华东区域市场月度购电决策模型实证比较

华东区域电力市场中，电力公司在月度市场中报价，日前市场中只申报负荷需求，以管制价格对用户售电。各个市场中竞价电量的分配以及报价直接影响到电力公司的收益和市场稳定。文中基于投资组合理论，对电力公司考虑风险的月度购电策略进行了研究。首先对3种风险计量指标的购电决策模型从实际应用角度进行了分析，其中基于半方差的购电模型为首次提出;其次针对购电侧分段报价规则，提出了利用分段降低风险的月度分段报价模型;最后结合实际数据对各种模型进行了实证分析。     

电力市场下的发电机组状态检修

分析了目前制定检修计划中片面强调电力市场因素或机组状态因素都会严重影响检修效益，以及在电力市场下进行发电机组状态检修的可行性，然后提出了一种基于电力市场的发电机组状态检修数学模型，该模型引入了不检修的费用损失的概念，以检修或不检修的平均费用损失（费用损失/检修周期）最小为目标函数，根据最小值来确定在合约期间是否需要检修以及如果需要时的检修时间。仿真算例表明，该模型有效地协调了电力市场和机组状态的关系，给发电厂带来了最大的检修效益。     

新型区域电力系统电源规划和时序生产模拟

以新能源为主体的新型区域电力系统电源规划和时序生产模拟面临较大困难,针对于此,设计了区域电力系统机组检修计划与机组组合的双层耦合框架,提出了中等规模机组集群方法,可使机组检修与机组组合优化直接耦合。还提出了新型区域电力系统检修优化模型,以系统空闲容量最小为目标函数,考虑系统电力平衡、调峰容量平衡等约束条件,检修计划有利于促进新能源消纳。在机组组合优化模型中,以系统运行成本最小为目标函数,对中等规模火电机组集群进一步采用机组集群求解方法,较准确计算火电运行及机组启停煤耗。在区域电力系统时序生产模拟中,上述方法计算结果明显优于启发式方法,可对各类电源间出力协调平衡进行全局寻优。     

考虑预期利润目标的发电商多交易市场发电量分配策略

在竞争的电力市场环境中，各个交易市场不同的价格波动性带来不同的利润和风险，发电商需要在各市场中合理分配有限的发电量，以在利润和风险之间进行协调，使其自身效用最大化。目前，已有决策方法一般借鉴现代投资组合理论中的均值方差模型,然而，该模型关于发电商风险偏好始终一致的假设并不符合一般决策心理。为此，文中使用价值函数描述了发电商对利润分布形式变化的风险偏好，并计及了达到预期利润目标概率对分配决策的影响，从而使得市场分配结果更加符合发电商的心理愿望。此外，还在计算分配方案的利润分布过程中考虑了最低报价对风险的规避作用，使得决策结果更加准确。最后，算例分析验证了文中方法的有效性。     

日前市场下发电商机组优化组合研究

日前电力市场下,发电集团经常面临在给定总负荷出力曲线和总备用服务要求下,如何在机组间(厂间)进行合理分配出力/备用容量的优化问题,针对于此,提出了考虑旋转备用服务的日前市场机组组合模型和"基于决策树的动态规划法"的求解方法,并利用该方法进行了具体实例计算,深入分析了旋转备用被调用概率、结算价格和容量对机组组合模型优化结果的影响,为发电集团合理安排日前市场下机组间(厂间)负荷分配或联合调度营运提供了一定的思路和实际意义。     

分段竞价在区域电力市场中的应用方案

结合分段竞价的基本规则和原理模型,对分段竞价在区域电力市场中的应用难点进行了研究。在优先安排水电后,讨论了修正后负荷曲线划分容量段的实用方法;针对区域电网需要根据各省差异而划分价区的实际情况,在竞价出清过程中引入了省间潮流断面约束,从而实现了自动划分价区;在竞标选择和约束下调时,结合机组最小技术出力和省间潮流断面输送容量约束,采用按比例的方法分配报价相同机组的容量。考虑了负荷容量平衡、机组出力、省间潮流断面等约束,建立了区域电力市场分段竞价数学模型。结合以上实用化处理方法,该模型可以采用排队算法求解。对包含87台火电机组的实际系统进行仿真计算,验证了该方法的有效性。计算结果显示区域电力市场采用分段竞价方式,对电网公司和发电公司都是较好的方案。     

