@prefix qudt: . @prefix owl: . @prefix ssd: . @prefix xsd: . @prefix skos: . @prefix rdfs: . @prefix qudt-unit: . @prefix qb: . @prefix dgu: . @prefix dct: . @prefix ui: . @prefix reg: . @prefix grib2-parameter: . @prefix qudt-quantity: . @prefix api: . @prefix vann: . @prefix prov: . @prefix foaf: . @prefix cc: . @prefix common-unit: . @prefix grib2-core: . @prefix void: . @prefix version: . @prefix bufr4-core: . @prefix rdf: . @prefix ldp: . @prefix time: . @prefix qudt-dimension: . @prefix vs: . @prefix dc: . @prefix common-core: . a skos:Concept ; rdfs:label "Non-recording gauge" ; dct:description "Determination of water stage by means of a non-recording gauge (e.g., graduated vertical or inclined staff gauge, wire-weight gauge, graduated rod, tape or point gauge and maximum-stage gauge). [Based on 'Non-recording gauges' in Guide to Hydrological Practices (WMO-No. 168), Volume I. 2008 edition, updated in 2020.]"@en ; skos:notation "421" . a skos:Concept ; rdfs:label "unknown" ; dct:description "The measurement/observing method is unknown."@en ; skos:notation "unknown" . a skos:Concept ; rdfs:label "Frequency domain reflectometry" ; dct:description "Measurement of soil capacitance by means of radio frequency waves. The soil acts as the dielectric completing a capacitance circuit, which is part of a feedback loop of a high-frequency transistor oscillator. [Based on 'Frequency domain reflectometry' in Guide to Hydrological Practices (WMO-No. 168), Volume I. 2008 edition, updated in 2020.]"@en ; skos:notation "419" . a skos:Concept ; rdfs:label "Flume" ; dct:description "Determination of the discharge of a stream by means of a man-made channel with clearly specified shape and dimensions. [Based on 'flume' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "362" . a skos:Concept ; rdfs:label "Volumetric method" ; dct:description "A process for measuring the discharge of a well, spring, or stream by diverting its flow into a volumetric container and timing the fill."@en ; skos:notation "375" . a skos:Concept ; rdfs:label "Gamma-ray attenuation" ; dct:description "Determination of gamma-ray attenuation at given depth of soil using a source and a detector placed at a given distance at the same depth. If the apparent dry bulk density of the soil is known the signal can be converted into a measure of the volumetric soil-moisture content. [Based on 'Gamma-ray attenuation' in Guide to Hydrological Practices (WMO-No. 168), Volume I. 2008 edition, updated in 2020.]"@en ; skos:notation "347" . a skos:Concept ; rdfs:label "Snow pillows and snow scales" ; dct:description "Weighing of snow-cover mass per unit area."@en ; skos:notation "262" . a skos:Concept ; rdfs:label "Recording gauge" ; dct:description "Determination of water stage by means of a recording gauge, for example, a device that automatically records the water level as detected by a sensor, either continuously or at regular time intervals. Synonyms: limnigraph, stage recorder, water-level recorder. [Based on 'water-level recorder' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "354" . a skos:Concept ; rdfs:label "Tensiometer" ; dct:description "Measurement of soil capillary tension by means of a porous cup, inserted in the soil, connected to a manometer by a water-filled tube. [Based on 'tensiometer' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "200" . a skos:Concept ; rdfs:label "Acoustic (ultrasonic) velocity meter" ; dct:description "Measurement of the difference in travel time of acoustic (ultrasonic) pulses between transducers in a stream to determine the mean velocity on the signal path. [Based on 'acoustic (ultrasonic) velocity meter' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "367" . a skos:Concept ; rdfs:label "Gamma-ray attenuation" ; dct:description "Determination of gamma-ray attenuation at given depth of soil using a source and a detector placed at a given distance at the same depth. If the apparent dry bulk density of the soil is known the signal can be converted into a measure of the volumetric soil-moisture content. [Based on 'Gamma-ray attenuation' in Guide to Hydrological Practices (WMO-No. 168), Volume I. 2008 edition, updated in 2020.]"