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1.
根据作物产量与作物耗水量的关系,考虑了某一次灌水时间提前或推后对产量的影响,不同灌水次数以及相同灌水次数因不同灌溉地块灌水时间有先有后使得产量不同等几个因素,以灌区全部灌溉地块综合平均产量最大为目标函数,建立了灌区灌溉配水优化模型。通过对庞庄水库灌区冬小麦生长期灌溉具体条件进行优化计算,获得了比较满意的结果。  相似文献   

2.
作物水分生产函数及灌溉制度优化的研究进展   总被引:2,自引:0,他引:2  
阐述了作物水分生产函数的基本原理和一些典型模型,并对其在灌溉方面及不同阶段缺水对作物生物量累积的后效性影响等方面的研究,以及可行性分析及地区移用性研究加以探讨。对作物灌溉制度优化模型以及作物优化灌溉制度设计方法研究加以探讨,分析了目前模型中指数取值研究不足等问题。为合理利用有限水资源,达到最大的作物产量或产值,实现有限水量在作物生长期及作物间的合理配置提供依据。  相似文献   

3.
基于作物水分生产函数下的限额灌溉制度优化研究   总被引:4,自引:0,他引:4  
通过对小麦、玉米、棉花等主要农作物的分阶段受旱试验,获得了三年的限额灌溉试验观测数据;采用非充分灌溉条件下的土壤水分运动理论分析试验数据,建立了限额灌溉条件下的作物蒸发蒸腾模型。结合试验数据分析水分亏缺对作物产量的影响,采用多元回归分析法求解水分生产函数模型参数。采用动态规划法研究了水资源不足条件下的限额灌溉制度的多阶段优化法。研究成果表明,在产量能达到充分灌溉条件下产量的90%的情况下,可节约灌溉用水40%,能为水资源极其短缺地区的农业高效用水提供有力的技术支撑。  相似文献   

4.
水稻水,肥生产函数及优化灌溉模式   总被引:7,自引:1,他引:6  
本文根据作物生长的动力学原理,结合控制灌溉田间试验,对水稻生长进行数值模拟计算,救是随时间而变的动态产量递推模型,然后采用系统分析方法,将动态产量转化随水,肥而变的产量模型(水,肥生产函数),并求得优化灌溉模式,实例分析了表明建议的数学模型是合理可行的。  相似文献   

5.
干旱区作物——水模型的选择   总被引:2,自引:0,他引:2  
作物———水模型的选择是制定节水灌溉制度的重要环节,也是实现水资源优化利用的主要依据。本文通过干旱区节水灌溉试验研究,介绍了干旱区作物———水模型的选择过程,并对原始模型进行了修正,从而为干旱区节水灌溉制度的制定提供了依据。  相似文献   

6.
文章综述了我国主要农作物水分生产函数的研究现状、各个模型的优缺点以及适用情况等,明确作物水分生产函数在灌溉制度优化中的应用,并说明在应用过程中存在的问题以及解决问题的对策等,为作物在有限水资源情况下制定合理灌溉制度、有效促进作物生长从而提高作物产量和水分利用效率提供理论依据。  相似文献   

7.
亏缺灌溉的国外研究进展   总被引:1,自引:0,他引:1  
亏缺灌溉(DI)将水分限制在作物对干旱敏感的生长阶段,最大限度提高水分生产率,稳定作物产量。文章总结了亏缺灌溉国外研究成果,发现亏缺灌溉可提高农作物水分生产率,维持产量正常水平。基于国外亏缺灌溉的研究成果,建议我国学者应引入作物水分生产力模型,定量研究亏缺灌溉的作用机理。  相似文献   

8.
盈科灌区是黑河流域中游绿洲典型灌区之一,该灌区农业用水效率较低,农业用水矛盾十分突出。制种玉米是灌区主要种植作物,研究制种玉米的优化灌溉制度对实现该区域农业用水可持续发展具有十分重要的意义。利用分布式作物模型AquaGIS模型,基于盈科灌区土壤质地的空间变异性对该灌区制种玉米灌溉制度进行了优化,提出了适合灌区实际配水情况的最佳灌溉制度。通过灌溉制度优化,灌区制种玉米蒸散发量减少36~53mm,水分生产率WPET增加5%左右,灌溉水生产率WPI增加25%~48%,极大地提高了灌区农业用水效率。同时,对该灌区不同水文年灌溉制度进行优化,综合对比灌区制种玉米WPET、WPI和产量,其中丰水年灌溉3次、平水年灌溉4次、枯水年灌溉5次可以实现农业用水效率最高,为灌区高效节水灌溉提供理论指导。  相似文献   

