Inclusion of Ecological Water Requirements in Optimization of Water Resource Allocation Under Changing Climatic Conditions

Water Resources Management - Meeting ecological water requirements (EWRs) is important for maintaining watershed system stability in many arid and semi-arid areas. Rainfall–runoff...     

不同地下水埋深条件下农田潜水蒸发规律

汾河灌区作为山西省最大的自流灌区,近年来引用水量不足导致用水供需矛盾突出,文中分析了汾河灌区不同地下水埋深条件下农田潜水蒸发的规律,对今后灌区控制盐碱化的发生起到了重要的作用.     

模拟降雨条件下垄膜方式对土壤蓄水效应影响

通过小区试验和模拟降雨的方法,分析了旱作区不同降雨量下不同垄膜覆盖方式对土壤水蓄积效应的影响。结果表明:随着模拟降雨量增大,0～50 cm土层的土壤贮水量及其增量增大,表现为垄作全覆膜(QLM)垄作半覆膜(BLM)传统平作(CKM)。对于沙壤土,垄作全覆膜较传统平作贮水量增量增大0.9～3.4 mm,产流效率为10.50%～27.50%,蓄墒增加率为36.21%～95.65%;垄作半覆膜较传统平作贮水量增量增大0.6～2.1 mm,产流效率为5.00%～15.00%,蓄墒增加率为17.24%～55.26%。对于壤土,垄作全覆膜较传统平作贮水量增量增大1.7～6.8 mm,产流效率为31.00%～45.83%,蓄墒增加率为75.68%～95.77%;垄作半覆膜较传统平作贮水量增量增大1.4～4.2 mm,产流效率为15.00%～35.00%,蓄墒增加率为75.68%～95.77%。试验验证了不同覆膜方式的集雨效果、土壤蓄水和保墒效应,全覆膜和半覆膜垄上沟播模式能够起到集雨增温保墒作用,可提高土壤蓄水,实现区域降水资源的高效利用。     

变化条件下干旱内陆河流域水循环特征研究

为探索干旱内陆河流域降水稀少、生态环境脆弱、人类长期活动和剧烈气候变化等对流域内水循环产生的影响,以玛纳斯河流域为例,根据天然-人工二元水循环系统理论,建立了二元水循环模型,并对该流域水循环每一环节的蒸发、渗漏进行了计算.结果表明:玛纳斯河流域平原区天然水循环通量为9.38亿m3/a,占流域降水通量的11.70％;人工水循环通量为18.35亿m3/a,占流域降水通量的22.88％;平原区的人工水循环通量已经远远超过了天然水循环通量.玛纳斯河流域总水循环通量为80.26亿m3/a,现状条件下全流域天然水循环通量为61.91亿m3/a,流域天然水循环通量与人工水循环通量的比例为77.14∶22.86.     

水深与卵石粒径同量级下的河道糙率分析

通过水槽试验,探讨了卵石河道糙率在水深与卵石粒径同量级情况下随不同比降、流量的变化规律.结果表明:对于同一卵石河床,糙率不为常数,糙率随着水深和断面平均流速的增大而减小,当h/d＞2.5时糙率趋于定值;当h/d＜2.5时,糙率随着水深和断面平均流速的减小而增大.     

泵站加压条件下规模化灌溉管网优化方法研究

规模化灌溉管网中管线较长、出流口多,各个出流口易出现压力不均衡问题。结合树状灌溉管网的特点与最优化原理,以管网综合费用为目标函数、出流口压力均衡为主要约束条件,建立了泵站加压状态下的规模化管道输水灌溉管网的优化模型,采用LINGO对优化模型求解,得出了在管道投资最少和压力均衡条件下的最优管径组合方案。优化算例表明:此优化模型相比经济流速法设计的管网,总费用降低4.1%;管网内各个出流口压差不超过20%,满足管道输水灌溉设计中对水压的要求,能够使管网出流口压力均衡。     

有冰盖条件下平板闸的输水能力研究

高纬度地区的河流在冬季常会形成冰盖、冰塞或冰坝,水流从明流变为封闭的暗流,水流的水力条件、热力条件和几何边界条件发生改变,出现冬季特有的冰情现象。采用人工模拟的冰盖进行试验,分析冰盖的淹没程度以及冰盖前缘与闸门的距离变化时闸门出口流量系数的变化情况。结果表明:出口流量系数随着冰盖淹没程度的增大而减小,随着冰盖前缘与闸门之间距离的增加而增大。     

