滦河流域水资源可持续利用对策分析

随着人口增长和经济社会的快速发展,对资源需求量急剧增加,水资源短缺已成为严重制约滦河流域经济发展的重要因素。文中简要分析了滦河水资源开发利用中存在的问题,并从提高水的利用效率、调整产业结构、加强水利工程建设、完善水资源管理体系等方面提出了实现水资源可持续利用的对策。     

Parameter Sensitivity and Predictive Uncertainty in a New Water Quality Model, Q2

A new dynamic model of water quality, Q2, has recently been developed, capable of simulating large branched river systems. This paper describes the application of a generalized sensitivity analysis (GSA) to Q2 for single reaches of the River Thames in southern England. Focusing on the simulation of dissolved oxygen (DO) (since this may be regarded as a proxy for the overall health of a river); the GSA is used to identify key parameters controlling model behavior and provide a probabilistic procedure for model calibration. It is shown that, in the River Thames at least, it is more important to obtain high quality forcing functions than to obtain improved parameter estimates once approximate values have been estimated. Furthermore, there is a need to ensure reasonable simulation of a range of water quality determinands, since a focus only on DO increases predictive uncertainty in the DO simulations. The Q2 model has been applied here to the River Thames, but it has a broad utility for evaluating other systems in Europe and around the world.     

城市排污系统对河流水质影响的仿真研究

以城市废水系统的集成化管理为出发点，基于国际水协会河流水质1号模型(RWOMI)，确定了适合仿真与实时控制的简化的动态河流水质模型，在MATLAB仿真环境下建立了一个以河流为核心的集成化城市废水系统的简单仿真环境。以某河流城区段为背景，采用国际水协会发布的污水负荷和组分数据作为原始输入，模拟了排水管网和污水处理厂在不同运行条件下引起的河流水质的变化情况。仿真结果表明排水管网组合下水溢流和污水处理厂排放物的处理程度对河流水质会产生直接影响，为集成化管理提供了依据。     

Non-point source critical area analysis in the Gisselö watershed using GIS

In the southeast in Norrköping, Sweden, is a small fjord-like bay called Slätbaken. The water quality in Slätbaken—with its narrow outlet to the Baltic Sea—depends highly on the water quality of the streams that flow in it. While point pollution sources can be identified easily in general, the non-point sources are harder to find. The most important sources for non-point pollution are agricultural areas, and the pollutants are mostly nutrients like phosphorus, which come from the fertilisation of the fields. One important catchment area for Slätbaken is the 57.7 km² Gisselö river basin (part of the topographic map 8GNO), which contains large agricultural areas.The transport of water pollutants is based on the same hydrological processes as erosion and sediment transport. The implementation of such a model in a GIS allows the analysis of a large area with a high resolution. When choosing the model, special attention was paid to the possibility of using a verified model that is easy to implement in a commercial GIS without the need of too much expert knowledge. This may allow its widespread use in many administrative applications that need non-point source information. A feasibility test for an enhanced GIS USLE model was done in the Gisselö drainage basin before it was implemented for all river basins in the whole administrative area of Norrköpings kommun.It is possible to use the suggested simplified USLE model to estimate the load of both pollutants and sediments, and it is able to show the areas that are critical for the water quality at the outlet of the water basin. The model has been evaluated in three studies [Int. J. Geogr. Inf. Syst. 2 (4) (1988) 365; A GIS to target critical areas for non point source management, in: Proceedings of the International Non Point Source Management Symposium, Austin, TX, November 7, 1989; Vatten 48 (1992) 117]. Then, implemented in a very simple GIS that allowed only rough estimates of terrain models and distances, the model was able to estimate the total suspended solids (TSS) and total phosphorus (TP) loads in the Svartå river basin of 1539 km² in the same region as Gisselö and the Bornsjö river basin outside Stockholm. Besides an estimated R² of 0.91–0.98 (verified by a more than one year measurement from manual and automated sampling stations in the whole river basin), the benefit with the GIS implemented USLE was the possibility to identify the risk areas with high spatial accuracy. During the last decade, both available databases and software have changed the possibilities to identify areas at risk of nutrient leakage. Schein [GIS Methods for Monitoring Sustainable Development by Analysis of Land-use and Land Cover Changes in the Surroundings of Linköping (Sweden), Institut für Photogrammetrie und Fernerkundung, Technische Universität Dresden, Germany] and Schein and Sivertun [Method and models for sustainable development monitoring and analyses in GIS, in: Proceedings of the International Workshop on Geo-Spatial Knowledge Processing for Natural Resource Management, University of Insubria, Varese, Italy, June 28–29, 2001] show that the enhanced land use data available through the European Union agricultural support program can be used together with remote sensing data to fine tune the modified GIS USLE model. The problems with the new 50×50 m digital elevation data now available are also pointed out here. Obvious errors in the data and possibilities to enhance the model by introducing a better terrain model were two important suggestions in these works. In this article, two modifications to the original model are suggested. One is enhancement of the digital terrain model by using height curves from the digital 1:50 000 scale topographic map, and the other is a smooth distance function that better reflects the impact of nutrients on water bodies.Because of its easy implementation on standard low cost systems, the GIS USLE model is suitable for analysing huge areas for critical places. The results can lead to more detailed studies in the risk areas thus identified or to investigations on the effect of land use changes, or can be used simply for taking care in the use of fertilisers and other chemicals in the critical agricultural areas.     

