大型灌区闸系分布式监控系统设计

本文介绍了一种灌区闸系分布式监控系统的设计方法。简单介绍了DCS系统的发展和结构形式,对该分布式控制系统的设备选型和软件设计作了详细说明,该控制系统的使用是实现大型灌区综合信息化的重要前提。     

农业大棚的温湿度控制系统

为了适应作物生长过程中所需参数值不是精准值的实际并且尽可能取得较理想的控制效果 ,系统采用了模糊控制技术。实现对棚内的空气湿度、土壤湿度及温度三项主要灌溉参数的自动检测及显示。由键盘输入三项灌溉参数的参考值 ,系统的模糊逻辑自动控制相应炉、泵通断 ,调节棚内温湿度 ,使其趋于参考值。器件选择留有余地 ,便于扩展。     

Generalization of ETo ANN Models through Data Supplanting

This paper describes the application of artificial neural networks (ANNs) for estimating reference evapotranspiration (ETo) as a function of local maximum and minimum air temperatures as well as exogenous relative humidity and reference evapotranspiration in different continental contexts of the autonomous Valencia region, on the Spanish Mediterranean coast. The development of new and more precise models for ETo prediction from minimum climatic data is required, since the application of existing methods that provide acceptable results is limited to those places where large amounts of reliable climatic data are available. The Penman-Monteith model for ETo prediction, proposed by the FAO as the sole standard method for ETo estimation, was used to provide the ANN targets for the training and testing processes. Concerning models which demand scant climatic inputs, the proposed model provides performances with lower associated errors than the currently existing temperature-based models, which only consider local data.     

Sustainable Root Zone Salinity and Shallow Water Table in the Context of Land Retirement

This study uses five years of field data from the Land Retirement Demonstration Project located in western Fresno County of California to develop a comprehensive theoretical and numerical modeling framework to evaluate the specific site conditions required for a sustainable land retirement outcome based on natural drainage. Using field data, principles of mass balance in a control volume, the HYDRUS-1D software package for simulating one-dimensional movement of water, heat, and multiple solutes in variably-saturated media, and a model-independent parameter optimizer, the processes of soil water and solute movement in root zone and deep vadose zone were investigated. The optimization of unsaturated soil hydraulic parameters and downward flux (natural drainage) from the control volume against observed vadose zone salinity levels and shallow groundwater levels yield difficult to obtain natural drainage rate as a function of water table height within the control volume. The results show that the unsaturated soil hydraulic properties and the downward flux from the soil profile are the critical parameters. A “natural drainage approach” to sustainable land management for drainage-impaired land is proposed. With this approach it is feasible to design a sustainable land use regimen for drainage-impaired lands in general and retired lands in particular.     

River Hydrograph Retransmission Functions of Irrigated Valley Surface Water–Groundwater Interactions

Storage and release functions of western U.S. traditional river valley irrigation systems may counteract early and rapid spring river runoff associated with climate variation. Along the Rio Grande in northern New Mexico, we instrumented a 20-km-long irrigated valley to measure water balance components from 2005 to 2007. Hydrologic processes of the system were incorporated into a system dynamics model to test scenarios of changed water use. Of river water diverted into an earthen irrigation canal system, some was consumed by crop evapotranspiration (7.4%), the rest returned to the river as surface return flow (59.3%) and shallow groundwater return flow that originated as seepage from canals (12.1%) and fields (21.2%). The modeled simulations showed that the coupled surface water irrigation system and shallow aquifer act together to store water underground and then release it to the river, effectively retransmitting river flow until later in the year. Water use conversion to nonirrigation purposes and reduced seepage from canals and fields will likely result in higher spring runoff and lower fall and winter river flow.     

Discharge Capacity of Labyrinth Side Weir Located on a Straight Channel

Side weirs, also known as lateral weirs, are flow diversion devices widely used in irrigation as a head regulator of distributaries and escapes, land drainage, and urban sewage systems. The studies on the subject have been generally focused on rectangular and triangular side weirs located on a straight channel. However, the same is not true for labyrinth side weirs. The current studies deal with sediment transport and scour problems around side weirs and lateral structures. The investigation of the hydraulic effects of labyrinth side weirs to increase discharge capacity of them has been studied in this particular work. In the study, 2,830 laboratory tests were conducted for determining discharge coefficient of labyrinth side weirs, and results were analyzed to find the influence of the dimensionless weir length L/b, the dimensionless effective length L/?, the dimensionless weir height p/h1, triangular labyrinth side weir included angle θ, and upstream Froude number F1 on the discharge coefficient, water surface profile and velocities in the channel along the side weir. It has been found that discharge coefficient of labyrinth side weirs gives pretty higher coefficient value compare to that of classical side weirs and a reliable equation for discharge coefficient of labyrinth weirs is presented. Discharge coefficient of the labyrinth side weir is 1.5–4.5 times higher than rectangular side weir.     