@en ; skos:notation "420" . a skos:Concept ; rdfs:label "Measuring weir" ; dct:description "Determination of the discharge of a stream by means of a device or structure across the stream which causes a free or submerged fall. [Based on 'measuring weir' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "361" . a skos:Concept ; rdfs:label "Gravimetric moisture determination" ; dct:description "Measurement of the amount of water in soil by weighing a sample before and after drying it in an oven at a temperature of 100-110 degrees Celsius. [Based on 'gravimetric method' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "126" . a skos:Concept ; rdfs:label "Water discharge-bed material rating curve" ; dct:description "An empirical relationship relating bed-material discharge and streamflow based on correlation analysis of sediment samples and concurrent flow estimates and presented as a curve, table, or equation. [Based on 'sediment rating curve' in Guide to Hydrological Practices (WMO-No. 168), Volume I. 2008 edition, updated in 2020.]"@en ; skos:notation "374" . a skos:Concept ; rdfs:label "Frequency domain reflectometry" ; dct:description "Measurement of soil capacitance by means of radio frequency waves. The soil acts as the dielectric completing a capacitance circuit, which is part of a feedback loop of a high-frequency transistor oscillator. [Based on 'Frequency domain reflectometry' in Guide to Hydrological Practices (WMO-No. 168), Volume I. 2008 edition, updated in 2020.]"@en ; skos:notation "346" . a skos:Concept ; rdfs:label "Graduated device" ; dct:description "Manual measurement or observation made with a graduated fixed stake, a sturdy ruler, or an extendable graduated rod."@en ; skos:notation "261" . a skos:Concept ; rdfs:label "Dilution gauging" ; dct:description "Determination of the discharge of a stream by measuring the degree of dilution, caused by the flowing water, of an added tracer solution. Synonyms: chemical gauging, tracer dilution gauging. [Based on 'dilution gauging' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "359" . a skos:Concept ; rdfs:label "image velocimetry" ; dct:description "The measurement of velocities at the free surface of a moving water body using PIV (Particle Image Velocimetry) or LSPIV (Large Scale Particle Image Velocimetry) operates on the principle of statistical estimation of the displacement of groups of particles in consecutive images. The estimation is most-often made using cross-correlations applied to the spatial distribution of the light intensity defining the patterns (i.e., the pattern image) enclosed in small interrogation areas covering the whole image. The results of image processing is a velocity vector field centered on the interrogation area grid determined by dividing the estimated displacement with the time between images in the pair. Note: Given that LSPIV images cover large areas usually recorded from an oblique angle to the flow surface, an additional step is customarily involved, i.e. image orthorectification [Based on Aberle et al., Experimental Hydraulics: Instrumentation and Measurement Techniques, 2017 and Muste et al., Large-Scale Particle Image Velocimetry for Measurements in Riverine Environments, Special Issue on Hydrologic Measurements, Water Resources Research 44, 2008]."@en ; skos:notation "381" . a skos:Concept ; rdfs:label "Maximum-stage gauge" ; dct:description "Determination of the elevation of the flood crest by the adherence of regranulated cork to a graduated staff held in a fixed position with relation to the datum. [Based on 'maximum-stage gauge' in Guide to Hydrological Practices (WMO-No. 168), Volume I. 2008 edition, updated in 2020.]"@en ; skos:notation "353" . a skos:Concept ; rdfs:label "Electrical resistance blocks (Porous blocks)" ; dct:description "Determination of electrical resistance between two electrodes embedded in blocks of a porous material buried in the ground and in equilibrium with the surrounding moist soil. [Based on 'porous blocks/electrical resistance blocks' in Guide to Hydrological Practices (WMO-No. 168), Volume II. 2009 edition.]"@en ; skos:notation "187" . a skos:Concept ; rdfs:label "Neutron probe" ; dct:description "Measurement of the moisture content and hence the porosity of a geological formation by means of lowering a tool containing a radioactive element emitting neutrons and a neutron detector into a borehole. [Based on 'neutron logging' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "159" . a skos:Concept ; rdfs:label "Propeller-type current meter" ; dct:description "Determination of water velocity by means of a current meter in which the rotor is a propeller rotating around an axis parallel to the flow. [Based on 'propeller-type current meter' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "366" . a skos:Concept ; rdfs:label "radar water level gauge" ; dct:description "A radar water level gauge transmits microwave energy to measure the distance between the sensor and the water surface. The time it takes for the energy to reflect off the water surface and return to the radar is used to calculate the distance between the sensor and the water surface. Water level can then be determined from the elevation of the radar sensor and the sensor's measured distance to the water surface [Based on Skolnik et al, Radar Handbook, 3rd edition, 2008; Fulford et al, Testing and use of radar water level sensors by the U.S. Geological Survey, Manual on sea level: Measurement and interpretation Volume V: Radar gauges, 2016 and Fulford et al, Laboratory and field tests of the Sutron RLR-0003-1 water level sensor: U.S. Geological Survey Open-File Report, 2015]."