THE OPTIMAL DESIGN BASED ON RELIABILITY OF WATER DISTRIBUTION SYSTEM BY LINEAR MODEL

In this paper, a new technique are developed for optimal design of water distribution system besed on reliability. It applies a linear programming algorithm to the optimal design based on reliability. Within a small optimal search step range,the objective function and constraints can be expressed in the first order Taylor-expanding form,and three sub-models (a steady-state simulation model, a reliability model and a linear optimization model) are linked each in optimal searches. Thus, a traditional non linear problem can be solved by a linear model, the computing burden is significantly decreased. Therefore, the linear optimal model developed by the paper has more practical significance.     

CAPILLARY PRESSURE-SATURATION RELATIONSHIPS IN ROCK FRACTURE

Understanding and quantifying unsaturated flow through fractures in rocky slope is important for design and construction of drainage system in large-scale hydraulic engineering. The data of the hysteretic relationship between capillary pressure and water saturation are primary for simulating unsaturated flow in fractures and analyzing the stability of high rocky slope. The drainage and imbibition curves are measured for a single fracture in granite sample got at construction site of the Three Gorges Project (TGP). The method used in this study for measuring the capillary pressure-saturation relationship , under the conditions of no normal load to rock sample, is generally following the laboratory technique developed by Reitsma and Kueper. A distinct entry pressure, indicating rise to initiate nonwetting phase invasion, was observed. The drainage curve is found to be well represented by van Genuchten porous media capillary pressure function.     

TRANSIENT FLOW DRAINAGE EQUATIONS CONSIDERING BOTH DELAYED GRAVITY RESPONSE AND EVAPORATION FROM WATER TABLE

The drainable porosity is one of the important parameters in the unsteady drainage formulas. Due to delayed gravity response the drainable porosity is a function of the rate of drawdown and the depth of water table. The evaporation from groundwater plays an important role in lowering water table, in drainage design formulas it should be taken into account. Drainage equations considering evaporation from groundwater varying with water table depth and evaporation from water surface and involving constant drain-able porosity have been proposed by many authors. In this paper new formulas considering both delayed gravity yield and evaporation as a function of water table depth are developed and verified by experimental data.     

平面钢闸门主梁的可靠度分析及概率设计

概率设计法在工程设计各领域中已逐步得到应用，而作为水工建筑物重要组成部分的水工金属结构，目前的设计方法是按现行的设计规范－《水利水电工程钢闸门设计规范》的许用应力法进行设计的。因此，水工金属结构的设计准则向概率设计法过渡已是大势所趋。现以平面闸门主梁为研究对象，对水工金属结构的概率设计问题进行了研究，建立了主梁的设计表达式并确定了各分项系数值；探讨了水工金属结构概率设计的一般方法。     

黄河上游水文情报预报的发展与应用

黄河上游流域人烟稀少，经济不发达，６０年代前水文站网寥寥无几。７０、８０年代，黄委会上游水文水资源局，在该地区的黄河干流上恢复，新建了一批水文站，并在其主要支流设立了水文站。这些站网现控制站康乃亥以上流域的广大地区。     

三峡电站左厂1200t／125t桥机主梁挠度分析

安装于三峡电站左岸主厂房内的１２００/１２５ｔ桥式起重机,主要担负左岸电站１４台水轮发电机组及其辅助系统设备的安装、运行维护和检修的吊装任务。采用解析法对主梁进行了挠度计算,与试验数据进行比较并分析了计算结果,认为桥机主梁的主梁强度、刚度实时检测、监控系统基本上是可靠的,主梁２基本没有塑性变形。     

石羊河下游民勤水资源与生态环境治理对策

河西走廊石羊河下游———民勤地处我国干旱内陆区 ,民勤绿洲是我国典型的荒漠绿洲之一。由于石羊河水资源不合理开发利用 ,引起其下游民勤盆地的区域地下水位下降、水质恶化、土地沙漠化、盐渍化面积扩大 ,植被退化等一系列生态环境问题。文中对生态环境恶化产生的原因进行了分析 ,并就其生态环境保护与治理提出了对策。水资源问题是民勤生态环境问题的本质 ,要改善民勤的生态环境条件 ,首先必须解决好当地水资源问题     

邯郸市城市污水处理回用探索

重点介绍了邯郸市城市污水处理回用的情况,并对存在的问题进行了分析,对如何做好污水处理回用工作提出了具体措施和建议。     

人力资源管理视角下职业学校教师培训的几点思考

加强教师培训,是提高教师素质,实现职业教育全面、快速、均衡、和谐发展的需要。在国家大力发展职业教育、着力培养高技能人才的今天,职业学校教师培训工作的重要性凸显。笔者分析了职业学校教师培训的必要性,对教师培训存在的问题提出了一些想法,意在探讨提高职业学校教师培训的有效模式,强化职业学校人力资源管理。     

Selecting Agricultural Best Management Practices for Water Conservation and Quality Improvements Using Atanassov’s Intuitionistic Fuzzy Sets

Improper agricultural practices can affect ground water through leaching, surface water through runoff, algae infestations, deforestation, and air quality through burning operations and ammonia emissions. These effects may be mitigated through the institution of best management practices. The utility of best management practices (BMPs) is recognized and being actively promoted by agricultural agencies; however, identifying a set of mandatory BMPs is inappropriate given variations between climactic, demographic and geographic regions as well as differences in farming practices. In this study, a multi-criteria decision making model based on Attanassov’s Intuitionistic Fuzzy Set (A-IFS) theory is introduced and its utility to rank agricultural best management practices is illustrated using a case-study from South Texas. Implementation of the A-IFS MCDM method to the South Texas region resulted in “irrigation scheduling” being ranked as the most preferred alternative, while “brush control/management” was the least preferred. The A-IFS MCDM approach was particularly suitable for prioritizing and ranking agricultural best management practices because decision makers often tend to have both likes and dislikes with regards to specific BMPs and for a given evaluation attribute. Not only does the A-IFS MCDM method provide a single composite score to rank the BMP alternatives, but the output of the A-IFS MCDM method also includes upper and lower bounds that help identify the uncertainties in the decision making process.