Relative Role of Lake and Tributary in Hydrology of Lake Superior Coastal Wetlands

Despite the documented importance of hydrodynamics in influencing the structure and function of Great Lakes coastal wetlands, systematic assessments of coastal wetland hydrology are lacking. This paper addresses this gap by describing patterns in lake and tributary inputs, water residence times, and mixing regimes for a suite of western Lake Superior wetlands that differ in the amount of tributary and seiche flow they receive. We show that variability in tributary flows among wetlands and over time is far greater than variability in seiche-driven water movements, and that the amount of tributary flow strongly influences wetland hydrology via effects on water mixing and residence times, seiche size, mouth closures, and relative amounts of main and off-channel areas. Wetland seiche amplitudes were reduced in systems with small mouth openings and wetland mouth size was correlated with tributary flow. All wetlands experienced seiche-driven water level oscillations, but there was lake water intrusion only into those wetlands where tributary outflow was small relative to the seiche-driven inflow. Wetlands in settings exposed to long-shore sediment transport exhibited periodic mouth closures when stream flows were low. The absolute and relative size of lake and tributary inputs must be explicitly considered in addition to wetland morphology and landscape setting in studies seeking to understand determinants of coastal wetland structure, function, and response to anthropogenic stressors.     

Hydrology and Nutrient Enrichment at Two Coastal Lagoon Systems in Northern Greece

The lagoons of N.E. Greece, located on the western side of NestosRiver, and of N.W. Greece, located at the lower reaches of Kalamas River, are among the most important shallow, semi-enclosed ecosystems in Northern Greece. The temporal variability of nutrients at both lagoonal systems shows the strong influence of fresh water discharge on water quality. Nutrient enrichment factors showed that nitrites and ammonium were six times higher at the lagoons of N.W. Greece than those observed at N.E. Greece, while phosphates were forty times higherat Nestos River lagoons. The flushing half-life was calculatedbased on a combination of hydrological and tidal processes, foreach lagoon of these two systems, allowing for the assessment ofwater quality changes. Proper management measures for both systems should focus on the control of fresh water quality entering the lagoons, the reduction of phosphoric fertilizers used by agriculture and the better oxygenation of the water column. One way to eliminate massive fish deaths during the winter in N.E. Greece is also the transfer of fresh, warm groundwater, while bathymetric modifications and channel wideningare needed at the lagoons of N.W. Greece.     

Monitoring Water Quality and Assessment of Land-Based Nutrient Loadings and Cycling in Kavala Gulf

The results of a systematic and intensive nutrient monitoring program are reported, which took place during the period 1997–1999 in Kavala Gulf, Northern Greece, having as a general task to study the impact of the various human activities on the nutrient loadings and cycling of the aquatic environment. A nutrient budget box model was used to estimate the annual capacity of Kavala Gulf to store and transform dissolved inorganic nitrogen and phosphorus, aiming at understanding the biogeochemical processes taking place in the area of interest. Point sources of nutrients from two municipal wastewater treatment plants (Kavala and Palio Seawage Treatment Works) and a phosphoric fertilizer producing industrial facility (PFP), as well as non-point sources from agricultural activities, seem responsible for the increased concentrations of dissolved inorganic nitrogen and phosphorus. Seasonal N:P-ratios suggest that nitrogen is the limiting nutrient during the summer, autumn and winter and phosphorus during the spring. The annual nutrient budget model revealed that Kavala Gulf is presently slightly autotrophic with nitrogen fixation exceeding denitrification.     

河流水文学若干研究领域的回顾与展望

就 2 1世纪的产汇流理论、流域定量地貌、河流洪水、河流泥沙、河流热状况与冰情、河流资源利用、河流水质与河流生态环境等河流水文学主要研究领域的发展前景作了初步的展望 :要进一步揭示不同气候和下垫面条件下的产汇流规律 ,研制预测功能强的流域水文模型 ,发展和应用数字流域 ,深入揭示复杂条件下的洪水运动规律 ,提出高精度的分析计算方法 ;水流动力学与泥沙动力学相耦合的产沙计算方法将得到实际应用 ,河流输沙机理将进一步被揭示 ;继续探索河冰形成及河流冰情变化的热力学和水力学机理 ,完善冰凌数学模型 ,进一步揭示河流水流挟带污染物质的运动机理 ,完善水质模型 ,提高计算精度 ;要采用多学科综合的手段 ,深入探讨人类活动对河流生态系统的影响     

小流域综合治理在水土保持中的特殊作用及发展途径

小流域综合治理在水土保持工作中的主要作用是 :提高土地生产力 ,使土地结构趋于合理 ,具有明显的拦沙效果 ,减轻水旱灾害等 .根据中国的具体情况 ,提出了几条对策 ,包括搞好农田基本建设 ,发展林果业 ,搞好植被建设和水土保持产业化 ,全方位综合治理等 ,以达到生态效益、经济效益、社会效益的互相统一 .     

