節(jié)水灌溉外文翻譯

1、本科畢業(yè)（設(shè)計(jì)）論文外文文獻(xiàn)翻譯學(xué) 院： 城鄉(xiāng)建設(shè)學(xué)院 專業(yè)班級(jí)： 農(nóng)業(yè)水利工程0901班 water-saving irrigation1. existing water-saving irrigation methodsirrigation methods, field water distribution method is how to have been sent to the farms, the irrigation water is evenly distributed to the active layer of the crop root. irrigation water

2、 is the means by which to enter the active layer of roots, irrigation methods can be divided into surface irrigation, sprinkler irrigation, micro-irrigation and underground irrigation.1.1 surface irrigationsurface irrigation is an ancient traditional irrigation method, in general, it is as compare w

3、hether water-saving basis points. surface irrigation technology are constantly develop and constantly improve, so there are many more water-efficient than traditional surface irrigation technology.1.1.1 new furrow irrigation toolstraditional furrow irrigation with artificial opening from the distrib

4、ution channel water into the furrow, it is neither accurate and inconvenient, and often cause the field of water loss due to water port leakage countries have already adopted the siphon (for open channel water ) or gate hole pipe (aqueduct) drainage, china has done a number of tests, proven to impro

5、ve field water utilization rate of 5% to 10%.1.1.2 surge irrigationmodern foreign developed wave chung (groove) border irrigation or intermittent ditch (furrow) irrigation, traffic control into the ditch (furrow) is intermittent water and then put a period of time (a few minutes or tens of minutes)

6、to field stop the water for some time (a few minutes or tens of minutes), and so forth, so that you can make along the ditch (furrow) the length direction of the water distribution is more uniform. fields of water utilization up to 80% to 90%.film hole irrigation (also known as the film hole irrigat

7、ion)gully, made on the film of water flow in the membrane, crops grow hole to penetrate the land, so that irrigation efficiency is high, generally water-saving 25% to 35%, an increase of 15% to 20%, they do not specifically facilities.1.2 irrigationsprinkler to spray through the air, due to the pres

8、sure of the commonly used pressure aqueduct. in general, its obvious advantages irrigation uniformity, less of farmland, save manpower, strong adaptability to the terrain. the main disadvantage is influenced by wind, high investment in equipment. more in our country are the following: fixed pipe spr

9、inkler, the semi-mobile pipeline sprinkler irrigation, a rolling shift sprinkler manifold, when the needle irrigation machine, a large pan spray irrigation machine, grain irrigation machine in microirrigators units and so on.1.3 drip irrigationirrigation water with a small plastic tube directly sent

10、 to the the meike crop roots near the water drip out slowly by drippers, a sophisticated irrigation methods, only need water to irrigation can truly only irrigation crop instead of filling the land. and can be a long time in the crop root zone moisture in the optimal state, so to save water and incr

11、ease production. but its biggest drawback is the dripper out flow orifice is small, the flow rate is low, so serious congestion problems. irrigation water must be carefully filtering and processing. at present, china has only noticed to prevent physical clogging equally serious clogging the biologic

12、al and chemical clogging problem has not been taken seriously enough. the main way of drip irrigation: fixed-ground drip irrigation, semi-fixed-ground drip irrigation. membrane under irrigation, drip irrigation and other underground.1.4micro-sprinkler irrigationsome places called mist irrigation, an

13、d drip irrigation similar too easy just to overcome the dripper disadvantage of clogging the drippers to micro sprinklers, micro-sprinkler flow orifice large, large number of traffic flow rate faster unlike drippers so easy to plug, but the traffic has increased, capillary accordingly should bold so

14、me 1 to 2 micro sprinklers installed in every crop or tree usually can meet the needs of irrigation. micro nozzle still clogged filtration problems, and therefore should be given adequate attention, the cost per hectare is similar to fixed-drip irrigation. gradually replaced by drip irrigation micro

15、 sprinkler irrigation in a foreign country. especially suitable for irrigated orchards.1.5 subsurface irrigationsimilar to the subsurface irrigation and underground drip, just the dripper all buried in the underground seepage head instead, the seepage head of water unlike drippers as drop by drop ou

16、tflow, but slowly seepage, such seepage head is not easy soil particles and root blockage. recently introduced in a foreign country using waste tires processed into porous percolation pipe, and the pilot of a small area, but the clogging of the micropores seepage pipe is a serious problem, without t

17、he test to test for a long time should not be hastily promotion.1.6underground irrigationthe underground irrigation irrigation is a method to control the water table. to irrigation groundwater table elevation to the water can enter the height of the root activity layers, the ground remains dry, so v

