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1、BRITISH STANDARD BS 7562-1: 1992 Planning, design and installation of irrigation schemes Part 1: Glossary of terms Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 10:17:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7562-1:1992 This British Standard, having be
2、en prepared under the direction of the Agricultural Machinery and Implements Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on 1 April 1992 BSI 07-1999 The following BSI references relate to the work on this standard: Committee reference AG
3、E/30 Draft for comment 87/73202 DC ISBN 0 580 20554 1 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Agricultural Machinery and Implements Standards Policy Committee (AGE/-) to Technical Committee AGE/30, upon which the following bodies
4、 were represented: Agricultural Engineers Association British Agricultural and Garden Machinery Association Ltd. Health and Safety Executive Ministry of Agriculture, Fisheries and Food National Farmers Union Silsoe College Silsoe Research Institute UK Irrigation Association Water Services Associatio
5、n of England and Wales Well Drillers Association Amendments issued since publication Amd. No.DateComments Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 10:17:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7562-1:1992 BSI 07-1999i Contents Page Committees res
6、ponsibleInside front cover Forewordii 1Scope1 Section 1 Basic terms1 Section 2 Site data and water resource terms3 Section 3 Distribution terms17 Section 4 Implementation terms24 Index26 Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 10:17:41 GMT+00:00 2006, Un
7、controlled Copy, (c) BSI BS 7562-1:1992 ii BSI 07-1999 Foreword This Part of BS 7562 has been prepared under the direction of the Agricultural Machinery and Implements Standards Policy Committee and is a glossary to a series of Parts containing recommendations on good practice in the planning, desig
8、n and installation of irrigation schemes together with information and guidance. BS 7562 is intended for the use of engineers and farmers having some knowledge of the subject. It embodies the experience of engineers successfully engaged on the design and construction of irrigation schemes so that ot
9、her reasonably qualified engineers may use it as a basis for the design of similar irrigation schemes. The other Parts of BS 7562 are written as codes of practice. A code of practice represents good practice at the time it is written and, inevitably, technical developments may render parts of it obs
10、olescent in time. It is the responsibility of engineers concerned with the design and construction of schemes to remain conversant with developments in good practice, which have taken place since publication of the code. The six Parts of BS 7562 are as follows. Part 1: Glossary of terms; Part 2: Cod
11、e of practice for acquisition of site data1); Part 3: Code of practice for irrigation water requirements1); Part 4: Code of practice for water resources1); Part 5: Code of practice for distribution systems and irrigation equipment1); Part 6: Code of practice for implementation procedures1). A Britis
12、h Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front
13、cover, an inside front cover, pages i and ii, pages 1 to 27 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. 1) In preparation. Licensed Copy: London South Bank Uni
14、versity, London South Bank University, Fri Dec 08 10:17:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7562-1:1992 BSI 07-19991 1 Scope This Part of BS 7562 gives a glossary of terms used in the planning, design and installation of irrigation systems. Units of measurement are generally quoted in S
15、I units. No.TermDefinition Section 1. Basic terms 1 01actual crop evapotranspiration ETa (crop) Rate of evapotranspiration equal to, or smaller than, predicted ET crop as affected by the level of available soil water, salinity, field size, or other causes; mm/day. 1 02agriculturally effective rainfa
16、llRainfall available for plant growth. 1 03allowable soil water depletionDepth of water in the root zone readily available to the crop for given soil and climate, allowing unrestricted evapotranspiration as the fraction p of total available soil water between field capacity and wilting point; mm/m s
17、oil depth. 1 04available water capacity (AWC)The soil water which is available or can be taken up by plants at any moisture content between field capacity and permanent wilting point; mm. NOTESandy soils contain less available water than clay soils and loams form an intermediate group. 1 05average a
18、nnual rainfallFor a specified place, the average annual value for rainfall is the mean of the annual amounts over the period for which rainfall statistics are available. In the UK the period seldom exceeds 40 years; mm. 1 06cappingThe formation of a crust on a soil, often during a hot, dry spell, us