@en ; skos:notation "379" . a skos:Concept ; rdfs:label "Slope-area method" ; dct:description "Determination of the discharge in a reach which is based on the surface slope, the reach roughness, the wetted perimeters and the flow areas of the various wetted cross-sections in the reach. [Based on 'slope-area method' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "360" . a skos:Concept ; rdfs:label "Soil thermometer" ; dct:description ""@en ; skos:notation "194" . a skos:Concept ; rdfs:label "Water discharge-sediment discharge rating curve" ; dct:description "An empirical relationship relating sediment discharge and streamflow based on correlation analysis of sediment samples and concurrent flow estimates and presented as a curve, table, or equation. [Based on 'sediment rating curve' in Guide to Hydrological Practices (WMO-No. 168), Volume I. 2008 edition, updated in 2020.]"@en ; skos:notation "373" . a skos:Concept ; rdfs:label "Echo sounding" ; dct:description "Evaluation of the return time of acoustic waves emitted into a medium to determine the distance between source and target. This method is used in hydrology, for example, to determine the depth of a water body. [Based on 'echo sounder' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "345" . a skos:Concept ; rdfs:label "Ultrasonic ranging" ; dct:description "Transmission of an ultrasonic pulse towards the target and listening for a return echo from that target."@en ; skos:notation "260" . a skos:Concept ; rdfs:label "Float gauging" ; dct:description "Measurement of the velocity of a stream by means of timing the downstream transit of a float or velocity rod. [International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "358" . a skos:Concept ; rdfs:label "radar velocimetry" ; dct:description "Radar velocimetry or surface velocity radar (radar sensor) is an active remote sensing method which measures the surface velocity of moving water. The radar sensor transmits microwave energy of a known frequency at an incidence angle (from nadir) to the water surface, where small-scale surface features such as waves shift the frequency of the microwave energy that is returned to the sensor. The frequency shift is used to compute the surface velocity of the water using the Doppler effect. Note: Because radar sensors measure the velocity at the water surface a transfer function, such as the probability concept, is needed to translate the surface velocity to a mean channel velocity [Based on Chiu, Entropy and probability concepts in hydraulics: J. Hydraul. Eng. 113, 1987; Fulton et al, Near-field remote sensing of surface velocity and river discharge using radars and the probability concept at 10 U.S. Geological Survey Streamgages, Remote Sens. 12, 2020; Fulton e al, Measuring Real-Time Streamflow Using Emerging Technologies: Radar, Hydroacoustics, and the Probability Concept, Journal of Hydrology 357, 2008 and Khan et al, Uncertainty in remote sensing of streams using noncontact radars, Journal of Hydrology 603, 2021]."@en ; skos:notation "380" . a skos:Concept ; rdfs:label "Point gauge" ; dct:description "Level measurement gauge, the essential element of which is a pointed rod that is lowered until it touches the water surface. [International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "352" . a skos:Concept ; rdfs:label "Cup-type current meter" ; dct:description "Determination of water velocity by means of a current meter whose rotor is composed of a wheel fitted with cups turning on a vertical axis. [Based on 'cup-type current meter' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "365" . a skos:Concept ; rdfs:label "Acoustic doppler velocity meter (ADVM)" ; dct:description "Determination of water velocity by using the Doppler principle applied to sound transmitted under water, in which the instrument is mounted in a fixed position under the water, giving an index velocity for a significant part of the flowing stream. [Based on Manual on Stream Gauging (WMO No. 1044), volume I]"@en ; skos:notation "378" . a skos:Concept ; rdfs:label "Displacement method of sediments" ; dct:description "Determination of sediment concentration by the measurement of the difference in weight between a sample of sediment-laden water and an equal volume of clear water at the same temperature. [Based on 'displacement method' in Manual on Sediment Management and Measurement (WMO-No. 948). 