摘要
焉耆盆地位于新疆巴音郭楞蒙古自治州境内,是南疆主要粮食基地,也是库尔勒的主要供水水源地。盆地中心为我国最大的内陆淡水湖——博斯腾湖(简称“博湖”)。20世纪50年代以来,由于大量引用地表水灌溉,致使灌区潜水位普遍上升,并造成该区土壤次生盐渍化、地下水和博斯腾湖水咸化和生态环境退化等一系列不良现象。
本研究以典型区为例,探讨地下水浅埋深条件下的土壤水盐动态变化特征,分析了土壤水分的变化规律以及影响土壤盐分的各个因素。在此基础上,构建出典型区土壤水盐运移二维数值模型,并运用此模型,对制定出来的多种灌溉制度进行对比,从土壤水分和盐分两方面综合进行考虑,得出适合该区的灌溉制度。本研究的主要结论有:
1.典型区地下水位变化受灌溉作用影响,灌溉前后变化较大,无灌溉期由于底部潜水补给,变化不明显。典型区深层地下水矿化度变化不大,年际变化在0.575～0.717g/L之间;浅部地下水的矿化度变化较大,最高7.38,最小为3.76g/L,但总体趋势是趋于淡化。
2.受灌溉影响,典型区耕地较周边荒地土壤含水量动态变化强烈,10cm深度处耕地土壤含水量变异系数高达0.59,而荒地仅0.05。灌水后,典型区土壤含水量发生重分布,20cm以上变化不大,但在20cm深度处含水量达到饱和含水量峰值,待灌溉数天后,逐渐减小,接近土壤残余含水量。在150cm深度以下含水量趋于稳定,变异系数在0.01—0.04之间。
3.典型区30cm深度以上多年土壤盐分的峰值都出现在5、6月份,7～9月份相对稳定。30cm深度以下,土壤盐分越靠近地下水位越趋于稳定。
4.运用信息统计方法讨论了土壤盐分与地下水位的关系,结果表明表层0～30cm的土壤盐分在潜水埋深处于0～100cm时影响最大;60～220cm的土壤水矿化度在潜水埋深处于100～130cm时影响最大。
5.运用多元统计技术,利用SPSS软件中的相关分析模块,分析了土壤组分对盐分的影响,结果表明:砂粒与土壤盐分的皮尔逊相关系数为-0.263,粉粒为0.38,粘粒为-0.507,双尾显著性检验分别为0.015,0.000,0.000都通过了显著性检验,说明典型区土壤盐分主要受粘粒含量影响。
6.运用回归分析方法,建立了土壤盐分Y与矿化度X的关系式:Y=0.1873X-0.1856,相关系数为0.837,显著性检验为0.001。
7.从微观角度出发,用相关分析法分析了土壤盐分与离子组分之间的关系,结果表明土壤盐分主要与Cl~-、SO_4~(2-)、(K~+Na~+)、Mg~(2+)这四类离子相关性较大,在深度上面有稍许变化。
8.建立了典型区土壤水盐运移二维数值模型,并采用2001年4月15日—12月30日,共计260天的水盐实测数据对模型进行了校准和验证,确立了可靠的典型区水盐运移数值模拟模型。
9.以小麦为例,分别考虑作物需水量和当地实际灌溉制度,改变灌溉量和间隔和次数,制定了三种灌溉方案,通过模型对不同灌溉方案下的土壤水盐运移特征进行模拟预测,通过土壤盐分的积聚变化特征,选取了适宜典型区的灌溉制度。
10.对适宜本区的灌溉方案进行了数值模拟计算,在灌溉量、作物需水量、土壤盐分上与前面的三种方案进行了对比,确定了这种方案的优越性。
本次研究为更好地揭示干旱内陆盆地田间地下水—土壤水盐运移规律提供了理论依据和研究平台,对区内的农业生产、生态环境以及经济发展都具有重要的现实意义。
本文主要特色为,从典型区水盐运移特征出发,建立了本区二维水盐运移数值模型,并利用模型,对灌溉制度进行了模拟计算,在考虑作物需水量、灌溉量和土壤盐分的情况下,分析得出了适宜本区灌溉方案,为本区农业生产和灌溉用水提供了理论依据。
This research takes typical experiment area as an example, discusses the dynamic variation characteristics of the soil salt and water on the condition of shallow water table, analyzes the variation law of the soil water and some influencing factors of the soil salt. On this basis, sets up the two-dimensional numerical model for the movement of soil water and salt in typical area, and makes use of this model, compare with the various irrigation programs, consider the soil water and the salt synthetically , gained the irrigation program adapt to this area. The main conclusions of are as follow:
1. The variety of the groundwater level in typical area is subjected to the irrigation function, relatively great fore-and-aft irrigation; It's not obviously change if have no irrigation, because the supply of phreatic water. The mineralized degree of deep groundwater is not changed too much in typical area, interannual variations is between 0.575-0.717g/L, the shallow groundwater is relatively great, the maximum is 7.38 g/ L, the minimum is 3.76 g/ L. But the total trend is desalt.