合同交易量和竞价交易量在日计划中的经济分配

目前电网公司在进行现货交易时，一方面要依据各发电公司申报的上网电价，另一方面也要考虑与发电公司原有的购售电合同，因此如何在保证完成年购售电合同的前提下，在机组竞价上网电价一定的条件下，使总的购电费用最低？基于这个目的，文中建立了在交易日的96个交易时段经济分配日合同交易量和竞价交易量的数学模型，并应用线性规划法对该模型进行求解；文中给出的协调上网机组在各交易时段的合同交易量和竞价交易量的具体办法，在一定程度上限制了机组利用其特性约束条件进行投机报价；根据机组合同交易量的完成情况，滚动修正其下一交易日的日合同交易量，并给出表征机组上网紧迫程度的指标。该模型和算法已经在我国某省电力市场现货交易中得到有效的应用。     

计及发电机报价和负荷消费意愿的可用输电能力计算

提出一种在电力市场环境下考虑经济性约束的区域间可用输电能力的计算方法，建立了在系统每一运行点都能根据发电机组报价经济地分配其有功出力并限制各节点电价在某一可行范围内的数学模型，其目标函数是购电区域内负荷的增长量最大，约束条件为系统的安全性约束和经济性约束，更符合电力市场的实际情况。采用主从递阶决策求解数学模型，并利用非线性互补问题函数的近似半光滑牛顿算法处理底层优化问题所带来的不等式约束。以IEEE 30节点系统为例进行仿真并对计算结果予以分析，验证了所提出的方法的合理性。     

考虑网损和输电约束的发电竞价交易方法

采用非线性规划方法解决电力市场中机组多时段报价与发电计划问题。建立了考虑抽水蓄能电站的多时段发电计划模型，在排序的基础上考虑输电约束和网损对发电计划的影响，用非线性优化方法进行计算，得到满足报价和电网约束的最优发电计划。对一个6节点母线系统进行了多时段发电交易计划分析，结果显示电网输电约束和传输损失对发电计划产生影响，多时段发电计划优化能带来更大的全局经济利益。     

发电机组检修市场的初步设计

电力市场环境下调度部门如何在保证系统可靠性的同时保证调度的公平性，这是一个亟待解决的问题。设计了一种新的发电机组检修计划制定模型：首先由各发电公司根据机组的检修周期、运行情况、对未来电价水平的预测和调度部门公布的未来各时段的最大检修容量，在规定的时间内上报机组的检修起始时间、检修持续时间、检修容量和检修报价；然后调度部门根据各发电公司的报价，对能够满足系统可靠性要求的检修机组按照报价从高到低的顺序安排检修，并收取相应的费用，而其余检修机组则按照等备用原则进行安排；最后调度部门将所收取的费用按照类似并联电路电流分配原则返还给各发电公司，从而确保其非盈利性。文中所提出的模型，既充分体现了发电公司的检修自主权，又保证了系统的安全可靠和调度的公平性。     

SPATIAL AND TEMPORAL WATER QUALITY VARIABILITY IN AQUATIC HABITATS OF A CULTIVATED FLOODPLAIN

The floodplains of lowland rivers contain diverse aquatic habitats that provide valuable ecosystem services but are perturbed when intensively cultivated. Hydrologic, water chemistry and biological (fish) conditions in five aquatic habitats along the Coldwater River, Mississippi, were measured for more than 4 years: the river, two severed meanders that functioned as backwaters, a managed wetland and an ephemeral channel draining cultivated fields. Off‐channel habitats were connected to downstream regions 0.10% to 32% of the dry season and 24% to 67% of the wet season. The median temperatures for the five monitored sites ranged from 18°C to 23°C, the median total solids concentration for all sites was 135 mg L^?1, the median total phosphorus was 0.29 mg L^?1 and the median total nitrogen was 1.56 mg L^?1. Chemical and physical water quality displayed strong seasonal differences between the wet winter/spring and the dry summer/fall periods so that temporal variation consisted of gradual seasonal trends superimposed on strong diurnal variations. All off‐channel habitats exhibited periods of hypoxia and temperatures >30°C during the dry season. Between‐site gradients of water and habitat quality were strongly coupled to water depth and runoff loading. The rehabilitation of one backwater by increasing water depth and diverting agricultural runoff was associated with improved water quality and fish species richness relative to an adjacent untreated backwater. The diversion of polluted runoff and the use of water control structures to maintain greater water depth were observed to be effective management tools, but the former reduces the water supply to habitats that tend to dry up and the latter reduces connectivity. Published in 2011 by John Wiley & Sons, Ltd.     

