基于分布式水文模型的中小河流洪水预报技术   总被引：4，自引：3，他引：1  

刘志雨  侯爱中  王秀庆 《水文》2015,35(1):1-6

中小河流大多位于资料短缺的山丘区,洪水具有突发性强、汇流时间快、预见期短以及分布广的特点。中小河流洪水预报首要目的和任务是预警预报,预报方式应以自动预报为主,以实现及时预警,最大程度地避免人员伤亡,减轻灾害损失。本文分析了中小河流洪水预报的特点与难点,提出了中小河流洪水预报的思路及实用预报模型与方法,开展了基于分布式水文模型的中小河流洪水预报技术在新安江上游屯溪流域预警预报中的应用研究,以期为当前所开展的全国中小河流洪水预警预报系统建设提供参考。研究表明:分布式水文模型是资料短缺地区中小河流洪水预报的有效方法,基于分布式水文模型的洪水预报技术能够满足中小河流洪水自动预警预报的生产需要。  相似文献   

What should these rivers look like? Historical range of variability and human impacts in the Colorado Front Range,USA     

Ellen Wohl 《地球表面变化过程与地形》2011,36(10):1378-1390

Historical range of variability (HRV) describes the range of temporal and spatial variations in river variables such as flow regime or channel planform prior to intensive human alteration of the ecosystem. In mountainous river networks, HRV is most usefully applied to spatially differentiated geomorphic process domains with distinctive form and process. Using the Colorado Front Range as an example, three examples of how knowledge of HRV can assist river management and restoration are discussed. The examples involve instream wood load and channel morphology, beaver colonies and valley‐bottom form and process, and flow thresholds in regulated rivers. The question of what a river should look like – that is, what range of process and form the river included prior to intensive human alteration – can be addressed by (i) placing the river within a process domain, (ii) establishing correlations between form parameters that can be remotely sensed and reach‐scale process and form, so that the spatial extent, connectivity, and rarity of process domains within a river network or a region can be quickly assessed, (iii) inferring characteristics of the river prior to intensive alteration by documenting characteristics of the least altered reference rivers and by using proxy indicators of pre‐alteration conditions, and (iv) establishing process thresholds that must be exceeded to maintain form (e.g. flow thresholds to mobilize bed sediment). Once this context has been established, resource managers can better evaluate the options for restoring altered riverine form and function. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

大气环流模式（GCMs）在东南诸河流域的适用性评价     

刘文丰  徐宗学  李发鹏  刘星才  李秀萍 《福建地理》2011,(4):13-23

采用秩评分方法,选取NCEP再分析资料作为“实测”依据,以10个统计特征值为基础,评估了21个GCMs对东南诸河流域17个气候要素的模拟效果．结果显示：气候变量表现出不同的统计特征,GCMs对不同气候变量的模拟效果并不一致．与地面气象站点实测值对比,CSIRO：MK30、GFDL：CM21、GFDL：CM20、INM：CM30对降水和地面气温的模拟效果相对较好;流域高空气候要素的模拟效果更佳的模式有CGCM2．3．2、GISS：EH、BCCR：BCM20、GFDL：CM20对;综合所有气候变量,BCCR：BCM20、GFDL：CM20、CGCM2．3．2、GISS：EH的表现更优．优选出的GCMs可以为东南诸河流域气候变化的进一步研究提供科学依据．  相似文献   

大气环流模式（GCMs）在东南诸河流域的适用性评价     

刘文丰  徐宗学  李发鹏  刘星才  李秀萍 《亚热带资源与环境学报》2011,6(4):13-23

采用秩评分方法,选取NCEP再分析资料作为“实测”依据,以10个统计特征值为基础,评估了21个GCMs对东南诸河流域17个气候要素的模拟效果．结果显示：气候变量表现出不同的统计特征,GCMs对不同气候变量的模拟效果并不一致．与地面气象站点实测值对比,CSIRO：MK30、GFDL：CM21、GFDL：CM20、INM：...  相似文献   

Are artificial neural network techniques relevant for the estimation of longitudinal dispersion coefficient in rivers? / Les techniques de réseaux de neurones artificiels sont-elles pertinentes pour estimer le coefficient de dispersion longitudinale en rivières?     