Energy and Momentum Velocity Coefficients for Calibrating Submerged Sluice Gates in Irrigation Canals

There is renewed interest in developing calibration methods for gates operating in submerged conditions in irrigation canals. In the present study, a new method based on a generalization of the standard energy-momentum method that accounts for variations in the energy and momentum velocity coefficients is proposed, for the following reasons. First, it was found that the assumption of uniform submerged jet velocity to account for the kinetic energy head and momentum flux is in reality equivalent to assuming a parabolic relationship between the Coriolis and Boussinesq coefficients. Second, literature investigations showed that the coefficients for the downstream side of submerged gates are notably greater than unity, and the implicit parabolic relationship between these coefficients in the standard energy-momentum method is inadequate, at least for high submergence conditions. The proposed energy-momentum method was evaluated using the data obtained from four gates operating in an irrigation canal in Southern Spain. Improvements in accuracy compared to the standard energy-momentum method (with a constant contraction coefficient Cc = 0.61) were obtained. The results indicate that the calibration of coefficient approach provides a means to improve the energy-momentum method by (indirectly) accounting more accurately for nonuniform velocity effects in the energy-momentum equations.     

洛惠渠灌区东干渠流泥病害治理

通过东干渠流泥病害对灌区的危害、形成原因的分析,提出了针对不同地下水位采用不同的治理措施.     

基于K-Means聚类算法的灌区人居景观特征研究分析 ——以世界灌溉工程遗产东风堰为例

名列首批世界灌溉工程遗产的东风 堰，在过去360余年里，为夹江的农业发展、生 态保护、人居环境改善产生了巨大效益。基于灌 区人居景观体系理论、罗西类型学、皮尔逊相关 性分析及K-Means聚类算法对东风堰灌区人居 景观体系格局特征与发展现状进行研究。首先 依据人居景观体系理论甄别出潜在三大研究要 素“水系—农田—村落”，对相关数据筛选、清 理和整合后，运用类型学理论和皮尔逊相关系数证明了三大要素的承载关系具有高度相关性和耦合性。进而，较为创新地运用计算机无监督学 习K-Means聚类算法解析现代灌区人居景观体系：以灌区内的行政村①为基本单元，选择村域内 水系数、灌溉农田面积和承载人口数为三组数据指标，对灌区“水系—农田—村落”景观体系的 关系迭代计算归类，得到三类村落的聚类阈值。进一步量化村落聚类关系，运用景观生态学及图 底关系理论分析各类村落异质性特征及验证其水资源安全及农业生产模式的合理性，并给出各 类村落的人均拥水量评估标准建议，总结出灌区城乡建设应遵循“以水定产，以产定人”的规划 原则，同时提出了不同水资源条件下的产业模式策略。为东风堰世界灌溉工程遗产传承提出保护 建议、灌区村落未来发展提供相关参考值，并为其他同类型灌区的人居环境建设提供典例。     

灌区的风景：国土空间开发视野下的传统风景营建

囿于我国气候及地形地貌因素，对水资 源进行时空调配及管理是农业生产发展的必要 条件，由此发展出以灌溉和调蓄为主的水利工 程，形成了以人工控制流量和水位的水文流域 单元——灌区。经过数千年的发展，灌区已成为 我国以农业为基础的国土空间开发基本模式。 首先简述我国灌区的形成及发展、确定陂塘灌 区、堰坝灌区和泉（井）灌区这3 种基本类型、 分布和特征，在此基础上分析其对风景审美及 风景营建的影响。然后以北京三山五园为例，剖 析其农业生产、聚落布局、园林营建皆与水利系 统密切相关，是具有陂塘灌区和泉（井）灌区特 征的国土空间开发的案例。最后，横向对比英 国与伊斯兰造园体系，论述不同地区迥异的地 理和水文条件塑造了以农业为主导的国土空间 开发方式，并进一步影响了传统的风景营建。文 章为理解我国传统的风景营建方式提供了新视 角，有助于其进一步的保护与发展。