不同条件下WES堰下泄水流水噪声试验研究

通过对不同的消力池尾坎高度、不同的消力池长度、不同流量下WES堰下泄水流水噪声进行测量,研究WES堰下泄水流与上游来水流量及下游消力池状况的关系。结果表明:在流量、消力池长度均相同的条件下,尾坎高度的改变会影响WES堰下泄水流声压大小,随尾坎高度提高,水声压降低;在上游来水流量、消力池尾坎高度相同时,WES堰下泄水流声压随着消力池长度的增长而下降;在相同消力池长度和尾坎高度情况下,WES堰下泄水流声压随流量的增大而总体上升。     

Applicability of Adapted Reservoir Operation for Water Stress Mitigation Under Dry Year Conditions

This paper introduces the conjunctive use of a deterministic water quality model and water balance criteria for supporting the assessment of simulation and to evaluate the effectiveness of proposed operation strategies. By this, the applicability of enhanced reservoir operation strategies addressing both water quality as well as water quantity aspects under water deficit conditions in dry years can be shown. Arguments will be developed to address stakeholders and decision makers in the context of a more conservative past operation regime. Results are presented for the Kaparas reservoir, which is located in the lower Amu Darya River, on the border of Turkmenistan and Uzbekistan. As being one out of four large reservoirs of the Tuyamuyun Hydro Complex (THC), the Kaparas reservoir could be increasingly used for drinking water supply for the lower Amu Darya region. The results for the dry year 2001 indicates that the combination of simulation together with practical assessment criteria confirm the applicability of adapted operation rules for THC reservoirs and ways can be found to supply the local population (of the lower Amu Darya region) with more potable water of higher quality even subject to a parallel reduction of water deficits. Future aggravation of water stress due to increasing population growth and water quality deterioration will require a more comprehensive consideration of water quality aspects in many arid and semi arid regions. The experience gained during this study emphasizes the fact that classical deterministic water quality models provide effective tools to address even more complex water quality problems under water stressed conditions, provided processing of results is performed, to support the decision making process.     

Regional Water Use Structure Optimization Under Multiple Uncertainties Based on Water Resources Vulnerability Analysis

In this paper, a modeling framework by combining system dynamic (SD) model and optimal allocation model was developed to study water resources vulnerability and optimal water use structure, and the framework was applied in the middle reaches of Heihe River basin, northwest of China. The SD model could describe the dynamical change of water resources vulnerability by integrating water resources with socio-economic effect. The sensitivity analysis of SD model was then conducted to design appropriate scenarios for finding out the optimal development pattern, and based on which, an integrated water-saving scenario with lower water resources vulnerability was identified for optimization modeling. Then, an inexact fuzzy-parameter two-stage programming (IFTSP) model was developed and applied to optimize water use structure among industries under uncertainties. This study addresses the water resources vulnerability analysis in considering both water resources system and socio-economic system. Water resources vulnerability analysis was combined with optimization model to make adaptive water resources management plans. And the optimal allocation schemes under lower water resources vulnerability are more advantageous for regional sustainable development.     

不同含沙量不同流速下水轮机磨蚀性能研究

为了更加科学地防治和减轻水轮机泥沙磨蚀危害,对其磨蚀特性进行了研究.采用黄河原型沙配制含沙水流,对1Cr18 Ni9Ti、ZGOCr16Ni5Mo材质的水轮机过流部件进行磨蚀试验.结果表明:当含沙量相同时,过流部件材料的磨蚀失重量随着流速的增大而增大;当流速相同时,磨蚀失重量随着流体含沙量的增大而增大;在试验含沙量10～100 kg/m3范围内,过流部件材料的磨蚀失重率随流速的增大而增大,磨蚀失重率与流速呈幂函数关系.     

Adjustable Robust Optimization for Multi-Period Water Allocation in Droughts Under Uncertainty

Optimal water resource allocation can go some way to overcoming water deficiencies; however, its achievement is complex due to conflicting hierarchies and uncertainties, such as water availability (WA) and water demand (WD). This study develops a robust water withdrawal scheme for drought regions that can balance the trade-offs between the sub-areas and water use participants, ensure sustainable regional system development, and guarantee robust solutions for future uncertainties. A bi-level affinely adjustable robust counterpart (AARC) programming framework was developed in which the regional authority as the leader allocates water to the sub-areas to maximize the intra- and intergenerational equity, and the sub-areas as the followers allocate water to their respective water departments to maximize their economic benefits and minimize water shortages. A case study from Neijiang, China, is given to illustrate the applicability and feasibility of this framework. The novelty of this study is to propose a sustainable bi-level AARC regional water allocation framework which integrates intra- and inter-generational equity of regional water use and priority rules reflected by goal preference programming between water departments under uncertainties of WA and WD simultaneously in water deficient regions.

