Irrigation Planning using Genetic Algorithms

The present study deals with the application of Genetic Algorithms(GA) for irrigation planning. The GA technique is used to evolve efficient cropping pattern for maximizing benefits for an irrigation project in India. Constraints include continuity equation, land and water requirements, crop diversification and restrictions on storage. Penalty function approach is used to convert constrained problem into an unconstrained one. For fixing GA parameters the model is run for various values of population, generations, cross over and mutation probabilities. It is found that the appropriate parameters for number of generations, population size, crossover probability, and mutation probability are 200, 50, 0.6 and 0.01 respectively for the present study. Results obtained by GA are compared with Linear Programming solution and found to be reasonably close. GA is found to be an effective optimization tool for irrigation planning and the results obtained can be utilized for efficient planning of any irrigation system.     

梧桐河灌区灌溉水资源平衡研究

对梧桐河灌区水资源系统进行概化模拟,通过水资源平衡方程对不同频率下的水量要素进行了计算,并对灌区水资源进行分析,得出不同年份灌区地表水、地下水联合运用的灌溉方案.     

塔河灌区地下水均衡分析

水资源是西部地区战略性经济资源,加强水资源管理、实现水资源可持续性是西部地区的战略目标。近年来,我国干旱天气频繁,西北地区水资源极度匮乏,加之水资源利用效率较低,严重阻碍了当地农业经济的发展。灌区是塔里木河流域经济发展的重要部分,也是区域环境保护的重要依靠。地下水是水资源的重要组成部分,由于当地缺乏科学的地下水开采规划,导致地下水过度开发,甚至出现了一系列恶劣的环境问题。因此,对灌区地下水进行均衡分析,并计算地下水补给量和排泄量具有重要意义。通过对灌区地下水进行科学计算,并进行了供需水量平衡分析。分析表明,塔河灌区地下水处于负均衡状态。     

作物需水量与灌溉制度模拟

从作物需水量的基本概念出发，以水量平衡原理为基础，建立了模拟农田根层土壤水循环的计算机模型-ISAREG.这一模型具有多种功能，可模拟根层土壤水分变化，评价给定的灌溉制度，计算作物需水量和灌溉需水量，也可用以制订多种供水限制条件下的优化灌溉制度．用望都灌溉试验站的小麦、玉米、棉花3种作物两年的试验观测资料对上述模型进行了验证．     

MATLAB遗传算法工具箱(GAOT)在水资源优化计算中的应用

阐述了遗传算法的基本原理,对MATLAB遗传算法工具箱（GAOT）的参数使用进行了详细介绍,探讨了MATLAB遗传算法工具箱（GAOT）在水资源非线性规划和多目标规划时的应用,并用简单实例证明了这种应用具有良好的通用性、可行性和简便性,可以得到较满意的优化计算结果。     

Benefit and Risk Balance Optimization for Stochastic Hydropower Scheduling

Limited by inflow forecasting methods, the forecasting results are so unreliable that we have to take their uncertainty and risk into account when incorporating stochastic inflow into reservoir operation. Especially in the electricity market, punishment often happens when the hydropower station does not perform as planned. Therefore, focusing on the risk of power generation, a benefit and risk balance optimization model (BRM) which takes stochastic inflow as the major risk factor is proposed for stochastic hydropower scheduling. The mean-variance theory is firstly introduced into the optimal dispatching of hydropower station, and a variational risk coefficient is employed to give service to managers’ subjective preferences. Then, the multi-period stochastic inflow is simulated by multi-layer scenario tree. Moreover, a specific scenario reduction and reconstruction method is put forward to reduce branches and computing time accordingly. Finally, the proposed model is applied to the Three Gorges Reservoir (TGR) in China for constructing a weekly generation scheduling in falling stage. Compared to deterministic dynamic programming (DDP) and stochastic dynamic programming (SDP), BRM achieves more satisfactory performance. Moreover, the tradeoffs for risk-averse decision makers are discussed, and an efficient curve about benefit and risk is formed to help make decision.     

榕南灌区水量平衡计算分析

进行灌区来，用水量平衡计算，作为规划工程和工程规模的依据，对保证灌区耕地用水具有重要意义。     

文峪河灌区未来灌溉用水量平衡分析及对策

根据灌区水土资源开发利用现状,分析未来保障粮食安全对灌溉发展的需求及灌区水资源对粮食生产的支撑能力,提出未来灌溉发展潜力,进行水土资源平衡状况分析并提出对策。     

滴灌节水工程水资源平衡分析

节水滴灌和节水增粮行动是中央着眼经济社会发展全局实施的重大专项行动,节水滴灌和节水增粮工程项目的实施已成为现代农业可持续发展的必然选择。绥中县2013年省滴灌项目计划发展高效节水灌溉面积6.67 km2,全部为果树,采用管灌模式。通过滴灌节水工程的实施,实现项目区灌溉管网化,有利于水资源的优化配置和生态环境的改善,有利于提高经济效益、社会效益和生态效益,改善劳动条件,减轻劳动强度,促进农业产业化和农村经济的发展。     

Operation Policies through Dynamic Programming and Genetic Algorithms,for a Reservoir with Irrigation and Water Supply Uses

Water Resources Management - In this study, operation policies were obtained for a reservoir in Michoacán, Mexico, used for irrigation and domestic water supplies. The main purpose of these...     