9.
玉米水分生产函数试验研究温守光,赵大玉(山西省潇河水利管理局灌溉试验站)作物水分生产函数,是指水与作物产量之间的数量关系。过去对玉米产量与水分关系的研究,均侧重于从产量与全生育期蒸发蒸腾量关系而建立的数学模型。这种模型的不足之处是掩盖了灌水时间影响作...  相似文献   

10.
对作物水分生产函数的概念、分类、研究状况及其在节水高产优化模型中的应用作系统介绍。文中将作物水分生产函数分为最终产量模型和动态产量模型,分别给予介绍。同时介绍作物节水高产优化模型,并通过实例进行分析,指出以作物水分生产函数为基础制定的优化模型是解决农业用水紧张、提高水资源利用率,实现从水源到作物完全节水的一条有效途径。  相似文献   

11.
节水控盐灌溉制度的优化设计   总被引:12,自引:1,他引:11  
本文根据作物水盐动态响应函数,分析了作物生长与土壤水盐运动关系,建立了节水、控盐、高产灌溉制度优化设计模型,为节水灌溉和微咸水利用提供了决策依据。实例分析表明,本文提供的模型及方法是合理的;实施节水、控盐灌溉制度能带来明显的经济效益和环境效益。  相似文献   

12.
确定农田灌溉定额的三种优化目标的比较   总被引:10,自引:0,他引:10  
本文针对灌水量与作物产量间所经常表现出的二次抛物线的情况,就分别以追求产量、生产效率和生产弹性系数的最大值为目标的农田灌溉定额的判定结果进行了比较。研究表明,使灌水生产效率达到最大的灌溉定额只有当作物在雨养条件下无产量形成时才存在,而使生产弹性系数达到最大的灌溉定额只有当作物在雨养条件下有产量形成时才存在。考虑经济因素后的结果与此类似,区别在于此时不仅与雨养条件下能否形成产量有关,还与除灌水以外的单位面积固定费用、单位产量及单位灌水量的综合价格有关。文章同时认为,对于线性的产量与灌水量关系而论,在灌水量的取值区间内,三种优化目标的解是不存在的。  相似文献   

13.
在华北平原中国农业大学东北旺实验田开展了水肥耦合灌溉实验,设置了传统和优化水肥4个组合处理,同时应用作者提出的联合模拟模型SPWS对2000年夏玉米生育期内的土壤水分、氮素转化运移以及水氮限制条件下夏玉米的叶面积指数、干物重、吸氮量及籽粒产量进行了模拟,模拟结果与实测数据均吻合良好。水氮平衡分析结果表明,优化灌溉和优化施肥管理措施均能明显减小水分渗漏、硝酸盐淋失和氮素的气体损失,且均有不同程度的增产作用,其中优化水肥处理下水氮利用率分别为1.33kg/m3和31.6kg/kgN,为4个组合处理中最高。  相似文献   

14.
Water demand for irrigated agriculture is increasing against limited availability of fresh water resources in the lower reaches of the Amu Darya River e.g., Khorezm region of Uzbekistan. Future scenarios predict that Khorezm region will receive fewer water supplies due to climate change, transboundary conflicts and hence farmers have to achieve their yield targets with less water. We conducted a study and used AquaCrop model to develop the optimum and deficit irrigation schedule under shallow groundwater conditions (1.0–1.2 m) in the study region. Cotton being a strategic crop in the region was used for simulations. Capillary rise substantially contributes to crop-water requirements and is the key characteristic of the regional soils. However, AquaCrop does not simulate capillary rise contribution, thereby HYDRUS-1D model was used in this study for the quantification of capillary rise contribution. Alongside optimal irrigation schedule for cotton, deficit strategies were also derived in two ways: proportional reduction from each irrigation event (scenario-A) throughout the growth period as well as reduced water supply at specific crop growth stages (scenario-B). For scenario-A, 20, 40, 50 and 60 % of optimal water was deducted from each irrigation quota whereas for scenario-B irrigation events were knocked out at different crop growth stages (stage 1(emergence), stage 2 (vegetative), stage 3 (flowering) and stage 4 (yield formation and ripening)). For scenario-A, 0, 14, 30 and 48 % of yield reduction was observed respectively. During stress at the late crop development stage, a reduced water supply of 12 % resulted in a yield increase of 8 %. Conversely, during stress at the earlier crop development stage, yield loss was 17–18 %. During water stress at the late ripening stage, no yield loss was observed. Results of this study provide guidelines for policy makers to adopt irrigation schedule depending upon availability of irrigation water.  相似文献   

15.
作物缺水条件下灌溉供水量最优分配   总被引:35,自引:1,他引:34  
针对灌区水源短缺情况,建立了一种对有限水量在多种作物之间进行最优分配的两层分解协调模型:第一层为基于作物水分生产函数,求解单作物非充分灌溉条件下最优灌溉制度的动态规划模型;第二层为将有限水量在多种作物之间进行最优分配的动态规划模型实例计算表明,模型是合理可行的  相似文献   