2003.]"@en ; skos:notation "372" . a skos:Concept ; rdfs:label "Laser ranging" ; dct:description "Emission of a modulated beam of light in the visible spectrum to determine the distance to a target by comparing the phase information from the reflected beam."@en ; skos:notation "344" . a skos:Concept ; rdfs:label "Velocity-area method" ; dct:description "Method of determining the discharge of a stream by measuring the width, velocity, and depth of the flowing water at a number of elemental areas, over the cross-section, and summing the products. [Based on 'velocity-area method' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "357" . a skos:Concept ; rdfs:label "Time domain reflectometry (TDR)" ; dct:description "Estimation of water content in unsaturated materials based on variations in their dielectric properties. [International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "203" . a skos:Concept ; rdfs:label "Wire-weight gauge" ; dct:description "Determination of water stage by means of a fine cable or wire attached to a weight which is lowered to the water surface in order to determine its position below a fixed above-surface point. [Based on 'wire weight gauge' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "351" . a reg:RegisterItem ; rdfs:label "Measurement/observing method (terrestrial and hydrological)" ; dct:dateAccepted "2020-04-29T14:36:18.471Z"^^xsd:dateTime ; dct:dateSubmitted "2019-10-14T16:36:37.95Z"^^xsd:dateTime ; dct:description "Measurement/observing method (terrestrial and hydrological)" ; dct:modified "2022-11-14T15:37:11.235Z"^^xsd:dateTime ; reg:definition [ reg:entity ; reg:entityVersion ] ; reg:itemClass skos:Collection , reg:Register , ldp:Container ; reg:notation "ObservingMethodTerrestrial" ; reg:register ; reg:status reg:statusStable ; reg:submitter [ foaf:accountName "https://api.github.com/users/kurt-hectic" ; foaf:name "kurt-hectic" ] ; owl:versionInfo 5 . a skos:Concept ; rdfs:label "Water current meter" ; dct:description "Determination of water velocity by means of a current meter, for example, an instrument for measuring water velocity. Synonym: flowmeter. [Based on 'current meter' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "364" . a skos:Concept ; rdfs:label "Stream index-velocity rating" ; dct:description "Computation of stream discharge based on a relation between stream index velocity and average velocity (index-velocity rating) and a relation between stage and cross-sectional area (stage-area rating). Given these ratings and concurrent observations of stream index velocity and stage, average velocity and area are computed and finally discharge as their product. [Based on Manual on Stream Gauging (WMO No. 1044), volume I]"@en ; skos:notation "377" . a skos:Concept ; rdfs:label "Staff gauge" ; dct:description "Determination of water stage by means of a graduated vertical scale, fixed to a staff or structure, on which the water level may be read. Synonym: vertical gauge. [Based on 'Staff gauge' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "349" . a skos:Concept ; rdfs:label "Gravimetric sediment measurement" ; dct:description "Estimation of the total sediment in a water sample by allowing the sediment to settle in a container, siphoning off the supernatant water, carefully transferring all the sediment from the container on to filter paper, then drying the sample and determining the mass of total sediment. [Based on 'gravimetric method' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "371" . a reg:Register , ldp:Container , skos:Collection ; rdfs:label "Measurement/observing method (terrestrial and hydrological)" ; dct:description "Measurement/observing method (terrestrial and hydrological)" ; dct:modified "2024-01-02T17:12:42.505Z"^^xsd:dateTime ; owl:versionInfo 49 ; skos:member , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ; ldp:hasMemberRelation skos:member . a skos:Concept ; rdfs:label "Pressure-actuated recording gauge" ; dct:description "Recording gauge operating on the principle that static pressure at a fixed point in the stream is directly proportional to the head of liquid above the point, i.e. the water level is proportional to the pressure difference between a fixed spot in the water column and the atmospheric pressure. [Based on 'Recording gauges' in Guide to Hydrological Practices (WMO-No. 168), Volume I. 2008 edition, updated in 2020.]"