利用土方平衡原理对输水渠进行优化设计的实践

运用土方平衡原理,结合远距离跨流域调水工程输水干渠设计经验,总结出影响渠道开挖与填筑工程量的主要因素为挖深和筑高,次要因素为渠道底宽和堤顶宽度。针对主次因素,选择适宜的地形及渠道输水坡降,对输水渠平面设计及纵横断面设计进行了全面优化,成功地解决了输水渠弃借土量大、占地多等问题,取得了较大的经济效益、社会效益和环境效益。     

浑水灌溉下土壤水分入渗规律研究综述

目前,国外土壤水分连续入渗研究主要集中在Green-Ampt模型的修正以及Philip、Parlange入渗方程的求解两方面。国内学者对浑水连续入渗的研究认为:浑水与清水入渗的差异主要是浑水中物理性黏粒的存在引起的,浑水入渗模型以通过浑水灌溉试验进行拟合而得到的经验公式为主;对浑水波涌灌间歇入渗研究认为,不同泥沙粒度组成的浑水间歇入渗能力均小于同条件下的浑水连续入渗能力,且减渗率随入渗周期数的增加而增大。今后应开展不同灌水方式、多种影响因素下的浑水灌溉研究。     

灌溉与供水水库调度图编制方法的改进研究

应用《水库调度设计规范》编制灌溉与供水调度图时,经多次调度图检验和修改后还不符合设计要求。为解决这一问题,提出了时历法长系列连续计算,先计算灌溉或供水降低供水线,再计算保证供水线,使降低供水区和保证供水区协调,统一年调节水库和多年调节水库调度图的编制办法等改进措施。通过工程实践检验,表明改进方法可以提高灌溉与供水调度图编制的合理性与准确性,能满足灌溉与供水的降低供水和保证供水要求,水库调度结果符合灌溉与供水设计保证率,并能控制设计保证率外灌溉与供水破坏程度。灌溉与供水调度图可一次性准确编制完成,避免了对调度图进行反复检验和修改。     

基于遗传算法的树状灌溉管网优化设计

根据树状灌溉管网的特点,应用基于整数编码的遗传算法进行了重力和泵站加压的树状灌溉管网的优化设计。该方法操作简单、实用,易于实现,有较高的可行性。在计算机实现过程中采用VB和MATLAB混合编程,软件可脱离MATLAB独立运行。     

井灌区地下水动态模拟的面状井系--水均衡综合模型

以亳州市城北乡灌区为实例 ,采用面状井系模型和水均衡模型 ,来模拟灌区地下水动态变化 ,两个模型结果相互印证 ,所得的结果是可靠的 ,有实际应用意义 ,可推广应用于水文地质条件类似地区     

施工导流建筑物优化退火遗传算法

施工导流建筑物优化设计是一个复杂的非线性约束优化问题．针对传统优化方法的局限性，提出了施工导流建筑物优化设计的退火遗传算法，即改进遗传算法；保存每代的最优个体，并且引入模拟退火技术，不仅确保了解的最优性，而且克服了一般二次型罚函数收敛性能不好的缺点．实例验证了此法应用于施工导流建筑物优化设计的可行性，同时通过与一般二次型罚函数遗传算法的比较，说明本方法具有更好的收敛性能．     

基于遗传算法的灌区渠系优化配水模型研究

为了使灌区配水获得更好的效果,通过改进传统"定流量,变历时"渠系运行方式的轮灌优化配水模型,以灌区配水渠道输水时间最短和各个轮灌组合持续引水时间差异最小建立了双目标函数,采用层次分析法确定各目标函数权重系数,然后根据各目标函数权重系数把双目标函数转化为单目标函数,最后通过遗传算法对单目标函数进行求解,确定了灌区最优轮灌组组合。实例计算结果表明:采用渠系优化配水方法进行轮灌组合优化,缩短了配水渠道输水时间,提高了水资源利用率,取得了较好的配水效果。     

Irrigation Scheduling Optimization for Cotton Based on the AquaCrop Model

To improve irrigation efficiency, it is important to optimize agriculture irrigation scheduling. The objectives of this study were to evaluate the AquaCrop model for its ability to simulate cotton in the North China Plain and optimize irrigation strategies. The AquaCrop model was calibrated using 2002–2009 data and validated using 2010–2014 data. Root mean square error (RMSE), mean absolute error (MAE) and residual coefficient method (CRM) were used to test the model performance. The model calibrated for simulating cotton yield had a prediction error statistic RMSE of 0.152 t hm^?2, MAE of 0.123 t hm^?2 and CRM of 0.120. On validation, the RMSE was 0.147 t hm^?2, MAE was 0.094 t hm^?2 and CRM was 0.092. The goodness-of-fit values for the calibration and validation data sets indicated that the model could be used to simulate cotton yield. The analysis of irrigation scenarios indicated that the highest irrigation water productivity could be obtained by applying one irrigation at the seedling stage in a wet year, two irrigations, at the seedling and squaring stages, in a normal year and three irrigations, at the seedling, squaring and flowering stages, in a dry year. These results could be useful to the government in determining reasonable, well-timed irrigation for agricultural regions.

     

盐碱地膜下滴灌土壤水盐变化规律试验分析

膜下滴灌技术是一种既节约水资源又能适时调控土壤水盐运移的灌溉技术,在新疆已得到普及推广。在田间情况下,研究盐碱地膜下滴灌土壤水盐变化规律,对合理控制盐碱地土壤盐分具有重要的指导意义。试验结果表明,随着灌水时间和灌水量的增加,盐碱地上层土壤水盐整体呈现下降趋势,待灌水期结束后,盐分又逐步回升。