不受潮汐影响城镇圩区排涝泵站群常规调度方案优化

为降低不受潮汐影响城镇圩区排涝泵站群常规调度能耗,提出了排涝总能耗最小单目标选优和圩区内(外)河水位限制多目标去劣的优化方法。为圩区排涝泵站群常规调度确定若干种典型排水条件组合,对每组排水条件,以泵站为试验因素、各泵站不同的运行规则为试验水平、不同运行规则组合下的最小运行能耗为试验结果开展正交试验;对试验结果开展正交分析获得各泵站从优到劣不同运行规则组合序列。对每组运行规则序列,根据各泵站排水能力限制,应用动态规划法可获得圩区泵站群最低排涝能耗及对应的各泵站开机方案;对最低排涝能耗排序可获得圩区泵站群优化运行方案序列,进一步应用圩区内(外)河水位限制条件可获得圩区泵站群某排水条件下最优调度方案。以上海市城区某区域为实例,阐明了优化计算全过程,优化计算结果比现行调度方案的排涝能耗至少可节省6%。     

Review of water table depth planning for a multi objective water management system

In this paper, the concepts for planning and design of drainage depth will be reviewed in relation to the different requirements for maximizing crop production. The relationships of the drainage depth with other design parameters and their interdependency will be discussed. Reference will be made to the cost, cost/benefit ratio and economic returns of drainage systems with respect to the drainage depth. Some applications and practices in different countries will be highlighted.     

暗管控制排水对棉田排水的影响

对几次较大规模降雨产生排水后排水量、排水氮素含量、地下水位等进行观测,结果发现暗管排水使得地表、地下排水量被重新分配,控制水位排水使地表排水量所占比例提高、而总排水量比常规排水减少36.4%～82.7%、地下排水峰值量较常规排水减少7.2%～85.4%。地表、地下排水硝氮质量浓度较低,一般低于4 mg/L;地表排水总氮质量浓度在2.3～11.5 mg/L之间,地下排水总氮质量浓度在0.6～9.1 mg/L之间。要减少氮素流失总量,减少排水量是关键。     

关于新疆叶尔羌河灌区排水问题的认识

以叶尔羌河灌区为对象, 讨论了内陆干旱区绿洲灌区排水的条件和特点。对内陆干旱区排水的重要特点即旱排与生物排水作出估计, 提出努力实现“水盐平衡”是排水的目标, 在进行排水规划同时也应作出排盐规划     

Predicting effects of drainage water management in Iowa's subsurface drained landscapes

Long-term hydrologic simulations are presented predicting the effects of drainage water management on subsurface drainage, surface runoff and crop production in Iowa's subsurface drained landscapes. The deterministic hydrologic model, DRAINMOD was used to simulate Webster (fine-loamy, mixed, superactive, mesic) soil in a Continuous Corn rotation (WEBS_CC) with different drain depths from 0.75 to 1.20 m and drain spacing from 10 to 50 m in a combination of free and controlled drainage over a weather record of 60 (1945-2004) years. Shallow drainage is defined as drains installed at a drain depth of 0.75 m, and controlled drainage with a drain depth of 1.20 m restricts flow at the drain outlet to maintain a water table at 0.60 m below surface level during the winter (November-March) and summer (June-August) months. These drainage design and management modifications were evaluated against conventional drainage system installed at a drain depth of 1.20 m with free drainage at the drain outlet. The simulation results indicate the potential of a tradeoff between subsurface drainage and surface runoff as a pathway to remove excess water from the system. While a reduction of subsurface drainage may occur through the use of shallow and controlled drainage, these practices may increase surface runoff in Iowa's subsurface drained landscapes. The simulations also indicate that shallow and controlled drainage might increase the excess water stress on crop production, and thereby result in slightly lower relative yields. Field experiments are needed to examine the pathways of water movement, total water balance, and crop production under shallow and controlled drainage in Iowa's subsurface drained landscapes.     