2. Under the influence of irrigation, the variety of soil water content in typical area farmland is bigger than in the peripheral wasteland. The variable coefficient of the soil water content at depth of 10cm in farmland soil is up to 0.59, but is only 0.05 in the wasteland. Moreover, after irrigation, the soil water content is distributed over again in typical area, the soil water above 20cm soil doesn't change greatly; but at depth of 20cm, the amount of soil water content become saturated, past a few days after irrigation, the soil water minimizes gradually, nearing to the remain soil water content. The soil water content is tends stabile at depth of 150cm, the variable coefficient is between 0.04 and 0.01.
3. The peak value for many year of the soil salt above depth of 30cm appears in June or July in typical area, stabile comparatively in September. Below 30cm depth, soil salt is more stabile near the groundwater level.
4. Making use of the information statistic method discusses the relation between the soil salt and the groundwater level, the result shows that: when the depth is 0-100cm, the surface soil salt between 0-30cm is influenced most with groundwater depth; The mineralized degree of soil water between 60-220cm depth is influenced biggest with the groundwater depth when the depth is placed at 100-130cm.
5. By the thought of multivariate statistics, making use of correlation analysis model in the SPSS software, analyzes the effect of soil salt by the soil compositions, the result indicates: the Pearson's correlation coefficient is -0.263 between the sand and the soil salt, the silt is 0.38, the clay is 0.507, 2-tailed significant examines is 0.015, 0.000, 0.000, all passed the significant examination.All these show that the soil salt is influenced by the clay mainly in typical area.
6. Making used of the regression analysis method, sets up the relational expression between soil salt Y and mineralized degree X: Y=0.1873X-0.1856, the related coefficient is 0.837, significant examines is 0.001.
7. From microcosms, using the method of correlation analysis, analyzes the relation between the soil salt and the ions, the result shows the relativity of soil salt is great with Cl~-、SO_4~(2-)、(K~++Na~+)、Mg~(2+) these four ions, on the depth is slight variety.
8. Sets up the two-dimensional numerical model for the soil water and salt movement in typical area, and adopts the measured data to contrast and verify the model, the date is between the 15~(th),April,2001 and 30~(th),December,add up to 260 days, the result shows that the model is creditable.
9. Take wheat as an example, considers crop's water requirement, the practical irrigation program and irrigation program in model, changes irrigation quantity, partition and of times, draws up three kinds of irrigation program, compares the water and salt by this model, gets the irrigation program adopt the typical area, is the irrigation program comprehensive consider the crop water requirement and winter irrigation for wash soil salt.
10. The irrigation scheme that suitable for the region was calculated, contrast with the other three schemes on irrigation amount、crop water requirement and soil salt ,knows the superiority of this scheme.
This research provides theory basis and flat roof for better reveal the order of groundwater-soil water and salt movement. It is significance for agriculture yield, environments improvement and economy development in Yanqi Basin.
The features of my paper are: from the water and salt transport features, sets up the two-dimensional numerical model for the soil water and salt movement in this area, and by this model, calculates the irrigation scheme ,considering irrigation amount、crop water requirement and soil salt, gets the irrigation program that suitable for the region. Therefore it provides the theoretical basis for the development of agricultural production and irrigation water in this area.
引文
[1] Allen R G, Pereira L S, Raes D, et al. Crop evapotranspiration guidelines fo r computing crop water requirements [M ]. Rome: FAO Irrigation and Drainage Paper No. 56. 1998.
[2] Allen R, Smith G, Perrier M, et al. An update fo the definition of reference evapotransp iration [J]. ICID Bulletin. 1994,43(2): 1-34.
[3] Bahceci.et al. Water and salt balance studies, using SaltMod, to improve subsurface drainage design in the Konya-Cumra Plain, Turkey. Agric. Water Manage. 2006,85:261-271.
[4] Ben.J-A sher, Ch Charach. Infiltration and water extraction from trickle irrigation source, The effective hemisphere model[J]. Soil Sci Soc Am J, 1986, 50: 882-887.