18、ery provincial water, no irrigation, groundwater levels drop down. the limitations of this approach, only the root activity layers impermeable layer caixing.2. select the factors that affect water-saving irrigation methods2.1 weather conditionschina from the southeast coast to the inland northwest,

19、generally divided into sub-humid areas, semi-humid areas, semi-arid and arid regions, with dryness incremental, the dependence of crop irrigation is incremented accordingly. humid regions for many years the average annual rainfall is greater than the cultivation of dry crops in the field water consu

20、mption, water resources total more than just a lack of precipitation in the dry season and drought years, supplemental irrigation is required; semi-humid areas average annual rainfall is basically in line with planting drought crop water demand, but due to the uneven distribution of precipitation, d

21、ry years and dry season water shortages more; semi-arid areas average annual rainfall can not meet the crop water requirements, if there is no irrigation, agricultural production is very unstable, such areas such as irrigation, wasteland farming, the destruction of natural vegetation, can easily cau

22、se desertification; rainfall is scarce in arid regions, irrigation agriculture, water scarcity of such areas, river runoff from the alpine rain and snow melt water, industry and agriculture not only depend on the development and survival of the natural vegetation along the river channel near river w

23、ater for irrigation, and therefore reference, must take into account the natural ecological water. 2.2 the topography and hydrogeological conditionstopography and hydrogeological conditions affecting the natural distribution of rainwater, will also affect the pattern of water-saving irrigation. grou

24、nd on steep mountain hilly area prone to soil erosion and drought, water-saving irrigation to adopt comprehensive measures. cultivation technology and terracing, field ridges through agricultural consumption, reduce the sloping soil erosion and soil evaporation; gullies on the construction of embank

25、ments, or in suitable locations for the construction of water cellars, storing runoff solve drinking water and a small area irrigation water; repair reservoirs in the gullies and tributaries, centralized control runoff diversion project isolated tangba communication, formation of chodo jiegua-irriga

26、tion systems, improve rain water utilization and irrigation water to ensure rate.2.3 the use of surface water resources conditionsplain areas and open mountain basin, water conditions were better, but different parts have significant differences. piedmont sloping plain terrain slope, coarse sediment

27、, runoff smooth, rich groundwater recharge, water quality, is conducive to the development and utilization. slowing the central plains terrain slope sediments thinning increased level surface several times due to river flood diversion, post depression to staggered, affect runoff excretion increased

28、groundwater salinity under arid climatic conditions, soil there will be varying degrees of salinization phenomenon. the plains lower part of the lakeside and coastal area, low and flat, the soil is heavy clay, surface and underground runoff, poor drainage, arid climatic conditions, high salinity of

29、groundwater development and utilization of difficulties, serious soil salinization. this region in the river downstream, dry season, the rivers and the rainy season is threatened by the flood, so building large and medium-sized irrigation and well irrigation area in the plains area, due to the diffe

30、rent parts of which the landforms, water conditions and accompanying drought waterlogging, salinity and other disasters also vary from place to place.2.4 specific plantingfruit trees, irrigation quota vary according to the type of fruit trees, varieties and rootstock characteristics, age size. droug

31、ht-tolerant tree species, such as jujube, chestnut and rootstock species with lower water requirements the irrigation quota can be as small; poor drought tolerance of species, such as grapes, apples, pears, irrigation quota should be larger. the saplings should be less irrigation, the results of fru

32、it trees can be more than irrigation. saudi orchards should small water more than irrigation. saline land orchard irrigation should be noted that the groundwater level, in order to prevent the return of salt, returned to base. generally into one of the most suitable age fruit trees irrigation, soil

33、moisture completely wet fruit tree roots within appropriate. under the conditions of use of water-saving irrigation methods, irrigation to reach a depth of 0.4-0.5 meters, plenty of water up to 0.8-1.0 meters.to mature vine irrigation, mainly in the grape growing infancy, before and after flowering,

34、 berry enlargement period and grapes after harvest period, the general irrigation 5-7 times.節(jié)水灌溉一現(xiàn)有的節(jié)水灌溉方法灌水方法即田間配水方法，就是如何將已送到田頭的灌溉水均勻地分布到作物根系活動(dòng)層中去。按灌溉水是通過(guò)何種途徑進(jìn)入根系活動(dòng)層，灌水方法可分為地面灌溉、噴灌、微灌和地下灌溉。(一)地面灌溉地面灌溉是古老的傳統(tǒng)的灌水方法，一般說(shuō)來(lái)它是作為比較是否節(jié)水的基點(diǎn)。但是地面灌溉技術(shù)也在不斷發(fā)展不斷完善，所以最近也有許多比傳統(tǒng)地面灌溉技術(shù)更節(jié)水的方法。1.新的溝畦灌水工具傳統(tǒng)的溝畦灌水是用人工從配水渠開(kāi)