Spatio‐temporal variation of gross CO2 and CH4 diffusive emissions from Australian reservoirs and natural aquatic ecosystems,and estimation of net reservoir emissions

Carbon dioxide (CO₂) and methane (CH₄) diffusive emissions were measured during two field surveys in Queensland and Tasmania, Australia, using the floating chamber method. Bubbling and degassing emissions in 2010 were estimated in Koombooloomba Dam reservoir using only inverted funnels and gas concentrations, respectively. A total of 14 reservoirs and 16 rivers and lakes were sampled from 2006 to 2010. Spatial variation was substantial within each water body, as well as between them. The main drivers of diffusive emission variation were physiographic region and climate, with a clear demarcation being observed between diffusive emissions from tropical Queensland and temperate Tasmania, and between the humid West Coast Range (Tasmania) and dry Central Plateau (Tasmania). Higher CO₂ and CH₄ diffusive emissions were observed during the dry season, when long water residence times would promote organic matter degradation. Estimated total gross emissions, including diffusive, bubbling and degassing emissions, for Koombooloomba Dam reservoir were about 1.5 × 10⁶ t CO₂eq km² per year, or 24 × 10⁶ t CO₂eq per year. This corresponds to a plant emission factor of 3.18 kg CO₂eq MWh^?1. Using an estimate of terrestrial emissions derived from literature data for the Tully River catchment area, rough estimated net emissions from the catchment area are about 44 kt CO₂eq per year, or 5.83 kg CO₂eq MWh^?1, which is in the lower range of the studied reservoirs.     

Call for Papers

正As the eldest and most distributed professional journal of water industry,Water Wastewater Engineering(W WE)gained very wide acceptance from the colleagues working in this field in this country since start publication in 1964.Now it is administrated by the Ministry of Construction of the People’s Republic of China and sponsored by the China Civil Engineering Society etc.     

Serial discontinuities in a Rocky mountain river. II. Distribution and abundance of trichoptera

River regulation in the headwaters and middle reaches of the Gunnison River, Colorado, significantly altered distributions and abundances of Trichoptera fauna. Twenty-five species were collected from mainstream samples, with the greatest species richness occurring at an unregulated, rhithron segment above the central reach dams. At sites immediately below the three hypolimnial-release dams and a reregulation dam, species richness was reduced 35–90 per cent and abundance > 95 per cent. Net-spinning caddisflies were the dominant trichopterans at unregulated sites; Arctopsyche grandis in the upper reaches (218 organisms, 586 mg dry mass m^?2) and Hydropsyche cockerelli, H. occidentalis and Cheumatopsyche pettiti in the lower river (9041 total organisms, 6621 mg m^?2), downstream from the last dam. The observed distributional pattern of low trichopteran densities in dam tailwaters and high hydropsychid densities at sites 60–80 km below the central reach dams is a classic expression of continuum resets and adjustments in response to stream regulation as predicted by the Serial Discontinuity Concept.     

Surveying for Water Resources

Abstract

A professional Land Surveyor (Geomatician) describes the Hydrogeologists' survey requirements of a major water resources assessment for the government of The Sultanate of Oman (1992 to 1996). The need for objective specifications is stated. Specialist terms like geoid, spheroid, Mean Sea Level are explained and how to relate spheroidal levels to the geoid. Methods like traditional survey, satellite survey, and photogrammetry are introduced. The paper encourages coordinated working for the benefit of water resource assessment and recommends employment of the professional land surveyor for major studies.     