[5] Brandt A, Bresler E, Ben-A sher, et al. Infiltration from a trickle Source: E. M athematical Models. Soil Sci. Soc. Amer. P roc. 1971,35:675-682.
[6] Bresler E.Simultaneous transport of solutes and water under transient unsaturated flow condition. Water Resources. 1973,9:975-986.
[7] Carse,R.F, Parrish,R.S..Developing joint probability distributions of soil water retention characteristics, Water Resourse Resaearch. 1998,24:755-769.
[8] Causape'J,Qui'lez.D,Aragues.R..Groundwater quality in CR-V irrigation district (Bardenas Spain): Alternative scenarios to reduce off-site salt and nitrate contamination. Agricultural Water Management 84(2006)281-289.
[9] Childs S.A simplified model of corn growth under moisture stress. Trans of the ASAE. 1977,22:858-865.
[10] Clothier B E, Kirkham M B, Mclean J E, In situ measurements or the effective transport volume for solute moving through soil. Soil Sci. Soc. Am. J.1992,56;733-736.
[11] Clothier.Diffusivity and one-dimensional absorption experiment.Soil Sci. Soc.Am.Proc.1983, 47:641-644.
[12] Dane J H, Mathis F H. An adaptive finite difference scheme for the one dimensional water flow equation [J].Soil Science Socioty of American Journal, 1981,45:1048.
[13] Ellen Milnes, Pierre Perrochet. Direct simulation of solute recycling in irrigated areas. Advances in Water Resources 2006,29:1140-1154.
[14] Feddes R.A.,P.J.Kowalik and H.Zarady.Simulation of field water use and crop yield.Simulation Monographs,PUDOC,Wageningen. 1978:21-30.
[15] Gardner W R.Dynamic aspects of water availability to plants. Soil Sci,1960,89:63-73.
[16] Hanks R J, Bowers S B. Numerical solutions of the diffusion equation for the movement of water in soils[J].Soil Science Socioty of American Journal,1962,26:530.
[17]Houk E.The agricultural impacts of irrigation induced waterlogging and soil salinity in the Arkansas Basin.Agricultural Water Management 2006(85):175-183.
[18]Hwang,JC.Finite analytic numerical solution for two2dimensional groundwater solute transport[J].Water Resource,1985,21(9):1354.
[19]Jorenush M.H,Sepaskhah A.R.Modeling capillary rise and soil salinity for shallow saline water table under irrigated and non-irrigated conditions.Agricultural Water Management 61(2003)125-141.
[20]Karlberg,L.et al.,Low-cost drip irdgation-A suitable technology for southern Africa?,Agric.Water Manage.(2007),doi:10.1016/j.agwat.2006.12.011.
[21]Karlberg.L,F.W.T.Penning de Vales.Exploring potentials and constraints of low-cost drip irrigation with saline water in sub-Saharan Africa.Physics and Chemistry of the Earth 29(2004)1035-1042.
[22]Konukeu.F,Gowing.J.W,Rose.D.A.Dry.drainage:A sustainable solution to waterlogging and salinity problems in irrigation areas.Agricultural water management 2006,83:1-12.
[23]Mermoud A.et al.Impacts of different irrigation schedules on the water balance components of an onion crop in a semi-add zone.Agricultural Water Management.2005(77):282-295.
[24]Northey J.E..Occurrence and measurement of salinity stratification in shallow groundwater in the Murrumbidgee Irrigation Area,south-eastern Australia.Agricultural Water Management 81(2006)23-40.
[25]Ruan F,McLaughlin D.An investigation of Eulerian Lagrangian methods for solving heterogeneous advection dominated transport problems[J].Water Resource,1999,35(8):2359.
[26]Sarangi.et al.,Subsurface drainage performance study using SALTMOD and ANN models.Agricultural water management.84(2006)240-248.
[27]Sharma M L.Extimating evapotranspiration.Advnces in Irrigation,1983.
[28]Simunek J.,Vogel T.and van Genuchten M.Th..The SWMS-2D Code for Simulation Water Flow and Solute Transport in Two-Dimensional Variably Saturted Media(Version 1.2).U.S.Salinity Laboratory,USDA.ARS.1994.
[29]Singh.et al.Distributed ecohydrological modeling to evaluate the performance of irrigation system in Sirsa district,India:Ⅰ.Current water management and its productivity.Journal of Hydrology(2006)329,692-713.
[30]Skaggs.et al.Macroscopic approaches to root water uptake as a function of water and salinity stress,Agric.Water Manage.86(2006)140-149.
