漳河灌区实时灌溉预报研究

介绍了逐日参考作物蒸发蒸腾量和实际作物蒸发蒸腾量的分析计算与预测方法,提出了水稻需水量预测和实时灌溉预报的通用模型,并对实时灌溉预报的方法、步骤以及所需的实时资料进行了讨论.所提出的计算机程序手段先进,实用方便,通用性强.     

旱作物灌溉用水预测公式

从土壤湿润层水量平衡出发,推导出旱作物灌溉用水预测公式,利用历史实测灌溉用水及同期降雨资料率定有关参数,根据降雨预报资料预测灌溉用水量。方法简便,适用于种植结构不明的灌区,特别是数个灌区构成的灌溉区域。     

抽水灌溉系统站库联合优化调度数学模型

为解决我国南方岗地多级抽水灌溉系统灌溉保证率偏低、系统中工程效益发挥差等问题,以一具体灌溉系统为例,用系统分析的方法建立了大系统站库联合优化调度数学模型.模型中将多维动态规划模型与模拟模型等优化技术相结合,巧妙地解决了灌溉水量时、空协调优化调度问题.实例表明:该模型的应用能充分发挥系统中各骨干工程的作用,提高系统的灌溉保证率.模型为提高类似灌溉系统的灌溉效益提供了新的研究途径.     

应用模拟技术进行区域干旱分析

根据历史资料,应用干旱模拟模型对旱作物进行了区域农业干旱时空分布规律研究,研究典型干旱年的发生、发展和缓解过程,并对旱情的实时监视、跟踪,可能的灾情评估作了初步探讨。     

非充分灌溉制度设计优化模型

研究了缺水地区冬小麦灌溉问题.分析了作物模型,作物水分影响函数,并以农作物产量最大为目标,提出了非充分灌溉制度优化设计二维动态规划模型和相应的动态规划逐次逼近(DPSA)求解方法.针对山东省临沂市小埠东灌区的实际情况进行研究,求得了冬小麦三个典型年不同供水水平的最优灌溉制度、排水过程及相应产量.实例表明,模型及方法是合理的.     

龙潭中型灌区灌溉水量平衡分析

龙潭中型灌区位于辽宁省西部的北票市境内。通过对灌区的可供水源龙潭水库的供水能力进行计算,进而进行灌溉水量平衡分析可知,该灌区灌溉作物为旱田,设计保证率为50%,渠系水利用系数按0.65计算,通过以上分析,上游来水量大于用水量,能满足灌区的灌溉需求。     

最小二乘原理在径流量资料处理中的应用

利用最小二乘原理，研究了实测径流量资料平差处理问题，并推导了参数平差法的具体计算模型，通过计算实例说明了利用此方法可以合理地消除实测径流量计算结果中的偶然误差，解决了实测径流量不同年份各站之间的矛盾，给出了客观、实用、可靠的径流计算结果，并可对实测径流资料进行精度评定和分析。     

安徽淮北农灌区井灌经济技术研究

本文从地下水资源动态转化与供需平衡的角度,以开采量、农田除涝防渍及机井水泵吸程水位为约束条件,井灌区灌溉效益最大为目标,建立了井灌经济模型,优化计算了作物种植组成及充分、非充分灌溉供水保证程度,对井灌工程进行了财务经济分析,提出了经济井径、井深、经济井距等井灌开发方案。     

非线性节水高产优化模型

为研究节水高产的灌溉制度,从研究作物根区土壤水运动及作物腾发规律入手,建立了一个求解作物灌溉制度的非线性优化模型.经实例验证,模型是合理可行的.     