@en ; skos:notation "356" . a skos:Concept ; rdfs:label "Acoustic doppler current meter" ; dct:description "Determination of stream velocity by means of an acoustic Doppler instrument, which measures the velocity of the water based on the Doppler shift experienced by an acoustic pulse of energy which is reflected off particles suspended in, and moving with, the water. [Based on 'Acoustic Doppler Velocimeter' in Guide to Hydrological Practices (WMO-No. 168), Volume I. 2008 edition, updated in 2020.]"@en ; skos:notation "369" . a skos:Concept ; rdfs:label "Staff gauge" ; dct:description "Determination of water stage by means of a graduated vertical scale, fixed to a staff or structure, on which the water level may be read. Synonym: vertical gauge. [Based on 'Staff gauge' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "422" . a skos:Concept ; rdfs:label "Inclined gauge" ; dct:description "Determination of water stage by means of a non-vertical scale which is graduated to indicate vertical heights. [Based on 'inclined gauge' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "350" . a skos:Concept ; rdfs:label "inapplicable" ; dct:description "None of the codes in the table are applicable in the context of this particular observation."@en ; skos:notation "inapplicable" . a skos:Concept ; rdfs:label "Stage-discharge relation" ; dct:description "Determination of the discharge of a stream by means of a relationship between water level and discharge for a given cross-section, which may be expressed as a curve, a table or an equation. [Based on 'stage-discharge relation' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "363" . a skos:Concept ; rdfs:label "Soil heat flux plate" ; dct:description ""@en ; skos:notation "128" . a skos:Concept ; rdfs:label "Electromagnetic current meter" ; dct:description "Determination of water velocity based on the principle that a conductor (water) moving through a magnetic field will produce an electrical current directly proportional to the speed of movement (Faraday’s law). By measuring this current and the resultant distortion in the magnetic field the instrument can be calibrated to determine point velocities of flowing water. [Based on Manual on Stream Gauging (WMO-No. 1044), Volume I. 2010]"@en ; skos:notation "376" . a skos:Concept ; rdfs:label "Non-recording gauge" ; dct:description "Determination of water stage by means of a non-recording gauge (e.g., graduated vertical or inclined staff gauge, wire-weight gauge, graduated rod, tape or point gauge and maximum-stage gauge). [Based on 'Non-recording gauges' in Guide to Hydrological Practices (WMO-No. 168), Volume I. 2008 edition, updated in 2020.]"@en ; skos:notation "348" . a skos:Concept ; rdfs:label "Optical or nuclear suspended-sediment gauge" ; dct:description "Determination of the decrease of intensity of a visible light or X-rays beam by means of a photoelectric or nuclear detector situated at constant distance from the source of the beam. This decrease, caused by the scattering and/or absorption by suspended-sediment particles, is proportional to the sediment concentration, if other relevant characteristics of water and sediment (chemical, mineral composition, etc.) remain unchanged. [Based on 'photoelectric or nuclear suspended-sediment gauges' in Guide to Hydrological Practices (WMO-No. 168), Volume I. 2008 edition, updated in 2020.]"@en ; skos:notation "370" . a skos:Concept ; rdfs:label "Wire-float recording gauge (hydrograph)" ; dct:description "Determination of water stage by means of a gauge consisting of a float which rises and falls with changes in the water level; this movement being transmitted to a recording or indicating device. [Based on 'float gauge' in International Glossary of Hydrology (WMO-No. 385). 2012 edition.]"@en ; skos:notation "355" . a skos:Concept ; rdfs:label "Acoustic doppler current profiler (ADCP)" ; dct:description "An instrument that uses an acoustic doppler transducer to measure water velocity, depth and vessel path simultaneously and at various depths to compute discharge. The total discharge is computed from the profile information using matrix multiplication. [Based on 'Acoustic Doppler Current Profilers' in Guide to Hydrological Practices (WMO-No. 168), Volume I. 2008 edition, updated in 2020.]"@en ; skos:notation "368" .