[31]Tsakiris Gand Kiountouzis E.A model for the optimal operation of an irrigation system.Agric.Water Manage.1982,5:241-252.
[32]Van Genuchten,M.Th.(1998).A closed-form equation for predicting the hydraulic conductivity soils.Soil Sciences Society of America Journal,44:892-898.
[33]Vogel T.Modeling flow and transport in a two-dimensional dual-permeability system with spatially variable hydraulic properties.Journal of Hydrology 238(2000)78-89.
[34]Wagenet.R.J,Bhaskar K.Rao.Descdption of nitrogen movement in the presence of spatially variable soil hydraulic properties.Agricultural Water Management.Volume 6,Issues 2-3,May 1983,Pages 227-242.
[35]陈大春.新疆焉耆盆地地表水地下水联合调度应用研究[D].乌鲁木齐:新疆农业大学,2000.
[36]陈模,杨绍斌.焉耆盆地盐渍化土壤的形成与改良[J].国土与自然资源研究,1992,(3):46-49.
[37]陈启生,戚隆溪.有植被覆盖条件下土壤水盐运动规律研究[J].水利学报,1996,(1):1.
[38]陈兴武,赵奇,宋敏,等.灌溉制度对春小麦田间水分状况及其生长的影响[J].新疆农业大学学报,2001,24(3):28-31.
[39]陈玉民,肖俊夫,王宪杰,等.非充分灌溉研究进展及展望[J].灌溉排水,2001,20(2):73-75.
[40]程维新.农田蒸发与作物耗水量研究[M].北京:气象出版社,1994.
[41]崔远来,袁宏源,李远华.考虑随机降雨时稻田高效节水灌溉制度[J].水利学报,1999,7:40-45.
[42]杜金龙,靳孟贵,欧阳正平,等.焉耆盆地土壤盐分剖面特征及其与土壤颗粒组成的关系[J].地球科学,2008,33(1):131-136.
[43]郭良,石国元,张正华,等.地埋滴灌棉田土壤水盐运移特性[J].中国棉花,2004,31(12):10-12.
[44]黄运祥.新疆焉耆盆地盐碱土综合治理与博斯腾湖生态保护优化模型[A].国际盐渍土改良学术讨论会论文集,1985.
[45]季方.塔里木盆地绿洲土壤水盐动态变化与调控[M].北京:海洋出版社,2001.99.
[46]姜卉芳,董新光,郭西万,等.新疆焉耆盆地水盐平衡模型的率定与检验[J].灌溉排水,2002,19(1):78.
[47]姜学健,杨继芝.不同灌溉制度旱作物田间盐分动态试验初报[J].塔里木农垦大学学报,2003,15(2):20.
[48]靳孟贵,刘延锋,董新光.节水灌溉与农业面源污染控制研究—以新疆焉耆盆地为例[J].地质科技情报,2002,21(1):51-54.
[49]康金虎,马文敏.宁夏引黄灌区微咸水灌溉利用试验研究[J].农业工程学报,2005,26(2):93-95.
[50]康绍忠,刘晓明,熊运章等.土壤-植物-大气连续体水水分传输理论及其应用[M].北京:水利水电出版社.1994.
[51]康绍忠.土壤-植物-大气连续体水分传输理论及其应用[M].北京:水利电力出版社.1994.
[52]雷志栋,杨诗秀,谢森传.土壤水动力学[M].北京:清华人学出版社.1988.
[53]雷志栋,杨诗秀.非饱和土壤水一维流动的数值计算[J].土壤学报,1982,19(2):141.
[54]李光永,郑耀泉,曾德超,等.地埋点源非饱和土壤水运动的数值模拟[J].水利学报,1996,(11):47-51.
[55]李旭华,王心义.包气带中污染物迁移转化规律研究[J].西部探矿工程,2006,(2):239-241.
[56]李韵珠,胡克林.蒸发条件下粘土层对土壤水和溶质运移影响的模拟[J].土壤学报,2004,41(4):493-501.
[57]李韵珠,李保国.土壤溶质运移[M].北京:科学出版社,1998.
[58]刘昌明.土壤-植物-大气连续体中蒸散发的计算[J].水科学研究与进展.1992,3(9);255-263.
[59]刘新永,田长彦,马英杰,等.南疆膜下滴灌棉花耗水规律以及灌溉制度研究[J].干旱地区农业研究,2006,24(1):108-112.
[60]刘延锋,靳孟贵,金英春.焉看盆地土壤盐渍化状况的主成分分析[J].干旱地区农业研究,2004,22(1):165-166.