水分胁迫条件下稻田优化灌溉制度的研究

本文通过对非充分灌溉条件下水稻优化灌溉制度如何制定进行了研究。其特点是将作物产量模型与耗水规律模型相结合,以相对产量最高为目标函数,建立了优化决策系统,并利用多目标规划进行求解。该研究成果可使有限的水量在作物生育期内发挥最大的效率,对优化配置水资源,实现农业高效用水具有重要作用。实例研究结果说明,所建模型及求解方法是合理与可行的,不但提高了水分利用效率,还为查哈阳灌区水资源的优化利用提供了科学依据。     

Assessment of factors influencing groundwater-level change using groundwater flow simulation,considering vertical infiltration from rice-planted and crop-rotated paddy fields in Japan

Assessing factors that influence groundwater levels such as land use and pumping strategy, is essential to adequately manage groundwater resources. A transient numerical model for groundwater flow with infiltration was developed for the Tedori River alluvial fan (140 km²), Japan. The main water input into the groundwater body in this area is irrigation water, which is significantly influenced by land use, namely paddy and upland fields. The proposed model consists of two models, a one-dimensional (1-D) unsaturated-zone water flow model (HYDRUS-1D) for estimating groundwater recharge and a 3-D groundwater flow model (MODFLOW). Numerical simulation of groundwater flow from October 1975 to November 2009 was performed to validate the model. Simulation revealed seasonal groundwater level fluctuations, affected by paddy irrigation management. However, computational accuracy was limited by the spatiotemporal data resolution of the groundwater use. Both annual groundwater levels and recharge during the irrigation periods from 1975 to 2009 showed long-term decreasing trends. With the decline in rice-planted paddy field area, groundwater recharge cumulatively decreased to 61 % of the peak in 1977. A paddy-upland crop-rotation system could decrease groundwater recharge to 73–98 % relative to no crop rotation.     

江汉平原旱地和水田土壤镉的吸附与解吸特征及影响因素

为揭示旱地和水田土壤镉的吸附解吸特征,以江汉平原黄豆地、棉花地以及水稻田土壤为研究对象,开展土壤镉的吸附动力学实验、等温吸附?解吸实验以及有机质的影响实验.结果表明:江汉平原土壤对镉的吸附是一个较为复杂的吸附动力学过程且以化学吸附为主,研究区土壤镉的初始吸附速率总体上表现为水田土壤大于旱地土壤;旱地土壤对Cd2+具有较...     

The study of soil acidification of paddy field influenced by acid mine drainage

The acidification of paddy fields was studied in Guizhou Province, China. Affected by acid mine drainage, the pH value of irrigation water was 2.9 with the concentrations of iron and aluminium above 40 mg/L. Based on the pH(H₂O) of topsoil, the paddy fields studied were classified spatially into three zones, the natural zone (pH value from 6.2 to 5.5), the acidified zone (pH value from 5.5 to 4.5), and the seriously acidified zone (pH value from 4.5 to 3.2), respectively. Comparing to the natural zone, the buffering processes for acidification of paddy soil were discussed by considering the changes of calcium, magnesium, potassium and aluminium in soils. The Ca, Mg and K were leached from the soil by the decomposition of carbonate and kaolinite. The leaching of Mg became less with the enrichment of iron in topsoil layer. When the soil pH was below 5.0, aluminium was leached from soil because of the dissolution of alumino silicate minerals. In addition, the hydrolysis of iron and aluminium in soil provided more protons to promote the soil acidification. Furthermore, the buffer capacity of paddy soil was discussed by the results of buffer experiment, based on which the pH buffer curve was drawn and the empirical formula for calculating the acidification rate was developed. Because pH buffer capacity of soil is about 2.78 cmol_c/kg pH for the pH(H₂O) value above 5.0, it is estimated that only another 50 years are needed for the pH(H₂O) of the paddy soil decrease to 3.5 in the acidified zone if the acid water is used for irrigation continuously.     

气候变化下长江中下游水稻灌溉需水量时空变化特征

选择长江中下游单季中稻为研究对象,结合45个气象站1961~2010年逐日气象资料,基于统计降尺度模型(SDSM),生成HadCM3气候模式A2和B2两种情景下各站点参考作物腾发量和降水数据。基于联合国粮食及农业组织(FAO)推荐的作物系数法,并考虑有效性降雨和不同地区深层渗漏量,分析历史和未来的水稻灌溉需水时空变化特征。结果表明:过去50年,除了太湖流域以外的长江中下游大部分区域的参考作物腾发量和水稻需水量都呈显著下降趋势,而显著下降的水稻灌溉需水量主要位于鄱阳湖流域;未来两种情景下,参考作物腾发量、水稻需水量和水稻灌溉需水量均值都呈下降趋势,但水稻灌溉需水量降幅最小;水稻需水量和水稻灌溉需水量在长江中下游地区的变化趋势具有明显的空间异质性,水稻需水量大幅减少的区域由太湖流域向汉江和洞庭湖流域扩展。未来水稻灌溉需水量减少的区域主要分布在太湖流域、汉江流域东部和洞庭湖流域北部,并随时间推移呈扩大趋势。     

