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新疆叶尔羌河平原绿洲洼地旱排作用的初步分析 总被引:10,自引:2,他引:10
通过对新疆叶尔羌河流域平原绿洲一个典型洼地水量平衡的观测和计算,分析了洼地在容泄绿洲排水、排盐方面的旱排作用及排水、排盐能力。提出在绿洲排水规划时,可将旱排(或内排水)作为一种重要的排水方式,选择合适的洼地作为主要的旱排规划区。 相似文献
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叶尔羌平原绿洲盐均衡及旱排的初步分析 总被引:7,自引:0,他引:7
利用监测资料对叶尔羌平原绿洲监测区及分区的盐均衡和排出盐分的组成进行了分析。通过平原绿洲内部分水分迁移,不同土地利用型土地盐分特点和典型洼地蒸发耗水的分析,论述了绿洲的内排水及旱排作用。 相似文献
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关于新疆叶尔羌河灌区排水问题的认识 总被引:1,自引:0,他引:1
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。 相似文献
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为了探寻符合平原河网地区特点的排水系统最佳布置及管理方案,根据江苏常熟稻田排水观测试验,结合田间水文模型-DRAINMOD模型,分析了河网地区独特的水量平衡关系,确定了稻田排水量以及农田与外河的交换水量,并根据研究区的排水要求计算了可以削减的排水量。结果表明,在现有灌排制度下,生长期内稻田实际排水量约816mm,远高于当地所推荐的适宜排水量,可削减排水量约216mm,占目前灌水量的21.4%;按照当地所推荐的适宜排水量,利用DRAINMOD模型,当暗管埋深为90cm时,排水间距以25m为宜。研究区农田与外河的水位差较小,当外河距离农田大于30m时,实际水量交换很小;外河对农田的影响主要表现为对农田排水系统功能的抑制作用。 相似文献
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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。 相似文献
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Jakub Stibinger 《Irrigation and Drainage Systems》2003,17(4):341-365
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. 相似文献
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S. Bouarfa A. Hammani A. Debbarh D. Zimmer A. Taky C. Chaumont B. Vincent M. Zeraouli 《Irrigation and Drainage Systems》2002,16(2):89-110
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. 相似文献