[61]吕殿青,王文焰,王全九.滴灌条件下土壤水盐运移特性的研究[J].灌溉排水,2000,19(1):16-21.
[62]孟江丽,董新光,周金龙,等.HYDRUS模型在干旱区灌溉与土壤盐化关系研究中的应用[J].新疆农业大学学报,2004,27(1):45-49.
[63]孟江丽.水盐和排水系统的模拟研究[D].新疆:新疆农业大学,2004.
[64]戚隆溪,陈启生,逢春浩.土壤盐渍化的监测和预报研究[J].土壤学报,1997,34(2):189-199.
[65]尚松浩,毛晓敏,宣小忠,等.叶尔羌河绿洲潜在腾发量的变化特性[J].灌溉排水.1999.18(2):14-16.
[66]尚松浩.作物非充分灌溉制度的模拟-优化方法[J].清华大学学报(自然科学版),2005,45(9):1179-1183.
[67]史海滨,陈亚新.饱和-非饱和流溶质传输的数学模型与数值方法评价[J].水利学报,1993(8):49-55.
[68]史海滨,田军仓,刘庆华.灌溉排水工程学[M].北京:中国水力水电出版社,2006.47-55.
[69]司建华,冯起,李建林,等.荒漠河岸林胡杨吸水根系空间分布特征[J].生态学杂志.2007,26(1):1-4.
[70]宋运良,丁乃圩,许广森.污灌污染系统整体数学模型[J].水利水电技术,1996,(7):37-41.
[71]随红建,饶纪龙.土壤溶质运移的数学模拟研究-现状及展望[J].土壤学进展,1992.5.
[72]汤广民,王友贞.安徽淮北平原主要农作物的优化灌溉制度与经济灌溉定额[J].灌溉排水学报,2006,25(2):24-29.
[73]王全九.土壤溶质迁移特性的研究[J].水土保持学报,1993.2.
[74]王润兰,康卫东,杨小荟.焉耆盆地平原区水资源及其开发模式[J].西安工程学院学报,2001,23(2):12.
[75]王水献,周金龙,董新光.地下水浅埋区土壤水盐试验分析[J]新疆农业大学学报,2004,27(3):52-56.
[76]王水献.焉耆盆地典型试验区土壤水盐数值模拟研究[D].新疆农业大学.2005:46-47.
[77]王永康.干旱区高粱节水灌溉制度研究[J].节水灌溉,2004,(1):14-15.
[78]王政友,陈建峰.利用零通量面方法计算土壤水均衡要素的探讨[J].地下水,2002,24(3):141-142..
[79]杨培岭,郝仲勇.植物根系吸水模型的发展动态[J]中国农业大学学报.1994,4(2):67-73.
[80]叶海燕,王全九,刘小京.冬小麦微咸水灌溉制度的研究[J].农业工程学报2005,21(9):27-32.
[81]叶自桐.利用盐分迁移函数模型研究入渗条件下土层的水盐动态[J].水利学报,1990,(2):45-49.
[82]仪垂详.非线性科学在地学中的应用[M].北京:气象出版社,1995.53-59.
[83]袁宏源,刘肇伟.高产省水灌溉制度优化模型研究[J].水利学报,1990,(11):45-55.
[84]张德生,沈冰.土壤中反应溶质运移的对流-弥散模型及其解析解[J].西安理工大学学报,2001,17(2):122-126.
[85]张妙仙,杨劲松.地下水埋深对土壤及地下水盐分影响的信息统计分析[J].土壤,2001,(5):239-242.
[86]张蔚榛.包气带水文动力学[M].武汉:武汉水利水电出版社.1994.
[87]张蔚臻.土壤水盐运移数值模拟的初步研究[C].农田排灌及地下水土壤水盐运动理论和应用论文集,1992:244-263.
[88]赵云翔.渭北早塬花椒非充分灌溉制度试验研究[J].人民黄河,2006,28(10):53-54.
[89]郑西来,钱会,杨喜成.地下水含水介质的弥散度测定[J].西安工程学院学报,1998,20(4):30-36.
[90]周金龙,董新光,艾克木阿不都拉.天山北坡平原区零通量面形成发育规律研究[J].新疆农业大学学报,2003,26(1):62-65.
[91]周金龙,董新光,陈文娟,王智.应用彭曼-蒙特斯公式计算天山北坡平原区水面蒸发量[J].新疆农业大学学报,2002,25(4):35-35.
[92]周钟瑜.土壤水分测定方法[M].北京:水利电力出版社.1986.64-86.