Bio-optical properties in waters influenced by the Mississippi River during low flow conditions

Spatial and temporal patterns of bio-optical properties were studied in the Northern Gulf of Mexico during cruises in April and October of 2000, a year during which the discharge volume from the Mississippi River was unusually low. Highly variable surface Chl a concentrations (0.1 to 17 mg m⁻³) and colored dissolved organic matter (CDOM) absorption (0.07 to 1.1 m⁻¹ at 412 nm) were observed in the study region that generally decreased with increasing salinity waters, being highest nearshore and decreasing at offshore stations. The optical properties of absorption, scattering, and diffuse attenuation coefficients reflected these distributions with phytoplankton particles and CDOM contributing to most of the spatial, vertical, and seasonal variability. The diffuse attenuation coefficient K_d(λ) and spectral remote sensing reflectance R_rs(λ) were linear functions of absorption and backscattering coefficients a(λ) and b_b(λ) through the downward average cosine μ_d and the ratio of variables f/Q at the SeaWiFS wavebands for waters with widely varying bio-optical conditions. Although various R_rs(λ) ratio combinations showed high correlation with surface Chl a concentrations and CDOM absorption at 412 nm, power law equations derived using the R_rs(490)/R_rs(555) and R_rs(510)/R_rs(555) ratios provided the best retrievals of Chl a concentrations and CDOM absorption from SeaWiFS reflectance data.     

浅谈水闸沉井基础施工技术

在钱塘江沿岸水利工程建设中，采用沉井基础，迄今有30多年的历史，作者从长期的施工实践中，摸索了一些经验与体会，主要介绍水闸的单井沉放和多井间隔沉放的沉井基础施工技术。     

黄河冲淤特性"相对清水冲刷、相对浑水淤积"

本文回顾总结了以往对黄河干支流河道冲淤特性的研究情况 ,利用所提出的冲淤临界流量与含沙量的关系与渭河下游、黄河下游进行了对比。以此为基础 ,勾画出了黄河干支流冲积河道“相对清水冲刷、相对浑水淤积”的物理图景 ,提出了多沙河流“相对清水冲刷、相对浑水淤积”的冲淤特性     

拉萨河水环境现状分析

在参考拉萨河近几年来的监测材料基础上，用气相色谱、离子色谱和等离子体发射质谱对所取水样进行了分析，确定了拉萨河水为重碳酸盐型水，通过对测定结果的讨论，认为人类活动已经影响了拉萨河的水质，提出了开发利用拉萨河应注意的问题，指出了保护拉萨河水环境的重要性。     

怒江水电基地的电力市场研究

怒江中下游干流河段落差集中 ,水量大 ,淹没损失小 ,交通方便 ,施工条件好 ,地质条件良好。规划装机容量2 13 2 0MW ,是我国重要的水电基地之一。到 2 0 2 0年 ,澜沧江中下游、金沙江中下游以及广西水电、四川水电、贵州水电基本得到大规模的开发 ;怒江将可能成为南方电网 ,乃至华中电网电力电量平衡的必不可少的电源。怒江水电基地是南方电网长远能源平衡的战略基地 ,“西电东送”的后续基地。怒江供电区域市场空间较大 ,送到受电地区的落地电价也具备一定的竞争力     

Confounding Effect of Flow on Estuarine Response to Nitrogen Loading

The total maximum daily load (TMDL) concept provides the basis for regulating pollution load from riverine sources to impaired water bodies. However, load is comprised of two components: flow and concentration. These two components may have confounding, or even conflicting, effects on waterbody attributes of concern. This is particularly the case for dynamic, advective systems, such as estuaries. Resolving these components is critical for properly predicting the response of impaired systems to watershed management actions. The Neuse River Estuary in North Carolina is an example of such an impaired system. Nitrogen has been identified as the pollutant of concern, and the process of developing a TMDL for nitrogen is underway. We, therefore, analyze the extensive data that have been collected for the Neuse River and estuary to investigate spatiotemporal relationships between river flow, riverine total nitrogen (TN) inputs, water temperature, dissolved inorganic nitrogen concentration, algal density, and primary productivity. Results support the belief that phytoplankton in the estuary are under substantial riverine control. However, the riverine TN concentration alone has only a minor role in determining estuarine chlorophyll concentration. River flow has a stronger influence, likely through its effects on down-estuary nitrogen delivery, residence time, salinity, and turbidity. These results imply that using riverine nitrogen load as the metric to evaluate watershed nutrient management may not be appropriate. While nitrogen controls should reduce loads in the long term, in the short term, river flow is the dominant component of load and has the opposite effect of nitrogen on algae at the up-estuary locations.