沿江圩区局部洼地排涝模数关联因子分析及应用

沿江圩区局部洼地涝灾频发,是目前圩区涝灾治理的重点.针对局部洼地排涝特点,以扬州江都沿江开发区为例,通过排涝水文分析计算得到排涝模数与排涝面积、水面率、调蓄水深、暴雨重现期4种关联因子之间的关系,选取典型区对局部洼地涝灾进行成因分析,并在此基础上提出圩区内局部洼地涝灾的防治措施.结果表明:排涝面积与排涝模数的偏相关系数为-0.905,相关性最大;局部洼地排涝面积小,洪水汇流速度快,洪峰径流模数和排涝模数较大;局部洼地区缺乏小型河网、河流间距过大、水系布置不合理和采用排涝模数较低,是涝灾频发的主要原因.以关联因子分析和成因分析为基础,提出了通过缩小河流间距、增加水面率、充分发挥河道的调蓄作用等措施以防治涝灾的产生,并且提出了符合圩区局部洼地水情特征的一种排水管网与河道布置模式.     

农田排水策略对氮素流失影响试验研究

通过测筒试验模拟了排水间隔时间、强度和地下水位对农田地下排水中氮素流失的影响规律。结果表明,相同模拟条件下,排水间隔时间的延长可减少排水量和降低总氮流失率,以间隔3～5d减少最为明显;间隔3、5和7d排水总氮流失量分别较间隔1d减少了45.5%、81.1%和100%;排水强度的降低可以减少氮素的流失,出流中氨氮质量浓度递减并趋于稳定,硝态氮质量浓度先上升后减少,相对于2mm/d的排水强度,4、6和8mm/d排水强度下总氮流失量分别增加了126.8%、264.8%和401%。地下水位的升高可明显减少总排水量和总氮流失量,40cm和60cm地下控制水位比80cm水位排水总氮量分别减少63.2%和40.9%。     

城市排涝与排水研究

城市排涝与排水是城市建设发展的一项重要工作。从比较城市排涝与排水异同点着手，分析研究二者之间的关系，对涝水重现期衔接、涝水流量计算方法、山坡汇水和小区而水与内河涝水叠加、小区雨水和内河涝水与外江水位组合以及城市规划地面标高确定等技术问题进行探讨，并对搞好城市排涝与排水工作提出一些看法。     

Drainage Design in the Gharb Plain in Morocco

The Gharb plain in Morocco faces both problems of excesswinter rainfall and salinity hazards due to a shallow,permanent and saline groundwater. A large area of 80.000 hahas been equipped with subsurface drains out of a totalplanned area of 200.000 ha. This system has been designedwithout any local references and has encountered severalmaintenance problems mainly caused by high drain depths.A pilot experiment has been installed to provide drainagedesign criteria appropriate to the local conditions. Mainexperimental results based on water and salinity balance andon groundwater flow are presented in the paper. They show thatin the Gharb plain, drainage systems should be designed fromwinter drainage design criterion. The paper also stresses onthe particular attention to paid to the surface drainage whichremove about 40% of the excess water.     

稻田灌溉排水自动控制新技术的研究

介绍一种适合于淹灌稻田实现自动控制的灌溉新技术，其中灌溉部分由自动给水栓、有压输水管道系统和灌溉水源三部分组成，自动给水栓有一个能自动跟踪稻田水层变化的传感装置，它与给水相连，当稻田水层消耗至允许下限时，传感器驱动给水栓开启放水；当稻田水层灌至设计上限时，关闭给水栓，停止灌水。管理人员只须根据作物不同生育阶段的灌水控制要求调定传感装置的上下限，稻田的灌溉既能自动完成。     

四湖流域农田排水有关问题研究

通过对四湖流域深入调查 ,提出应根据排水区业已形成的格局和降水分布差异分区选择排水设计雨量 ;联系项目实际论述了涝渍地集水小区明排系统规划中涉及的排水泵站经济性、排水沟道优化布局、排水工程建设的适度规模等问题 ;最后就涝渍地暗管排水工程及其推广问题进行了剖析     