Management and environmental constraints to rice yield within a village irrigation system — A case study from Sri Lanka

Management and environmental constraints to rice yield in a paddy tract (lowland rice field) was studied within a village irrigation system in Sri Lanka. The relative importance of water coverage during the critical period and soil fertility variables on the yield variations were analysed. For the upper part of the paddy tract having adequate water supply, environmental and management factors seemed to explain the large variations in yield. For the middle and lower parts, with a shortage of water, water coverage was the only significant explanatory factor.For efficient use of a scarce water supply farmers allocated water first to the upper part, which resulted in water deficiency further down. An alternative strategy for water allocation, where the lower more fertile part of the paddy tract is favoured, would not avoid the risk of water scarcity for the individual farmer but there would be a potential for increase in the total production.     

基于氢氧稳定同位素识别干旱区棉花水分利用来源

棉花是我国西北内陆干旱地区主要的农作物,研究干旱区棉花的水分利用来源对合理制定灌溉制度、实现农业节水灌溉和保证作物稳产高产具有重要意义.在新疆生产建设兵团炮台土壤改良试验站,基于水文监测和氢氧稳定同位素方法分析膜下滴灌棉田土壤水中氢氧同位素的动态变化特征,确定棉花不同生育期及灌溉后的水分利用来源,并应用多水源混合模型(IsoSource模型)定量计算了棉花对不同深度土壤水的利用率.研究结果表明:棉花在蕾期、花期、铃期和吐絮期主要的水分利用来源及利用率分别为0~30 cm(78.2%)、30~60 cm(31.9%)、60~110 cm(32%)、110~220 cm(47.3%),整个生育期内水分利用来源存在由浅变深的规律.膜下滴灌后,棉花调整其水分利用来源,显著增加了0~30 cm浅层土壤水的利用率.综合试验结果表明低额高频的灌溉制度可以提高棉花对灌溉水的利用率.      

砂箱模型模拟休耕田区以砂桩补注地下水对溶质传输影响

水田在休耕期间蓄水,除了可维持水田原有之生态机能外,亦可增加土壤水分涵养与补注地下水.利用砂箱来模拟休耕田区中打入砂桩以补注地下水时,砂桩存在对灌溉水中之溶质在土壤中传输之影响.由试验结果得知当砂桩贯穿牛踏层时可增加水分入渗速率约40倍,相对的,砂桩亦加速溶质在不同土壤层间之传输速率,尤其在牛踏层下方之土壤为砂层时,其影响更为显著.因此,蓄水过程中需注意水源之品质,以避免土壤与地下水受污染.     

不同水肥条件下水稻氮素运移与转化规律研究

针对不同的水肥处理,采用15N示踪方法,观测分析了氮素在稻田的时空分布及运移规律、挥发及淋失损失规律、氮素在水稻植株中的分布特征、稻田氮量平衡等。结果表明:不同灌溉方式下,由于稻田水分状况的差异导致土壤养分时空分布不同,从而影响其对作物的有效性;由于节水灌溉稻田水分相对较少,基质浓度较高,挥发损失高于淹灌。虽然节水灌溉下稻田渗漏液NH₄及NO₃-浓度较淹灌高,但由于此时总渗漏量显著减少,氮的总淋失较淹灌条件少;节水灌溉下,适当增加追肥次数,有利于减少各种氮素养分的损失,提高氮肥利用率;节水灌溉下水稻对氮素的吸收利用率高于淹灌,且有利于氮素养分向稻谷转移。