16.
Irrigated agriculture is the largest consumer of water, with high significance in India as the majority of its people depend on it. Rainfall uncertainties, and uneven distribution of utilizable water over space and time, have presented a serious challenge to irrigation water management and crop production. Surface water reservoirs play a major role in supplying irrigation water and also addressing uneven water distribution to some degree. Varying water requirements for different crops under multiple canals, however, requires that planners develop an optimal crop planning for the efficient operation of a multireservoir irrigation system. The spatial and temporal water transfer within a multireservoir irrigation system necessitates integrated operation of all the involved reservoirs. Thus, integrated operation of a multireservoir system is a fundamental requirement for efficient irrigation water management, and also become a key issue for sustainable agricultural development. This study derived an optimal crop plan for the integrated operation of a complex multireservoir system with intrabasin water transfer, using a multiobjective fuzzy linear programming (MOFLP) approach. The MOFLP model resulted in a level of satisfaction of 0.46, with an irrigation intensity of 102.18%, and a total crop area of 149 232.10 ha. The optimal policies were furthermore assessed with various statistical indicators with a simulation model, indicating they are performing well, with high reliability and resilience for longer periods.  相似文献   

17.
This paper focuses on the analysis of the effects of groundwater table control under different irrigation water amounts on the water and salinity balance and on crop yield. Two experimental areas, the Pingluo and Huinong experimental sites, were selected to collect the required data. The agro-hydrological model Soil Water-Atmosphere-Plant (SWAP) was used to analyse the water flows and salt transport processes for different groundwater levels and irrigation scenarios. Six scenarios, which resulted from different groundwater table regimes combined with different irrigation amounts, were simulated. The results show that high groundwater tables due to the excessive irrigation are the main cause of the large amount of drainage water and low crop yield;reducing irrigation water without a lower groundwater table will not lead Io a large reduction of the drainage water, and will reduce the crop yield even more; to lower the groundwater table is a good measure to control the drainage water and increase crop yield.  相似文献   

18.
To meet the anticipated increase in global demand for food and fibre products, large areas of land around the world are being cleared and infrastructure constructed to enable irrigation, referred to herein as ‘greenfield irrigation’. One of the challenges in assessing the profitability of a greenfield irrigation development is understanding the impact of variability in climate and water availability and the trade-offs with scheme size, cost and the sensitivity of crop yield to water stress. For example, is it more profitable to irrigate a small area of land most years or a large area once every few years? And, is it more profitable to partially or fully water the crop? This paper presents a new method for efficiently linking a river system model and an agricultural production model to explore the financial trade-offs of different management choices, thereby enabling the optimal scheme area and most appropriate level of farmer risk to be identified. The method is demonstrated for a hypothetical but plausible greenfield irrigation development based around a large dam in the Flinders catchment, northern Australia. It was found that a dam and irrigation development paid for and operated by the same entity is not, under the conditions examined in this analysis, economically sustainable. The method could also be used to explore the impact of different management strategies on the agricultural production and profitability of existing irrigation schemes within a whole of river system context.  相似文献   

19.
宁夏扬黄灌区玉米限额补充灌溉制度研究   总被引:1,自引:1,他引:1       下载免费PDF全文
结合宁夏中部干旱补灌区限额供水的特点,集成覆盖保墒技术、大田微集水技术、限额补充灌溉技术,开展玉米限额灌溉制度试验研究。综合分析作物需水关键期、限额灌溉技术、土壤含水率、产量、水分利用效率,提出宁夏中部干旱区适宜的玉米限额灌溉制度。  相似文献   

20.
土壤水盐是影响干旱盐渍化地区农作物产量的重要因素,近年来内蒙古河套灌区开始推广种植冬小麦,在重点考虑不同土壤盐分状况,通过设计不同盐渍化土壤条件下冬小麦灌溉制度方案,分析田间对比试验数据成果,在此基础上利用ISAREG模型开展不同方案的优化决策研究。研究表明:考虑盐分胁迫和冻融因素条件下,ISAREG模型可以对河套灌区冬小麦进行灌溉制度优化;通过建立基于水盐胁迫的ISAREG灌溉制度模型,制定了不同盐渍化条件下考虑土壤冻融的冬小麦优化灌溉制度;优化得出河套灌区冬小麦全生育期灌水定额情况为:当土壤含水率低于适宜含水率的85%时进行灌水,通过ISAREG模型即可推导出不同含盐土壤的灌水定额与灌水日期;土壤含盐量较低的情况下冬小麦全生育期适宜灌水5次,优化灌水定额分别为66、54、79、83和83 mm,灌溉定额365 mm;中度含盐土壤冬小麦全生育期适宜灌水5次,优化的灌水定额分别为78、54、90、97和97 mm,灌溉定额为416 mm。  相似文献   

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