcode="25" code="21" name="disciplines" parent="2" scope="Broad categories of human inquiry or activity, such as scientific disciplines."/><term thcode="25" code="20" name="methods" parent="2" scope="Actions taken to obtain or analyze information"/><term thcode="25" code="19" name="organizational functions" parent="2" scope="Things that organizations do, typically including various types of programs, projects, and services."/><term thcode="25" code="7" name="temporal" parent="2" scope="Terms indicate periods of time, such as chronostratigraphic units, named historical periods or intervals surrounding known historical events, or seasons."/><term thcode="25" code="5" name="theme" parent="2" scope="Terms indicate domains of human concern, such as scientific discipline, societal problems, or characteristics of earth, space, oceans, and living things."/></category><altlabel><altlabel>USGSThesaurus</altlabel><altlabel>USGSThesaurus</altlabel></altlabel></thesaurus><term thcode="2" code="353" name="erosion" parent="451" scope="The process whereby materials of the earth's crust are loosened, dissolved, or worn away and simultaneously moved from one place to another."/><uf><usefor name="beach erosion"><usewith><term thcode="2" code="1799" name="coastal processes" parent="101" scope="Processes unique to coastal areas including longshore transport, beach erosion, storm surge, shoreline change, delta formation, barrier island migration, beach stabilization by vegetation"/></usewith></usefor><usefor name="coastal erosion"><usewith><term thcode="2" code="1799" name="coastal processes" parent="101" scope="Processes unique to coastal areas including longshore transport, beach erosion, storm surge, shoreline change, delta formation, barrier island migration, beach stabilization by vegetation"/></usewith></usefor><usefor name="dissolution"/><usefor name="shoreline erosion"><usewith><term thcode="2" code="1799" name="coastal processes" parent="101" scope="Processes unique to coastal areas including longshore transport, beach erosion, storm surge, shoreline change, delta formation, barrier island migration, beach stabilization by vegetation"/></usewith></usefor><usefor name="shoreline retreat"><usewith><term thcode="2" code="1799" name="coastal processes" parent="101" scope="Processes unique to coastal areas including longshore transport, beach erosion, storm surge, shoreline change, delta formation, barrier island migration, beach stabilization by vegetation"/></usewith></usefor><usefor name="wind erosion"><usewith><term thcode="2" code="1690" name="wind" parent="63" scope="Local air movements."/></usewith></usefor></uf><bt><term thcode="2" code="451" name="geologic processes" parent="101" scope="All types of processes involving geological structures."/><term thcode="2" code="101" name="biological and physical processes" parent="1174" scope="All continuing activities, functions, and phenomena associated with organisms and non-living matter."/><term thcode="2" code="1174" name="topics" parent="1" scope="Themes, subjects, and concerns for which USGS information resources are relevant."/><term thcode="2" code="1" name="Categories" scope="Thematic terms for categorizing information resources.  This thesaurus is intended to support finding and understanding scientific information."/></bt><nt><term thcode="2" code="1750" name="sinkhole formation" parent="353" scope="Localized collapse of the land surface usually due to erosion of the underlying materials.  Most commonly occurring in karst areas, but similar effects occur due to physical erosion in other terranes."/></nt><rt><term thcode="2" code="468" name="geomorphology" parent="464" scope="Branch of geology dealing with surface land features and the processes that create and change them."/><term thcode="2" code="484" name="glaciology" parent="291" scope="Science dealing with the features, origins, processes, and properties of snow, ice, glaciers, and ice sheets."/><term thcode="2" code="560" name="hydrology" parent="291" scope="Branch of earth science that deals with water as it occurs in the atmosphere, on the surface of the ground, and underground."/><term thcode="2" code="1687" name="scour" parent="1667" scope="Erosion of sediment in a stream bed, often occurring at manmade structures such as bridge supports."/><term thcode="2" code="1037" name="sedimentology" parent="464" scope="Branch of earth sciences concerned with the study of the origin, composition, transport, and changes of materials deposited by water, wind, or ice."/><term thcode="2" code="1318" name="watershed management" parent="776" scope="Controlling and directing the resources and activities associated with the land and streams of a drainage basin to maintain the supply and quality of water and prevent floods, erosions, and other destructive conditions."/></rt></descriptor>