@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 "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" .