{"thcode":2,"term":{"code":657,"name":"limnology","parent":291,"scope":"Scientific study of the physical and biological characteristics of inland bodies of water such as lakes and ponds."},"uf":[],"bt":[{"code":291,"name":"earth sciences","parent":1019,"scope":"Broad term for all science related to the study of the earth."},{"code":1019,"name":"sciences","parent":1,"scope":"Major educational fields, fields of study, and professional groupings within USGS."},{"code":1,"name":"Categories","parent":null,"scope":"Thematic terms for categorizing information resources.  This thesaurus is intended to support finding and understanding scientific information."}],"nt":[],"rt":[{"code":222,"name":"CTD measurement","parent":375,"scope":"Instrumental determination of conductivity, temperature, and pressure as a function of depth to determine the salinity of seawater."},{"code":54,"name":"aquatic ecosystems","parent":319,"scope":"Communities of interdependent organisms living primarily in or on water."},{"code":80,"name":"bathymetry","parent":1176,"scope":"The elevation of the earth's surface beneath a body of water, especially the ocean, typically determined by measurements of depth from the water surface."},{"code":85,"name":"benthic ecosystems","parent":54,"scope":"Biologic communities and habitats at the bottom of lakes, streams, or oceans."},{"code":359,"name":"eutrophication","parent":310,"scope":"The process by which water becomes enriched with plant nutrients, most commonly phosphorus and nitrogen."},{"code":419,"name":"freshwater ecosystems","parent":54,"scope":"Biological communities and habitats that exist in lakes, rivers, ponds, and other bodies of water that are not salty."},{"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."},{"code":1124,"name":"surface water (non-marine)","parent":1308,"scope":"Open bodies of water, such as lakes, rivers, or streams.  All non-marine waters on the  surface of the earth, including fresh, brackish, and salt water."},{"code":1125,"name":"surface water quality","parent":1306,"scope":"Chemical, physical, and biological characteristics of water in lakes, rivers, or streams related to its fitness for use."},{"code":1308,"name":"water resources","parent":777,"scope":"Stocks of water, the liquid derived from precipitation. A constituent of living matter and necessity for all life, it covers a large proportion of the earth's surface."}]}