{"thcode":2,"term":{"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."},"uf":[{"name":"hydrologic maps","usewith":{"code":700,"name":"maps and atlases","parent":808,"scope":"Representation, usually on a flat surface, of a part or whole of the Earth or other parts of the universe.  Collections of maps linked digitally or bound together in a book are called atlases."}}],"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":[{"code":1678,"name":"hydrodynamics","parent":560,"scope":"Principles of fluid dynamics applied to water bodies."}],"rt":[{"code":278,"name":"domestic well water use","parent":1313,"scope":"Use of self-supplied water for household purposes, such as drinking, food preparation, bathing, washing clothes and dishes, flushing toilets, and watering lawns and gardens."},{"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."},{"code":398,"name":"floods","parent":1667,"scope":"Relatively high water that overflows the natural or artificial banks of a stream or coastal area that submerges land not normally below water level."},{"code":451,"name":"geologic processes","parent":101,"scope":"All types of processes involving geological structures."},{"code":518,"name":"groundwater quality","parent":1306,"scope":"Fitness of subsurface water for use based on its composition and properties."},{"code":554,"name":"hydrogeology","parent":464,"scope":"Study of subsurface waters and geologic aspects of surface waters."},{"code":562,"name":"hydrothermal processes","parent":451,"scope":"Natural phenomena relating to heated water generated by igneous activity."},{"code":581,"name":"industrial water use","parent":1313,"scope":"Use of water for industrial purposes such as fabrication, processing, washing, and cooling, and including such industries as steel, chemical and allied products, paper and allied products, mining, and petroleum refining."},{"code":607,"name":"irrigation","parent":1313,"scope":"Artificial application of water on lands to assist in the growing of crops and pastures or to maintain vegetative growth in recreational lands such as parks and golf courses."},{"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."},{"code":708,"name":"marine water quality","parent":1306,"scope":"Observed intrinsic characteristics of marine waters affecting their ability to support life or facilitate biological processes such as waste decomposition."},{"code":731,"name":"meteorology","parent":68,"scope":"Branch of science dealing with the short-term variations of atmospheric conditions including wind, precipitation, temperature, humidity, cloud cover, and air pressure."},{"code":751,"name":"mining water use","parent":1313,"scope":"Water use for the extraction of naturally occurring mineral deposits by mining or quarrying."},{"code":806,"name":"nutrient content (water)","parent":1304,"scope":"Contaminants in water that nourish organisms, especially plants. Includes nitrogen and phosphorus, either of which can lead to the harmful growth of algae and other plants when present to excess in a body of water."},{"code":818,"name":"ocean sciences","parent":291,"scope":"Sciences involved in the study of geological, biological, chemical, and physical characteristics and processes of the oceans."},{"code":854,"name":"oxygen content (water)","parent":1304,"scope":"Measurement of the concentration of oxygen dissolved in water, which is an important indicator of the condition of a water body."},{"code":925,"name":"power generation water use","parent":1313,"scope":"Use of water in the process of producing electric energy by transforming other forms of energy."},{"code":927,"name":"precipitation (atmospheric)","parent":63,"scope":"Any or all forms of water particles that fall from the atmosphere, such as rain, snow, hail and sleet."},{"code":1001,"name":"river reaches","parent":1002,"scope":"Continuous parts of streams between two specified points."},{"code":1002,"name":"river systems","parent":1124,"scope":"Long water courses including main streams and tributaries."},{"code":1010,"name":"salinity","parent":1304,"scope":"Measure of the concentration of salts dissolved in a solution."},{"code":1034,"name":"sediment transport","parent":451,"scope":"Transport of solid particles of unconsolidated rock and mineral fragments, chemical precipitates, or biological materials."},{"code":998,"name":"stream discharge","parent":1113,"scope":"Volume of water in a stream passing a given point at a given moment in time, expressed as a measure of volume per unit of time, i.e. cubic feet per second, million gallons per day, or gallons per minute."},{"code":1116,"name":"stream-gage measurement","parent":375,"scope":"Use of specialized instruments designed for observing, checking, and recording the water discharge that occurs in a natural channel."},{"code":1113,"name":"streamflow","parent":1667,"scope":"A type of channel flow, applied to a specific part of surface runoff in a stream, whether or not it is affected by diversion or regulation."},{"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":1129,"name":"suspended material (water)","parent":1304,"scope":"Sediment or organic material carried in suspension in the water column, in contrast to material that moves on or near the bottom. May be measured directly by sampling, or indirectly by acoustic or optical backscatter or transmission."},{"code":1295,"name":"wastewater discharge","parent":1311,"scope":"Water that is returned or reused after release from a wastewater treatment plant."},{"code":1299,"name":"water circulation","parent":1667,"scope":"The flow of water in a body of water due to wind or other forces or variations in density or temperature. Use 'water circulation' for situations that are not specifically covered by narrower terms. Use 'ocean circulation' for water circulation in the oceans."},{"code":1301,"name":"water hardness","parent":1304,"scope":"Indicator of the concentration of alkaline salts in water, mainly calcium and magnesium, as a measure of water quality."},{"code":1302,"name":"water pH","parent":1304,"scope":"The negative logarithm of the hydrogen ion concentration or activity of a water solution. Used for expressing both acidity (pH less than 7) and alkalinity (pH greater than 7), with 7 considered neutral."},{"code":1304,"name":"water properties","parent":1174,"scope":"Measurable physical and chemical characteristics of water from different sources."},{"code":1306,"name":"water quality","parent":1174,"scope":"The chemical, physical, and biological characteristics of water, usually in respect to its suitability for a particular purpose."},{"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."},{"code":1309,"name":"water sampling","parent":379,"scope":"Methods of collecting a representative part of a body of water for testing in controlled conditions."},{"code":1312,"name":"water temperature","parent":1304,"scope":"The degrees of heat of water from a given source at a specific time."},{"code":1313,"name":"water use","parent":1311,"scope":"Water withdrawal for a specific purpose, such as domestic use, irrigation, or industrial processing."},{"code":1327,"name":"wetland functions","parent":315,"scope":"Processes related to wetlands such as support of ecosystems, evaporation effects on weather, nutrient cycles, etc."}]}