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<br />OOlH7 <br /> <br />GLOSSARY OF TERMS <br /> <br />Numerous technical terms or terms unique to this <br />study are used in this report. Some have a variety of <br />meanings or interpretations, even among water re- <br />source experts. The following definitions will be used <br />consistently throughout this report. <br />accounting unit - i'm area that is drained hy a river <br />system. a reach of a river and its tributaries in that <br />reach, a clos.ed basin, or a group of streams forming <br />a coastal drainage, as defined by the U.s. Water Re- <br />sources. Council. . <br />aquifer - a formation, group of formations, or a part <br />of a formation that contains sufficient saturated <br />permeable material to yield significant quantities of <br />water to wells ano. springs. <br />batch pracessing - a method of processing a quantity <br />of data in one operation. <br />cathod" ray tube (CRT) - a vacuum tube (television <br />screen) sometimes used to display output from a com- <br />puter system. <br />CIR adjustment factor - an adjustment in the crop <br />irrigation requirement made for drier than normal <br />years, since gurface water is generally limited in dry <br />years. The adjustment factor was used to reduce es- <br />timated irrigation depletions. <br />clear cut - a type of timber harvest in which all trees <br />within the timber gale boundary are cut. <br />computer - an electronic machine for performing cal- <br />culations. <br />computer program - instructions written in such a <br />manner that they can be interpreted by a computer. <br />computer system - computer equipment (hardware) <br />and computer programs (software) that are u;;ed to- <br />gether for jnput, processing, storage, and output of <br />information. <br />consumptive water use - a llse of water in which the <br />return flow available following use is less than the <br />amount of water supplied for use. Water is lost to the <br />system through evaporation, transpiration, or meta- <br />bolic processes. <br />contour farming - farming sloping land in such a way <br />that plowing, preparing land, planting. and cultivating <br />are done along the contour, not across it. <br />COnl1eyance efficiency - the volume of water delivered <br />to the farm, expressed as a ratio or percentage of the <br />volume of water diverted from a stream or other water <br />supply. Conveyance losses may include evaporation, <br />seepage, or leakage. <br />crop distribution pattern - t he proportional pattern, <br />by area, of the irrigated crops which comprise the total <br />amount of irrigated land in a node basin. A constant <br /> <br />crop distribution pattern, based on 1978 conditions, <br />was used througbout tbe entire study period. <br />crop irrigation requirement - the additional amount <br />of water, supplied by irrigation. needed to supplement <br />the eHective precipitation to adequately grow a given <br />crop to maturity. <br />data - factual material. <br />database - a collection of data stored as files that can <br />be retrieved by a computer s,ystem. <br />dcbu~ - to locate and correct errors in software. <br />depletion - a loss of water from a surface water system <br />as a result of man's activities. Such activities include, <br />but are not limited to: evaporation from man-made <br />reservoirs, transpiration from irrigated crops, metab- <br />olism from people and domestic animals, industrial <br />processes, and discharge to an aquifer resulting from <br />ground water use. <br />depletion swdy - a method of hydrological analysis <br />which estimates depletions and depleted streamflow" <br />throughout a specified period. Likely effects of future <br />projects or development can be assessed against past <br />hi!'tory of climatic, streamflow and development con- <br />ditions. <br />deplelvrs - a numher of persons, animals, irrigated <br />acres, industrial processes, or man-induced activities <br />that causes a depletion. given in numhers per year. <br />diversion requirement - that quantity of surface water <br />10 be diverted from a stream to satisfy the crop irri- <br />15ation requirement and conveyance losses for all full <br />service, partial service, or waterspreader irrigfltion in <br />a node basin. <br />effeclive precipitation - that portion of the total pre- <br />cipitation which jg available to a plant for use in its <br />physiological processes: losses occur due to evapora- <br />tion, surface runoff, and deep percolation beyond the <br />root zone. <br />equ.ivafr.nt clear-cut area - a data transformation pa- <br />rameter used in assessing tbe hydrologic effects of par- <br />t ial cuts and road building. Hydrologic effects were <br />estimated for clear.cut areas with the effects ofpart.ial <br />cut and road building then being assessed in compar- <br />ison to that of clear-cuts. It was assumed that one acre <br />of part ial cnt wag equivalent to 0.4. acres of clear-cut., <br />and that one mile of road construction was the equiv- <br />alent of six clear-cut acres. <br />evapotranspiration - the process of converting water <br />on the earth's surface to atmospheric water vapor, by <br />either e\'aporation or transpiration. <br />[arm ponds - small impoundments or dugouts of less <br />than 40 acres surface area used primarily for livestock <br />water. <br /> <br />9 <br />