新疆节水灌区农田排水措施分析

随着膜下滴灌技术在新疆的大力推广应用,灌排模式发生了改变,从而导致了新的土壤次生盐渍化问题。在阐述新疆3种排水措施——明沟排水、暗管排水和竖井排灌发展的基础上,分析了目前新疆节水灌区农田排水措施存在的问题,结合南疆某一节水灌区灌排试验,分析了排水措施对土壤盐分及地下水位、矿化度的影响,为当地灌排模式提出合理化建议,且为减轻节水灌区的土壤盐渍化提供参考借鉴。     

改进暗管排水结构型式对排水性能的影响

提出一种占用耕地少、排水流量较常规暗排大且环境友好的改进暗排。基于室内土柱试验,分析改进暗排在地表积水、土体饱和条件下的排水除涝性能及其机理,提出地表积水土体饱和入渗条件下改进暗排排水流量的理论计算公式。结果表明,改进暗排可以有效提高暗管排水能力,试验条件下,反滤体宽度为2~6 cm的改进暗排在自由出流条件下的排水流量为常规暗排排水流量的2~3倍;积水层深度相同时,改进暗排排水性能随反滤体宽度的增加而增大,但增幅逐渐减小;土体介质和反滤体的渗透系数差别越大,改进暗排的排水作用越明显。理论方法计算结果与试验结果相吻合,证明提出的理论计算公式是合理可行的。     

Analytical Approximation of Subsurface Total Drainage Quantity in Non-Steady State Drainage Flow, and its Verification in Heavy Soils

The subsurface total drainagequantity is one of the most importantindicators for the drainage policy of watermanagement. The methods of estimationof the subsurface total drainage quantityunder unsteady state drainage flow maybe different in consideration of the timeduration of the process and in relation tothe type, quality and quantity of the data used.Simple analytical approximation of thesubsurface total drainage quantity, whichwas developed by the operation of asubsurface pipe drainage system insaturated soil under unsteady statedrainage flow, is viewed in this paper.Derivation of the formula for subsurfacetotal drainage quantity is based onthe subsurface flow to drains with anapproximately horizontal impervious layer,where the Dupuit's assumptions and Darcy'slaw are applied. It is assumed that duringthe drainage process there will be no rechargeto the groundwater table.This analytical approximation of thesubsurface total drainage quantity at acertain time t was formed into a singleexponential equation. The correctness andapplicability of the analyticalapproximation of the subsurface totaldrainage quantity was verified with the help ofthe field measurements on the heavy soilsof an experimental watershed area of theResearch Institute for Soil and WaterConservation (RISWC) Prague-Zbraslav, CzechRepublic. The shape and the parameters ofthis subsurface total drainage quantityequation were also proved by nonlinearregression analysis, with application of themethod of Marquardt.This analytical approximation should serveas an elementary tool of water engineeringpractice for an immediate estimation of thevalues of subsurface total drainagequantities from field pipe drainagesystems in saturated soils. It shouldalso serve as a tool with only a minimumamount of information (the basic soilhydrology data and drainage system basicdesign parameters) and its application to awide range of drainage policies ispossible.     

Drainage design practices in France

Subsurface drainage annual rate boomed in France in late 70s and reached a steady rate of 130 000 hectares in 1982. As a consequence, better knowledge of drainage requirements, techniques and effects on farm management is requested. Emphasis has been put on preliminary survey planning. First of all extension and location of areas to be drained is determined with the help of farmers and local representatives within so-called “local juries”. Secondly, drainage recommandations are derived using the so-called “soil reference area” method. Drainage criteria and design methods are discussed on the basis of recent field experimental results. Drain spacing computation is related to tail recession stage; soil hydraulic properties are measured in situ using Guyon's pumping test. Subsurface and arterial drainage design rate are related to discharge exceedance duration curves and annual level of protection.     

农田暗管排水技术及其施工机械

基于暗管排水技术的国内外研究进展,介绍农田暗管排水技术的工作原理、应用情况,论述其在排盐方面的作用及效果,探讨暗管技术的布设、施工、维护机械设计研究现状,为提高暗管排水技术的推广应用提供理论参考.     