35、口放水入溝畦，這樣既不準(zhǔn)確又不方便，而且常因放水口滲漏造成水的田間損失，國(guó)外早已采用虹吸管(用于明渠輸水的情況)或閘門(mén)孔管(用于管道輸水的情況)放水，我國(guó)已做了一些試驗(yàn)，證明可提高田間水利用率5%10%。2.波涌灌溉近代國(guó)外又研究出波涌(溝)畦灌或稱間歇溝(畦)灌，就是控制放入溝(畦)的流量是間歇的，向田間放一段時(shí)間(幾分鐘或幾十分鐘)的水然后停止放水一段時(shí)間(幾分鐘或幾十分鐘)，如此反復(fù)，這樣可以使沿溝(畦)長(zhǎng)度方向的水量分布更加均勻。田間水利用率可達(dá)80%90%。3.膜上灌(又稱膜孔灌)在地膜上做成溝狀，水就在膜上流動(dòng)，到作物長(zhǎng)出孔處才滲入土地，這樣灌水效率高，一般可節(jié)水25%35%，增產(chǎn)

36、15%20%，又不要專門(mén)的設(shè)施。(二)噴灌噴灌是通過(guò)空中進(jìn)行噴水，由于需要壓力所以常用壓力管道輸水。一般說(shuō)來(lái)，其明顯的優(yōu)點(diǎn)是灌水均勻，少占耕地，節(jié)省人力，對(duì)地形的適應(yīng)性強(qiáng)。主要缺點(diǎn)是受風(fēng)影響大，設(shè)備投資高。在我國(guó)用得較多的有以下幾種：固定管道式噴灌、.半移動(dòng)式管道噴灌、滾移式噴灌支管、時(shí)針式噴灌機(jī)、大型平移噴灌機(jī)、紋盤(pán)式噴灌機(jī)以及中、小型噴灌機(jī)組等。(三)滴灌是用小塑料管將灌溉水直接送到每棵作物根部的附近，水由滴頭慢慢滴出，是一種精密的灌溉方法，只有需要水的地方才灌水，可真正做到只灌作物而不是灌土地。而且可長(zhǎng)時(shí)間使作物根區(qū)的水分處于最優(yōu)狀態(tài)，因此既省水又增產(chǎn)。但其最大缺點(diǎn)就是滴頭出流孔口小，流

37、速低，因此堵塞問(wèn)題嚴(yán)重。對(duì)灌溉水一定要認(rèn)真地進(jìn)行過(guò)濾和處理。目前我國(guó)還都只注意到防止物理堵塞，而同樣嚴(yán)重的生物堵塞和化學(xué)堵塞問(wèn)題尚未引起足夠的重視。滴灌的主要方式有：.固定式地面滴灌、半固定式地面滴灌、.膜下灌、地下滴灌等。(四)微噴灌有的地方稱之為霧灌，與滴灌相似，只是為了克服滴頭太易于堵塞的缺點(diǎn)，將滴頭改為微噴頭，由于微噴頭出流孔口大一些，流量大一些，流速快一些，所以不像滴頭那么容易堵塞，但流量加大了，毛管相應(yīng)也要加粗些，在每棵作物或樹(shù)下裝12個(gè)微噴頭一般即可滿足灌溉的需要。微噴頭仍有堵塞問(wèn)題，因此也要對(duì)過(guò)濾問(wèn)題給予足夠的重視，每公頃造價(jià)與固定式滴灌相仿。在國(guó)外有逐漸以微噴灌取代滴灌的趨勢(shì)。特別適用于灌溉果園。(五)滲灌滲灌與地下的滴灌相似，只是用滲頭代替滴頭全部埋在地下，滲頭的水不像滴頭那樣一滴一滴地流出，而是慢慢的滲流出來(lái)，這樣滲頭不容易被土粒和根系所堵塞。最近在國(guó)外引進(jìn)采用廢輪胎加工成的多孔滲流管，并進(jìn)行小面積試點(diǎn)，但是微孔滲流管的堵塞是一個(gè)嚴(yán)重的問(wèn)題，未經(jīng)長(zhǎng)時(shí)間試驗(yàn)檢驗(yàn)不宜貿(mào)然推廣。(六)地下灌溉地下灌溉是用控制地下水位的方法進(jìn)行灌溉。在要灌溉時(shí)把地下水位抬高到水可以進(jìn)入根系活動(dòng)層的高度，地面仍保持