19、ually after heavy rain which causes the surface soil particles to break down, blocking up the soil pores. 1 07crop coefficient/factorRatio between crop evapotranspiration and the reference crop evapotranspiration (ETr); mm/day. 1 08depth of irrigation, dGross depth of water discharged by irrigation
20、system (including application losses). 1 09effective groundcoverPercentage of ground covered by the crop when ET crop is approaching maximum, generally 70 % to 80 % of surface area. 1 10effective rooting depthSoil depth from which the full-grown crop extracts most of the water needed for evapotransp
21、iration; mm. 1 11field capacityThe maximum possible amount of water held by a soil allowing for free drainage; mm/m. NOTEFor example, the field water content of soil 2 days or 3 days after heavy rain or irrigation. 1 12infiltration rateThe rate at which water is absorbed, or seeps into or through th
22、e interstices of a soil or other porous material; mm/h. a) initial infiltration rate. The rate at which the water enters the soil at the beginning of water application to the soil. b) instantaneous infiltration rate. The rate at which water enters the soil at a specific point in time. c) average inf
23、iltration rate. Rate of infiltration of water into the soil. The total depth of water applied divided by the time during which the water is applied. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 10:17:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7562-1:199
24、2 2 BSI 07-1999 No.TermDefinition d) final infiltration rate. Rate at which water will enter the soil when, after initial wetting of the soil, the rate becomes essentially constant. 1 13net irrigation requirementDepth of water required for meeting evapotranspiration minus contribution by precipitati
25、on, groundwater, stored soil water. This does not include operation losses and leaching requirements; mm/period. 1 14potential crop evapotranspiration ET(crop) Rate of evapotranspiration of a disease-free crop growing in a large field under optimal soil conditions, including water and fertilizer. In
26、cludes water loss through transpiration by vegetation and evaporation from the soil surface and wet leaves; mm. 1 15readily available moistureThe volume of moisture held in a soil that can be extracted without moisture stress. 1 16reference crop evapotranspiration (ETr) Rate of evapotranspiration fr
27、om an extended surface of 8 mm to 15 mm tall, green grass cover of uniform height, actively growing, completely shading the ground and not short of water; mm/day. 1 17soil structureThe arrangement of individual soil particles and aggregates. 1 18soil water tensionForce at which water is held by the
28、soil or negative pressure or suction that has to be applied to bring the water in a porous cup into static equilibrium with the water in the soil. 1 19wilting pointa) permanent wilting point. The stage when a soil is so dry that plant roots are permanently unable to extract water at a rate sufficien
29、t to maintain turgidity. NOTEAt this stage, transpiration almost ceases, the plants wilt, and the plant is said to be at permanent wilting point. b) temporary wilting point. The stage when available soil water is reduced to the point where the rate at which the plant extracts available soil water is
30、 less than ET crop even though the soil moisture may be plentiful. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 10:17:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7562-1:1992 BSI 07-19993 No.TermDefinition Section 2. Site data and water resource terms 2 0
31、1acidHaving a pH value of less than 7.0. 2 02acidificationThe use of acid, usually hydrochloric, to increase the water supply from a borehole which is failing owing to encrustations on screens and slotted pipes. It may also be used to improve the yield from bores in chalk or limestone by enlarging t
32、he fissures. 2 03air-lift pumpAn appliance for lifting water in a well or sump. It consists of an air compressor at the surface and two pipes hanging vertically, with one pipe perhaps within the other. The smaller pipe delivers compressed air to the depth at which water occurs. At this point a nozzl
33、e discharges the air into the free water and, by aerating it, causes its density to drop. This mixture of water and air is then forced upwards by the head of groundwater. 2 04air-pumpingLifting water from a well using compressed air to aerate the water so that the air-water mixture will rise to the
34、surface. 2 05alkalineHaving a pH value above 7.0. 2 06alluviation (or aggradation)The deposition or building-up of sediments by stream or water action, particularly along rivers and estuaries where flow is retarded. 2 07angle of reposeThe maximum slope, measured from the horizontal, at which rocks,