引黄工程后期的水文水资源工作

山西省万家寨引黄工程（以下简称引黄工程）南干线的骨干工程即将完工，预计可在2002年底通水至太原，但在通水前，还有一些必要的水文水资源工作需要引起重视并应及早开展，其主要工作包括引黄工程沿程的水量和水质监测、泥沙测验、对汾河上游水资源的统一调度和管理，并提出应成立汾河上中游水务局，从行政统一本区域的水资源调度及管理工作等建议。     

水文基础设施建设单位合同管理若干问题探讨

对水文基础设施项目建设合同管理内容、合同管理类型、合同管理体系、建设单位合同管理的主要职责等问题进行探讨,提出了水文基础设施建设单位合同管理应注意的问题.     

黄河三角洲柽柳灌丛对土壤盐分养分的影响

为研究黄河三角洲柽柳灌丛对土壤盐分和养分的影响,以柽柳为研究对象,在固定样地连续调查的基础上,对研究区柽柳灌丛冠下、冠缘和灌丛间的土壤盐分、养分指标和富集率进行了分析。结果表明:柽柳冠下、冠缘表层(0～5 cm)土壤全盐含量小于灌丛间的,易形成"盐谷"效应,而灌丛间易形成"盐岛"效应;柽柳对盐分离子具有选择吸收性,不同盐分离子在冠下、冠缘、灌丛间对于"盐谷"效应、"盐岛"效应的贡献率不同,Cl~-贡献最大,Na~+次之;土壤全盐含量、电导率及钠、钾、钙、镁、氯、硫酸根离子含量具有明显表聚现象;柽柳冠下、冠缘表层(0～5 cm)土壤有机质、速效氮、速效磷、速效钾含量均高于灌丛间的,易形成"肥岛"效应,而灌丛间易形成"肥谷"效应;随着土壤深度的增加,土壤有机质、速效氮、速效磷等含量逐渐降低,呈现出明显的表聚特征;柽柳能够有效降低土壤盐分、增加土壤养分而改善土质。     

Particle Transport,Nutrient Cycling,and Algal Community Structure Associated with a Major Winter-Spring Sediment Resuspension Event in Southern Lake Michigan

Over the past decade, intermittent satellite imagery revealed the presence of an extensive plume of resuspended sediments in late winter-early spring with a clear offshore projection coinciding with the region of maximum sediment accumulation in the lake. The large scale of the plume implied that this process was important in sediment, and associated constituent, cycling and transport, but it had never been sampled due to severe conditions. The onset of the 1996 event coincided with a major March storm. Within a few days the plume was approximately 10 km wide and over 300 km in length, implying that the source of the reflective materials was widely distributed. An estimate of the total mass of resuspended sediment, 12 days after the storm, was similar to the annual external load of (sand-free) particulate material to the southern basin. The high turbidity plume persisted for over a month, progressing northward along the eastern shore with a major offshore transport feature. Sediment traps within this feature recorded a major mass flux event. The plume was sampled on two occasions and was found to contain 5 to 10 times as much suspended matter as open-lake locations outside the visible plume. Total particulate phosphorus was high within the plume making this episodic process important in sedimentwater exchange. The diatom community structure within the plume was significantly different from outside the plume and was characteristic of more eutrophic waters. Abundance of non-diatom phytoplankton and microbial food web organisms were highest at the plume edge. The episodic nature of this process makes it difficult to sample, but the scale makes it important in designing monitoring programs and massbalance modeling efforts.     

水文与水资源专业课程体系构建中应关注的几个问题

就如何科学、合理地构建“水文与水资源”专业课程体系 ,提高该专业人才培养质量 ,结合我国目前水资源、水环境的状况提出几个值得关注的问题 ,力图从该专业课程体系改革中找到准确的切入点     

鞍山地区地质、气象及水文特征分析

研究鞍山地区所发生的霜冻、干旱和洪涝灾害,都与这个地区的自然因素有着密切的关系。因此,掌握鞍山地区的地质、气象及水文特征,对于鞍山市的防汛抗旱、防灾减灾工作具有重大的指导意义。     

Nutrient Contributions from Alluvial Soils Associated with the Restoration of Shallow Water Habitat in the Lower Missouri River

