Effective water management and control for a large scale irrigation/drainage system

大型灌溉/排水系统的有效水管理和控制

基本信息

批准号：
11460110
负责人：
KUBO Naritaka
金额：
$ 6.59万
依托单位：
Tokyo University of Agriculture and Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11460110/
关键词：
Irrigation and drainage Water use efficiency Water management Unsteady flow Numerical simulation Implicit finite difference method

项目摘要

Through four years study by the grant-in-Aid for Scientific Research following results are obtained. (1) About the user-friendly unsteady flow model, we can develop a model based on the implicit finite difference method. We applied the unsteady flow model to the drainage analysis for the Red river Delta in Vietnam, and we can show the effectiveness of the model. We also show that the model can be used as the Tank model for the runoff analysis by combining several interior boundary conditions. (2) About the drainage analysis in a large low-flat area, we selected a floating rice area in the Chao Phraya River Delta in Thailand as the study field. Through the water budget analysis, we examined the retarding capacity of the floating rice area. As the result, we proposed a project to build retarding area by surrounding dykes and to construct regulating reservoirs, and we also showed that the project could solve to some extent two difficult problems of flood during rainy season and drought du … More ring dry season. (3) About the abnormal tidal fluctuation by a construction of a tidal weir in a tidal river, we can solve the phenomena theoretically considering non-linearity of the friction term in the movement equation. As the result, we could show an formula that can calculate approximate amplitude of abnormal fluctuation with regard to the distance from the river mouth. (4) About the flow rate estimation in an irrigation canal by observing water levels, we develop a procedure by use of an unsteady flow model and optimization method. We applied that procedure to the field experiment using Murataka irrigation canal and also to the laboratory experiment by constructing a small-sized model canal. As the result, we verified that the procedure is very effective to estimate flow rate. However, we identified a new problem of treating friction term in case of the very small-scale reduced model experiment. This problem was not solved in this study but should be analyzed in the next step. (5) About the analysis of transient process from one steady state to the other one in an irrigation canal system when hydraulic facilities are controlled, we could solve some phenomena theoretically in some specific conditions. According to the solution, canals can be classified to short and long canals by a representative length obtained through non-dimensional analysis. As the results, we could show that the mechanisms of transient processes are quite different between short and long canals. Namely, in the case of the short canals, the unsteadiness is weakened by waves that go and return, and in the case of the long canals the unsteadiness is weakened by diffusion. Less

通过赠款的四年研究，获得了以下结果的科学研究。（1）关于用户友好的不稳定流程模型，我们可以基于隐式有限差异方法开发模型。我们将不稳定的流模型应用于越南红河三角洲的排水分析，我们可以显示该模型的有效性。我们还表明，该模型可以通过结合多个内部边界条件来用作径流分析的储罐模型。（2）关于在大型低水平区域的排水分析，我们选择了泰国的Chao Phraya河三角洲的浮动大米区域作为研究领域。通过水预算分析，我们检查了浮动大米区域的延迟能力。结果，我们提出了一个项目，以通过周围的堤防和建造监管水库来建立迟滞的区域，我们还表明该项目可以在一定程度上解决雨季和干旱du的洪水困难问题，而干旱的潮流……更多的潮湿季节。（3）关于在潮汐河中造成潮汐奇怪的造成的绝对潮汐波动，我们可以考虑到运动方程中摩擦项的非线性，从理论上解决现象。结果，我们可以显示一个公式，该公式可以计算出距离河口距离的异常波动的近似放大器。（4）关于通过观察水位的灌溉管中的流速估计，我们通过使用不稳定的流量模型和优化方法来开发程序。我们通过构建小型模型管，将该程序应用于现场实验，并将其应用于实验室实验。结果，我们验证了该过程对于估计流量非常有效。但是，在非常小的模型实验的情况下，我们发现了一个新的治疗摩擦项的问题。在这项研究中没有解决此问题，但应在下一步中进行分析。（5）关于控制液压设施时，在灌溉管系统中从一个稳态到另一个稳定状态的瞬态过程分析，我们可以在某些特定条件下从理论上解决某些现象。根据该解决方案，可以通过通过非二维分析获得的代表长度将运河分类为短运河。结果，我们可以证明短管和长管之间的瞬态过程机制截然不同。也就是说，在短运河的情况下，不稳定的波浪会因返回的波浪而削弱，在长管的情况下，不稳定会因扩散而削弱。较少的