库水波动下库岸边坡地下水浸润线解析解及误差分析

解析法是库岸边坡地下水浸润线计算中便于实际应用的方法,但该方法须基于若干假定并对潜水运动基本方程线性化后才能求解。针对各假定和线性化过程建立不同的地下水渗流数学模型,用解析法和有限元法解答上述数学模型,分析各误差大小及其规律。结果表明：库岸垂直处理带来的误差要小于方程线性化处理和不考虑非饱和渗流带来的误差,而且它们都随渗透系数变大而减小;在三峡库区库水调度情况下,假定库水位等速变化带来的误差对大多岸坡而言可以忽略;计算库岸边坡地下水浸润线时,解析法只适用于水位变化幅度相比含水层厚度较小,且几何边界规则、岩土结构简单、岩土体渗透性较好时的情况。     

Changes in Summer Irrigated Crop Area and Water Use in Southeastern Turkey from 1993 to 2002: Implications for Current and Future Water Resources

Changes in summer irrigated cropland acreage and related water use are estimated from satellite remote sensing and ancillary data in semi-arid Southeastern Turkey where traditionally dry agricultural lands are being rapidly transformed into irrigated fields with the help of water from the Euphrates-Tigris Rivers. An image classification methodology based on thresholding of Landsat NDVI images from the peak summer period reveals that the total area of summer irrigated crops has increased three-fold (from 35,000 ha to over 100,000) in the Harran Plain between 1993 and 2002. Coupled analysis of annual irrigated crop area from remote sensing and potential evapotranspiration based estimates of irrigation water requirements for cotton indicate a corresponding increase in agricultural water use from about 370 million cubic meters to over one billion cubic meters, a volume in accordance with the state estimates. These estimates have important implications for understanding the rapid changes in current agricultural withdrawals in Southeastern Turkey and form a quantitative basis for exploring the changes in future water demands in the region. For example, expansion of irrigated lands have led to a steady decrease in potential evaporation due to increased roughness and decreased humidity deficit in the Harran Plain. Assuming that the changes in future evaporation conditions will be of similar nature, water use for irrigation is expected to decrease over 40 percent in future irrigation sites. Incorporating this decrease in overall planning of the irrigation projects currently under construction should lead to improved management, and by extension, sustainability of water resources in the region.     

The Impact of Economic Development on Water Pollution: Trends and Policy Actions in Malaysia

The paper examines the impact of development activities on water pollution in Malaysia. Hence, the main objective of this paper is not just to examine the trends of development-induced water pollution around the region of the country but to know where the problems are and the policy measures taken by the government. It evaluates the probable causative relationship between problems introduced due to technology employed in water pollution control and governmental policy measures. It examines the relationship between development indicators as sources of pollution and polluted rivers over a period of 12 years. The findings of the paper have shown that despite the policy enforcement actions against the identified sources of water pollution, all the three development indicators (chosen based on those identified sources) still accounted for high percentage of river pollution in Malaysia. The findings of the paper were used to identify the central fact of the location of the problem. Some crucial conclusions of where the problems likely to be, as reflected in the findings, are: (a) the issue of interactive-effects between pollutants that many policy-makers are not aware of. This is when policy measures concentrate only on one source of water pollution; (b) the enforcement strength and/or effectiveness of policy measures themselves; (c) financial constraints to invest in appropriate technology especially sewerage systems for controlling human source of water pollution in the country; as well as those confronting small polluting industries (d) finally, lack of cooperation between government and private business firms to comply with regulatory policies for water pollution control.     

浅淡溢洪道改扩建方案与选择

溢洪道改扩建和进行溢洪道方案布置，要择优选取溢洪道进口型式、防冲消能工，以使其工程量省、施工快、运行管理方便     

Intangible Flood Damage Quantification

Flooding is a natural disaster that may cause tremendous tangibleand intangible damage to the national economy. The tangible damage assessment, i.e. the monetary value of all direct and indirect physical damages, has already been studied, whileintangible damages have not yet been taken into account. Thisarticle, therefore, is the first systematic attempt to assess bothtangible and intangible damages. The new proposed Anxiety-Productivity and Income Interrelationgship Approach (API) has been developed to quantify the intangible damage in monetary terms. The Bangkok area has been selected as the research area because several severe flood events have occurredthere over the last two decades. The 1983 Bangkok flood caused 6600 million baht in damage, according to estimates by the National Statistical Office (NSO). This article examines the totalflood damage (including the intangible damage) at different flood magnitudes. Case studies with and without flood mitigation projects are studied and compared. Furthermore, thisarticle also discusses the improvements over the conventional approach offered by the new API methodology.