35、soils, and loose material on the banks of canals, rivers, dams, or embankments remain stable. 2 08angle of slideThe angle (measured in degrees from the horizontal) of the sloping sides of a canal, reservoir, or other cutting, at which a landslide will start. The angle varies considerably and the wat
36、er content has a major influence. 2 09annular spaceThe space or cavity between the outside of the borehole casing and the surrounding ground. 2 10apronA hard floor or surface to the bed or banks of a river or canal, or below chutes, spillways, groynes or the toes of dams, to minimize scour. It may c
37、onsist of begwark, mattress, timber, mass concrete, riprap, or preferably reinforced concrete. 2 11aquiferA relatively permeable or fissured deposit which yields useful supplies of water when tapped by a well. 2 12area of influence (well)The surface area around a well or borehole with the same horiz
38、ontal extent as that part of the underlying water-table that is lowered by pumping from the well at a given rate of discharge. 2 13artesian aquiferA confined aquifer in which the water is under sufficient pressure to cause water to rise above ground level. 2 14artesian boreholeA borehole which penet
39、rates an artesian aquifer and in which the water level rises above ground level. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 10:17:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7562-1:1992 4 BSI 07-1999 No.TermDefinition 2 15artificial rechargeAugmenting
40、the natural infiltration of surface water or rainfall into underground rocks or channels. The recharge may be by spreading of water, by changing the natural conditions, by some form of construction or by putting down wells. 2 16artificial recharge of aquifer (or groundwater increment or groundwater
41、recharge) The introduction of surface water, such as streams and rainfall, into underground storage. 2 17backblowingA method of improving the water yield from boreholes, particularly in fissured rocks. It is not unlike swabbing in action and is sometimes more effective. It employs compressed air (a)
42、 for pumping in the bore by air lift, or (b) by pumping in air (when the top of the hole is sealed) until the maximum pressure is obtained and then releasing it suddenly. 2 18backwashThe back flow of water which follows the breaking of a wave; it scours and carries the finer material towards deeper
43、water where it is temporarily deposited. 2 19bafflesA series of plates, vanes or guides set in a channel or conduit to secure more uniform flow conditions by damping eddies. 2 20bailerA tool used in drilling for removing sludge, mud or sand from a borehole. It consists of a steel tube with an open e
44、nd, the other being either closed or fitted with a simple valve. 2 21balanced earthworksEarthworks in which the “cuts” equal the “fills”. The ideal is not easily achieved but is a target when planning the layout of trenches, water supply channels, and other hydraulic works. 2 22base flowThe sustaine
45、d flow of streams from snow and glaciers (not normal in the UK) or from underground storage and not related to direct runoff. NOTESustained flow resulting from drainage of large lakes or springs or other outflow of groundwater, as opposed to surface runoff. 2 23batteringThe artificial sloping bank o
46、f a river or other bank to a flatter grade to reduce caving or collapse of the earth. The procedure is often allowed by beaching with stone or by grassing or other vegetation to bind the soil layers. 2 24beachingA layer of stones for revetting below the level of stone pitching a reservoir or embankm
47、ent: the layer is from 0.3 m to 0.6 m thick and stone size from 75 mm to 200 mm. Also applied to a layer of stones of about 150 mm diameter to prevent scour due to wave action. 2 25bed loadThe weight or volume of boulders, pebbles, and gravel rolled or moved by a stream along its bed in unit time. 2
48、 26bed scourThe wearing away of the rock, soil, or deposited material from the bed of a river by flowing water or waves. 2 27bed slopeThe inclination of the bed of a stream along its course given as difference in elevation per unit of horizontal distance. Licensed Copy: London South Bank University,
49、 London South Bank University, Fri Dec 08 10:17:41 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7562-1:1992 BSI 07-19995 No.TermDefinition 2 28bentoniteA very fine clay substance with a maximum particle size of 2 m; has a very high swelling property when moistened. Used in reservoirs, ponds, irrigation and water supply channels, and in small farm dams to reduce seepage. 2 29blow outA failure due to tunnelling or piping in earth dams or channels. 2 30boilThe seepage or inflow of water and fine sand or silt at the bottom of an excavation due to a high exter