供水水库群蓄供水次序与调度图双层优化研究

水库群供水规则中蓄供水次序与调度图彼此影响,如何实现二者联合优化是供水调度的难点。为此,提出了供水水库群蓄供水次序与调度图双层优化方法。首先合理拟定不同蓄供水次序,其次求解各次序对应最优调度图,最后通过模拟调度比选最佳蓄供水次序与调度图组合。应用该方法对宝鸡峡灌区六库混联供水系统开展了实例研究。结果表明,若上游水库先蓄水且先供水或下游水库先蓄水且先供水均会增大灌区缺水率、降低供水空间公平性,最优蓄供水次序为上游水库先蓄水、下游水库先供水。较现状调度方案,采用最优蓄供水次序及对应调度图组合可有效缓解灌区缺水状况,缩小分区供水效益的差异。本方法为水库群蓄供水次序与调度图联合优化提供了可行途径。     

Improving Wheat Productivity in Pakistan: Econometric Analysis Using Panel Data from Chaj in the Upper Indus Basin

Abstract

Increasing water scarcity, degradation of land and water resources, continuing low agricultural productivity, and increasing populations are posing the largest ever challenges for development of agricultural economies in many developing countries including Pakistan. Using panel data from irrigated settings in Chaj sub-basin of the Indus basin in Pakistani Punjab, we attempt to: (a) analyze the causes of low productivity; (b) disentangle factors (both land, water and other factors) contributing to productivity variations; and (c) identify limits and opportunities for narrowing productivity gaps and increasing overall wheat production, with a view to enhance food security for the poor. The results of the study indicate that locational inequities in distribution of canal water, use of groundwater of varying quality, differences in use of seed varieties, and other inputs lead to significant variations in wheat productivity. Key implications are that large gains in wheat productivity are possible by (a) improving the production environment at the tail-end through integrated water management practices; (b) adjusting the mix of canal and groundwater use; and (c) using technological interventions to improve the adoption of modern wheat varieties and dissemination of knowledge on planting dates and timings and application rates of inputs, especially water and fertilizer. Not only such interventions are economically, financially, and environmentally desirable, they are also pro-poor. What is needed is a strong political will and commitment.     

洛惠渠灌区渠道衬砌现状与思考

通过陕西关中洛惠渠灌区渠道衬砌现状及存在的问题 ,总结性的提出了今后渠道防渗工作中应注意的问题与措施     

农田水利规划的阵矩分析评价法

农田水利规划涉及经济、社会、环境等多方面的影响，是一个比较复杂的系统，用常规的评价方法，难以综合各种因素的影响。而采用矩阵分析法，可以充分考虑制约条件，综合评价评价规划方案的获益能力，并可根据评价指标看出规划在各年中实施的潜力和存在的薄弱环节，判断规划方案的优劣，通过实例说明，矩阵分析评价可以获得满意的结果，具有一定的实用价值。     

黄河三角洲典型灌区实现泥沙长距离输运的原因分析

小开河引黄灌区运行10a,输沙干渠基本处于冲淤平衡,未进行过大面积清淤,实现了泥沙长距离输运的前期设计目标。引水引沙条件、渠道边界条件,支渠与沉沙池运行情况均是影响小开河灌区泥沙长距离输运的主要因素;加大引水流量,降低引水含沙量,合理调整渠道断面形态,减小渠道糙率,科学调控支渠、沉沙池运行状况,均是提高灌区输沙干渠水流挟沙能力,保障灌区泥沙长距离输运和持续运行的有效措施。     

基于灌区需水与水库兴利调度的水资源优化配置研究与应用

甘肃疏勒河灌区水资源优化决策支持系统通过对流域水资源特征、灌区需水量、水库调蓄功能以及生产力结构布局等矛盾的分析,建立了可持续发展水资源优化配置模型和多目标的目标函数、分解协调模型,可在不增减供、需水量的前提下提高水资源的配置效率,实现了节水、增产、保护生态的综合效益。     

生态脆弱地区适宜节水强度研究

选择宁夏青铜峡引黄灌区为研究对象,根据确保既不发生盐渍化也不发生荒漠化控制地下水埋深的原则,运用MODFLOW软件,构建了研究区的地下水数值模拟模型.采用情景分析方法,在模拟9种节水灌溉方案地下水埋深的生态适宜性基础上,给出了研究区适宜节水强度推荐方案.推荐方案对应的节水规模为全年引黄水量44.71亿m3,与2000年的60.29亿m3引水量相比,节水强度达到了25.8%,此为该灌区的适宜节水强度.     

Hydraulic bureaucracies and Irrigation Management Transfer in Uzbekistan: the case of Samarkand Province

Since the 1990s, Irrigation Management Transfer has been considered the world over to be a policy aimed at rolling back state influence in water management according to a neo-liberal approach. The initiative was endorsed by international organizations as a way of reforming the water sector in developing countries. Reflecting on this process, the role of hydraulic bureaucracies in driving reforms oriented towards IMT has often been neglected in academic debate. This article discusses the logic of IMT implementation and the establishment of Water Users' Associations (WUAs) in Uzbekistan, specifically in Samarkand province. These dynamics have been analysed over the last 10 years showing different trajectories within Uzbekistan. Data were collected through extensive fieldwork in three districts in Samarkand province. The evidence acquired shows that, on the one hand, WUAs were established to be a new structure for state control over water and agriculture, in conflict with IMT rationale, and, on the other, that WUAs were created in the province as a result of a local initiative promoted by the hydraulic bureaucracy and accepted by the national authorities due to influential power relations.     

Reducing Water Seepage with Anionic Polyacrylamide: Application Methods and Turbidity Effects

Researchers used column and flume experiments with uniform silica sand with and without suspended solids to examine the extent and longevity of hydraulic conductivity reduction (HCR) resulting from three anionic polyacrylamide (PAM) application methods, liquid injection, slurry surface, and granular surface application. Low turbidity (0.4 NTU) liquid injection column tests showed 20–65% HCR, likely caused by an extensional viscosity mechanism. HCR increased as turbidity increased, especially at low PAM concentrations. High turbidity (100 NTU) liquid injection column tests showed 66–77% HCR, likely through surficial PAM–clay aggregate filtration. Column and adsorption tests strongly suggest PAM–sand adsorption does not cause substantial HCR. In low turbidity flume tests, PAM slurry application to the sand surface produced up to 100% HCR, likely through a viscosity mechanism, and granular application to the media surface produced up to 100% HCR, likely through fixed surficial polymer gel formation. Hydraulic conductivity returned to control-adjusted pretreatment levels following PAM application in all tests except granular surface application at high mass loads or with high turbidity.