The Missouri River has been extensively altered as the result of channelization, bank stabilization, and the construction of six main stem reservoirs. In response to the resultant habitat loss, the US Army Corps of Engineers was tasked with restoring approximately 8100 ha of shallow water habitat (SWH), in part, for the benefit of the endangered pallid sturgeon (Scaphirhynchus albus). Construction of off‐channel habitats involves the removal and disposal of excavated alluvium either by direct discharge into the river or by secondary erosion, which raised concerns regarding the introduction of sediment and associated nutrients into the Missouri River. Soils from nine side‐channel chutes were sampled to represent nutrient concentrations from habitat restoration activities. Soils from 12 historically undisturbed sites were also sampled to represent reference conditions in the Missouri River flood plain. The results of this study indicate that nutrient characteristics of soils from selected SWH locations generally are similar to those of historically undisturbed soils. The estimated mass of total phosphorus from chutes accounted for 1.9% of Missouri River and 0.5% of Mississippi River total phosphorus loads during the 1993–2012 analysis period. The mass of nitrate, the constituent most closely related to gulf hypoxia, was 0.01% or less of the Missouri and Mississippi River nitrate loads. Sediment volumes from the chutes accounted for 3.1 and 1.5% of total suspended loads from the Missouri and Mississippi Rivers. Overall, the introduced sediment from side‐channel chute construction associated with SWH restoration accounts for a small portion of total nutrient and sediment transport in the Missouri and Mississippi Rivers. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. River Research and Applications published by John Wiley & Sons, Ltd.     

湖南水文发展的几点思考

近几年来，湖南水文发展迅速，但在前进中有些问题值得思考，文章对湖南水文现阶段存在的体制、投入、行业管理、服务功能、水资源管理、人才培训六方面进行了简要分析，欲寻求一条解决现存不利因素、推行水文发展的有效途径。     

三峡工程施工水文气象服务

三峡工程坝区水文气象服务体系由坝区水文测报、水情预报和气象观测与预报三大部分组成，其主要任务是准确及时地为三峡总公司和有关部门、工程施工监理、主要施工单位提供坝区水情气象信息，供生产安排决策参考，以及采取相应措施预防和减轻灾害造成的损失，确保工程安全渡汛。     

深化改革加速实现水文现代化--《全国水文事业发展规划》简介

为了促进水文事业的健康发展,使其更好地适应国民经济建设和社会发展的需要,并指导全国水文工作,根据水利部有关精神,水利部水文局组织有关单位开展了《全国水文事业发展规划》的编制工作。     

Hydrology of the Jordan River Basin: Watershed Delineation, Precipitation and Evapotranspiration

The Jordan River Basin is shared between Lebanon, Syria, Israel, Jordan and Palestine; the waters of the River are a critical resource for the future water security of the co-riparians. Because of the political situation in the region, field data such as rainfall and evapotranspiration are very difficult to obtain making the use of remote sensing and Geographic Information System (GIS) very useful to study water availability in the basin. The approach used in this paper integrates recently compiled data derived from satellite imagery (evapotranspiration, rainfall, and digital elevation model) into a GIS geodatabase to measure the contribution of each riparian country to the total available water in the basin.     

水文学的科学前沿与研究需求

水文学学科发展,要围绕全面建设小康社会的国家目标,根据社会经济协调发展、确保国家粮食、水资源与生态环境安全、实现可持续发展的战略要求,并立于当代世界科技发展前沿.水文学学科在江河治理、防汛抗旱、水资源开发利用中有着重要的基础作用,而目前我国的水文科技还不能适应新时期社会经济发展的要求,与世界水文科技相比,仍有一定差距,应加强对水文学基础的科学研究.     

Study of Hydrology and Drought in the Flood Region of Sudan

ABSTRACT

An attempt is made to thoroughly investigate the important hydrological features ofhe flood region that is located in the southern part of Sudan. The hydrologic data that were used in the study include temperature, precipitation, sunshine duration. radiation, humidity, wind speed, and evaporation. The investigation also includes the stream flow records of the Nile River in the region. In this region, a huge amount of the Nile water is lost by evaporation and overspilling. The hydrological data of Malakal meteorological station, taken as the index station, and the long-term flow data of the White Nile and its principal tributary, the Sobat, have been analyzed. The effect of changes in the behavior of the hydrological factors on the degree of aridity is also assessed. The study clearly indicates significant changes in the hydrological behavior of the region characterized by an increase in temperature levels and a substantial reduction in rainfall and river flows.     

Challenges and Solutions of Urban Hydrology in Beijing

Since the reform and opening-up in 1978, the city of Beijing as the capital of China has been going through a rapid urbanization. Water as the public, fundamental and strategic resources for the social and economic development as well as the survival basis of human and surroundings, is constrained to the urbanization of Beijing. In order to solve the hydrological challenges by urbanization, as the municipal water information service, Beijing Hydrological Center (BHC) is currently focusing on the safe water supply based on the mega-city hydrological development concept and making efforts to deal with new hydrological problems caused by the rapid urbanization. After years of study on theories and practices, the solutions to intense water scarcity, such as new well fields development, South-North water diversion, water resource and quality monitoring networks improvement, reclaimed water usage and so on, have provided strong support for Beijing turning into an international city. In this paper, the current water problems of Beijing are described in details on water shortage, water quality deterioration, drinking water safety and problems concerning water drainage system and flood control. The experiences of hydrometric, water quality and groundwater monitoring networks are provided as measures for water resources management. Additionally, the previous and current research work which provides technical and scientific support for decision-making of water resources management in Beijing is discussed in this paper.