     

地下水埋深对玉米生长及地下水补给的影响

为研究地下水埋深对玉米生长发育及作物系数的影响,选择宁夏彭阳县红河镇玉米为研究对象,借助试坑模拟对比试验,通过试坑旁的马氏瓶控制地下水位,探讨了地下水埋深对玉米生育期株高、干物质积累量、土壤含水率、产量、地下水补给量和作物系数的影响。结果表明:地下水埋深对玉米生长指标影响显著,地下水埋深为0.9 m时地下水补给量最大为83.5 mm,地下水埋深为1.2 m时地下水补给量最小为54.7 mm。     

Optimal Hydropower Generation Under Climate Change Conditions for a Northern Water Resources System

This paper examines climate change impacts on the water resources system of the Manicouagan River (Québec, Canada). The objective is to evaluate the performance of existing infrastructures under future climate projections and the associated uncertainties. The main purpose of the water resources system is hydropower production. A reservoir optimization algorithm, Sampling Stochastic Dynamic Programming (SSDP), was used to derive weekly operating decisions for the existing system subject to reservoir inflows reflecting future climate, for optimum hydropower production. These projections are simulations from the SWAT hydrologic model for climate change scenarios for the period from 2010 to 2099. Results show that the climate change will alter the hydrological regime of the study area: earlier timing of the spring flood, reduced spring peak flow, and increased annual inflows volume in the future compared to the historical climate. The SSDP optimization algorithm adapted the operating policy to the future hydrological regime by adjusting water reservoir levels in the winter and spring, and increasing the release through turbines, which in the end increased power generation. However, there could be more unproductive spills for some power plants, which would decrease the overall efficiency of the existing water resources system.     

水上光伏电站新模式下不同材料节水效益研究

为了有效结合光伏发电技术与防蒸发节水技术,选出一种综合效益更高的防蒸发材料,以节水效益为切入点,以干旱区水上光伏电站新模式最小单元体为研究对象,利用苯板、PVC浮板以及PE浮球作为防蒸发材料,对新模式节水效益进行研究,并进行投资回收期分析.结果表明:按照干旱区水上光伏电站新模式结构形式布置,在水面覆盖1 m2苯板、PV...     

电网限流措施的优化配置

提出一种电力系统限流措施的自动优化配置方法,即采用0-1变量模拟各种限流措施的投运与否,采用普通整数变量模拟限流电抗器、故障限流器（FCL）以及高阻抗变压器的容量,形成一个混合整数规划问题,并用分支定界法等求解。用IEEE 9节点系统和中国西部某地区电网19节点系统进行了仿真计算,验证了所提出的方法的可行性。     

Sustainability of Small Reservoirs and Large Scale Water Availability Under Current Conditions and Climate Change

Semi-arid river basins often rely on reservoirs for water supply. Small reservoirs may impact on large-scale water availability both by enhancing availability in a distributed sense and by subtracting water for large downstream user communities, e.g. served by large reservoirs. Both of these impacts of small reservoirs are subject to climate change. Using a case-study on North-East Brazil, this paper shows that climate change impacts on water availability may be severe, and impacts on distributed water availability from small reservoirs may exceed impacts on centralised water availability from large reservoirs. Next, the paper shows that the effect of small reservoirs on water availability from large reservoirs may be significant, and increase both in relative and absolute sense under unfavourable climate change.     

自由临界水跃跃后水深的探讨

自由临界水跃的跃后水深对设计消能防冲工程的安全和经济性起着很重要的作用 .为解决跃后水深的准确计算问题 ,推求出应用范围较大的跃后水深计算公式 ,并举例进行分析计算 .结果表明 ,文中公式可以满足消力池和冲刷坑水力计算的需要 .     

Environmental and Resource Costs Under Water Scarcity Conditions: An Estimation in the Context of the European Water Framework Directive

The European Water Framework Directive (WFD) requires the good ecological status of surface water bodies, which implies the improvement of both their physicochemical condition, as well as their flow and continuity. The WFD prescribes the assessment of environmental and resource costs and benefits associated with implementing these improvements. The recent literature focuses almost exclusively on the assessment of the economic values related to quality aspects. However, in much of southern Europe, fulfilling the WFD goals will greatly depend on maintaining sufficient water flow, as well. This study aims to fill this gap by assessing the non-market value of allocating enough water to the environment to ensure environmental services are sustained when water is scarce. The non-market value of guaranteeing water supply for secondary household uses is also estimated. Using the Guadalquivir River Basin in Spain as a case study, a choice experiment is applied with scenarios characterized by varying water flow levels and accompanying environmental impacts, and a different frequency of household water restrictions. The results show that the population derives significant benefits not only from the direct use of water, but that also holds non-use values related to the ecological status, although the latter has a considerably lower impact on consumer surplus. Additionally, we conclude that the costs of implementing the water saving measures currently included in the Program of Measures seem to be proportionate to its benefits in this case.