共查询到19条相似文献,搜索用时 218 毫秒
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与传统耕作种植相比,微集水种植技术能够让水分更好的向土壤内渗透,改变土壤水分分布,提高土壤水分含量。不同的微集水种植技术的蓄水保墒效果不同,垄上覆膜沟内覆盖秸秆处理的蓄水保墒效果最好,该处理的集水构造不但能使降水更好的向土层深处渗透,而且秸秆覆盖处理还能减少土壤表层水分的无效蒸散,提高土壤蓄水量。 相似文献
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通过FLUENT软件的模拟计算,研究了不同微集水种植模式,降水在土层中下渗情况.分析结果表明:微集水种植模式能够加快降水在土层中的下渗速度,其中,垄上覆膜沟内覆膜处理水分下渗速度最快,说明垄上覆膜沟内覆膜处理更有利于降水储存到土层深处. 相似文献
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集雨滴灌技术在砂地西瓜种植中的应用 总被引:2,自引:0,他引:2
砂田是部分干旱半干旱地区传统保水保墒的耕作方式,至今已有300多年的历史。传统的砂田配合现代集水农业和先进的移动式滴灌技术种植西瓜,具有操作简便、投资小及产量成倍增加等特点,在干旱半年旱耕作传统 砂田地区有较好的实用价值。以甘肃景泰十里砂河村砂田种植西瓜为例,分析了雨水集蓄与砂田移动式滴灌节水技术之间的关系,同时还分析 研究了砂田的水分、养分、温度和产量之间的关系。 相似文献
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豫西大多数耕地分布在地形复杂水源缺乏地区。从这一事实出发,豫西需要发展喷滴灌,然而这里人口众多,经济落后,又无法照搬国外省外先进的喷滴灌技术。汝阳县十八盘乡微集水工程是适合当地条件的新型灌溉措施。 十八盘微集水灌溉分两种形式:一种暗蓄水的称水窑微集水;另一种明蓄水的称水窖 相似文献
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在界定沙区微区概念的基础上,分析了沙区微区集水的形成、转化以及对干旱沙区生态水文方面的重要作用,综述了国内外对微区集水在土壤水文、土壤发育和微区植被生长等方面的研究动态以及沙区微区集水在农林业和生态修复上的应用,指出沙区微区生态水文过程今后的研究重点在于对微区水文过程做出更加准确的量化分析,提出沙区具有完整意义的水文模型,为准确定量评价沙区水分循环和生态恢复提供理论依据。 相似文献
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高位集水冷却塔是在常规冷却塔的填料下方增设了一层集水装置,研究集水装置的阻力特性对于计算冷却塔通风量具有重要意义。本文采用FLUENT流体计算软件,研究了集水装置气流特性。通过数值模拟计算,得出了集水装置的阻力系数值以及不同填料阻力和集水装置深度对阻力系数的影响均不大;数值计算模型计算结果与已知的试验结果对比表明,两者吻合良好,计算成果可供高位集水冷却塔的研究和设计参考。 相似文献
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A series of laboratory experiments was carried out on a sandy loam soil, for testing the predictive ability of a linearized analytical solution of the kinematic wave equation used for runoff estimation in micro-catchment water harvesting design. The experimental set-up comprised an inclined flume containing the soil sample and a rainfall simulator. The flume represented the Contributing Area (CA) of a micro-catchment. By applying various rainfall intensities, the runoff from the flume was recorded for a variety of conditions, including the initial soil water content and the slope of the flume. Comparison between experimental and predicted runoff hydrographs showed satisfactory agreement. 相似文献
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The performance of a small runoff-basin water-harvesting system (negarim) was evaluated under a typical Mediterranean arid environment in Jordan. Rainfall, runoff, catchment area, soil water storage, and crop evapotranspiration were analyzed as elements of one system. Three micro-catchment areas (25, 50, and 75 m2) and three surface treatment methods (natural, plastic cover, and compaction) were used. Runoff efficiency was evaluated for 16 storms. Storage efficiency was evaluated for eight periods by monitoring soil water balance in the crop root zone. The overall efficiency of the water-harvesting system was determined as the ratio of the amount of water stored and used by the crop to the amount of rainfall received in the catchment area. The overall efficiency of the system varied from over 85% to as low as 7% depending on the size of the catchment and the root zone capacity. Gains in runoff improvement were lost when the soil moisture in the cultivated area was near field capacity. The required ratio of the catchment area to the cultivated area was found to be strongly related to the root zone storage capacity and the rate of consumptive use as well as rainfall-runoff characteristics. 相似文献
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为减少惠州抽水蓄能电站建设期和运行期由于项目施工产生弃渣带来的水土流失,结合水土保持和水工设计技术,选型设计拦渣坝,并对拦渣坝运行期的效果和存在缺陷进行研究,总结归纳惠州抽水蓄能电站拦渣坝在同类抽水蓄能电站工程上的适用性。 相似文献
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A mathematical model to estimate nitrogen (N) effluent from an upland field cultivated with barley, where under-drain pipes were installed 60 cm below the field surface, was developed and N effluents for several rainfall patterns during the cultivation period were analysed. The model is composed of the water drainage model and N cycle model. The water drainage model is made up of Sugawara's tank model in which the field is divided into two soil types, permeable soil and impermeable soil, and macro pore. The N cycle model can calculate the N reactions including nitrification, denitrification, mineralization, immobilization, urea hydrolysis and N transportation in the field. By using this model, N effluents caused by rainfall were analysed and characteristics of N effluent were clarified. The under drainages caused by heavy rains which occur around 60 days after fertilization contribute greatly to the amount of N effluent load during a cultivation period. Also, split application of fertilizer is not effective for the reduction of N effluents under any cultivation conditions, especially in winter crops. A large quantity of N effuses out of the field because the major portion of rainfall in a cultivation period occurs in the latter half of the period. 相似文献
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分布式水文模型对土壤含水量的空间描述能力对土壤墒情模拟、分布式输出等具有重要的意义。但分布式水文模型的土壤含水量空间分布计算,需耗费大量的计算资源。为了提高分布式模型的计算效率,从定性的理论分析和定量的数据比对2个方面,证明蓄水容量曲线和分布式模型中逐单元土壤含水量序列的相关关系,并建立了二者之间的转换公式,据此可以将面平均的土壤含水量转换为空间分布的土壤含水量。用离散蓄水容量曲线法设置分布式模型的土壤含水量初值,并与传统模型预热法进行比较,结果表明两种方法得到的土壤含水量空间分布总体趋势完全一致,次洪模拟效果相同,并且节省了大量的计算资源,极大地提高了分布式模型的计算效率。 相似文献