农田水利配套建筑物集合化研究

农田水利配套建筑物面广量大，为节省工程造价，充分发挥工程效益，加快配套步伐，作者根据配套要求以及建筑物的功能提出了集合化课题，并结合本地区实际进行了研究，将多物集合，达到一物多用，这对于促进农田水利建设水平的提高具有重要的意义。     

Drainage models to predict soil water regimes in drained soils: a UK perspective

Drainage is an intervention in the natural hydrology of the soil to alter the duration of adverse (waterlogged) soil conditions. The effects of drainage can be investigated by models that predict the position of the water table at a site in the presence of drainage. An inter-related series of models, which include the van Schilfgaarde non-steady state model, that have been used in the UK for the evaluation of drainage design options, are described. A simplified form of the van Schilfgaarde equation is presented, equivalent to a standard time series model, allowing both the efficient implementation of the model, and the inverse use of the model to derive performance parameters from observational data using statistical methods. A sensitivity analysis is used to investigate the relative importance of the two soil parameters, drainable porosity and soil hydraulic conductivity, on the performance of the model. This shows a far greater effect due to the variation of hydraulic conductivity.The use of a similar model to predict water tables in non-homogeneous soils has also been explored, including the investigation of a two-phase model to describe water movement in soils which are dominated by macropores. More useful, however, is the prediction of water table fluctuations in soils in which the soil hydraulic conductivity is a continuous function of soil depth, using the drainage theory of Youngs (1965). Solutions are presented for the logarithm of the hydraulic conductivity varying linearly with depth. The improvement in model performance is however gained at the expense of an additional parameter that describes the variation of hydraulic conductivity with depth. Some methods for deriving this parameter are discussed. Results from the use of this model are compared with those derived from the simple uniform conductivity model, showing superior performance.Lastly, the issue of soil lateral heterogeneity and the replicability of measurements is discussed. A detailed study of the variation of water table levels from a replicated drainage experiment indicates that in a practical situation very real limits exist on the accurate measurement of water tables, and that these present limits on our ability to verify models.     

农田排水资源灌溉利用适宜性评价指标体系研究

在广泛咨询和调研的基础上,首先确定了影响农田排水资源灌溉利用适宜性的各类重要因素,包括排水水质、作物特性、土壤特性、水文气象、灌排措施等5个方面,然后根据系统性、代表性、可操作性等原则,筛选了各个准则层下面指标层的具体指标,最后构建了比较完整的农田排水资源灌溉利用适宜性评价指标体系,为进一步开展农田排水资源灌溉利用适宜性评价提供了基础。     

Simulated effect of drainage water management operational strategy on hydrology and crop yield for Drummer soil in the Midwestern United States

The hypothetical effects of drainage water management operational strategy on hydrology and crop yield at the Purdue University Water Quality Field Station (WQFS) were simulated using DRAINMOD, a field-scale hydrologic model. The WQFS has forty-eight cropping system treatment plots with 10 m drain spacing. Drain flow observations from a subset of the treatment plots with continuous corn (Zea mays L.) were used to calibrate the model, which was then used to develop an operational strategy for drainage water management. The chosen dates of raising and lowering the outlet during the crop period were 10 and 85 days after planting, respectively, with a control height of 50 cm above the drain (40 cm from the surface). The potential effects of this operational strategy on hydrology and corn yield were simulated over a period of 15 years from 1991 to 2005. On average, the predicted annual drain flows were reduced by 60% (statistically significant at 95% level). This is the most significant benefit of drainage water management since it may reduce the nitrate load to the receiving streams. About 68% of the reduced drain flow contributed to an increase in seepage. Drainage water management increased the average surface runoff by about 85% and slightly decreased the relative yield of corn crop by 0.5% (both are not statistically significant at 95% level). On average, the relative yield due to wet stress (RYw) decreased by 1.3% while relative yield due to dry stress (RYd) increased by 1%. Overall, the relative crop yield increased in 5 years (within a range of 0.8-6.9%), decreased in 8 years (within a range of 0.2-5.5%), and was not affected in the remaining 2 years. With simulated drainage water management, the water table rose above the conventional drainage level during both the winter and the crop periods in all years (except 2002 crop season). The annual maximum winter period rise ranged between 47 cm (1995) and 87 cm (1992), and the annual maximum crop period rise ranged between no effect (2002) and 47 cm (1993).