《水文科学杂志》2013,58(1)

Abstract

Abstract Accurate application of the longitudinal dispersion model requires that specially designed experimental studies are performed in the river reach under consideration. Such studies are usually very expensive, so in order to quantify the longitudinal dispersion coefficient, as an alternative approach, various researchers have proposed numerous empirical formulae based on hydraulic and morphometric characteristics. The results are presented of the application of artificial neural networks as a parameter estimation technique. Five different cases were considered with the network trained for different arrangements of input nodes, such as channel depth, channel width, cross-sectionally averaged water velocity, shear velocity and sinuosity index. In the case where the sinuosity index is included as an input node, the results turned out to be better than those presented by other authors.  相似文献   

Differing controls on river‐ and lake‐water hydrogen and oxygen isotopic values in the western United States     

Anna King Henderson  Bryan Nolan Shuman 《水文研究》2010,24(26):3894-3906

Surface water oxygen and hydrogen isotopic values are commonly used as proxies of precipitation isotopic values to track modern hydrologic processes while proxies of water isotopic values preserved in lake and river sediments are used for paleoclimate and paleoaltimetry studies. Previous work has been able to explain variability in USA river‐water and meteoric‐precipitation oxygen isotope variability with geographic variables. These studies show that in the western United States, river‐water isotopic values are depleted relative to precipitation values. In comparison, the controls on lake‐water isotopic values are not well constrained. It has been documented that western United States lake‐water input values, unlike river water, reflect the monthly weighted mean isotopic value of precipitation. To understand the differing controls on lake‐ and river‐water isotopic values in the western United States, we examine the seasonal distribution of precipitation, evaporation and snowmelt across a range of seasonality regimes. We generate new predictive equations based on easily measured factors for western United States lake‐water, which are able to explain 69–63% of the variability in lake‐water hydrogen and oxygen isotopic values. In addition to the geographic factors that can explain river and precipitation values, lake‐water isotopic values need factors related to local hydrologic and climatic characteristics to explain variability. Study results suggest that the spring snowmelt runs off the landscape via rivers and streams, depleting river and stream‐water isotopic values. By contrast, lakes receive seasonal contributions of precipitation in proportion to the seasonal fraction of total annual precipitation within their watershed. Climate change may alter the ratio of snow to rain fall, affecting water resource partitioning between rivers and lakes and by implication of groundwater. Paleolimnological studies must account for the multiple drivers of water isotopic values; likewise, studies based on the isotopic composition of fossil material need to distinguish between species that are associated with rivers versus lakes. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Towards developing sediment quality assessment guidelines for aquatic systems: An Australian perspective     

A. V. Arakel 《Australian Journal of Earth Sciences》2013,60(4):335-369

Sediment at the sediment‐water interface of natural and man‐made waterways forms an integral part of the ecosystem because it is affected by a continuous flux of physical, chemical and biological components between the sediment, interstitial water and the overlying water column. Aquatic sediments contain records of past and present urban and rural runoff, chemical discharges and spills. In recent years sediment quality has received increasing attention following identification of the role of sediment as both a sink for pollutants and as a contaminant source with potential impacts on the quality of receiving waters. Research has indicated that the processes leading to remobilization of contaminated sediments in upstream reaches of a waterway may, through time, exert a significant influence on water quality in the downstream reaches. This, together with the cumulative effects due to contaminant input from point and non‐point source discharges, have dramatic effects on water quality and thus on ecosystem structure and functioning.

The problems associated with elevated concentrations of many hazardous organic and inorganic compounds have resulted in the establishment of aquatic sediment quality criteria and management guidelines in many overseas countries, with the objectives being the reduction and elimination of adverse environmental effects and human health risks associated with contaminated sediments. Whereas more than 70% of the Australian population is clustered around the coastal waterways, little is known about the role of sediments as a repository of environmental pollutants and/or as a source of adverse impacts on water quality and the health of our rivers. The paucity of knowledge on the quality of aquatic sediment highlights the need for the development of coherent guidelines for sediment quality assessment and management of contaminated sites, which are consistent with Australian environmental conditions and land use features.

A comparative evaluation of sediment quality information from eight coastal rivers along the east coast of Australia, presented in this paper, indicates the possibility for establishing a framework for regional sediment quality assessment. This may be achievable by using textural and compositional attributes of bottom sediments in depositional areas to develop databases on the loading and concentration trends of nutrients and contaminants. Regional variability in sediment quality determinants are shown to reflect the influence of catchment hydrology, lithology and land use on nutrient and contaminant concentration trends. Locally, the loading and partitioning behaviour of sediment‐bound contaminants is largely controlled by the nature and the extent of interactions occurring at the sediment‐water interface within individual depositional units.

The concept of ‘Sediment Effect Zone’ is introduced to provide a compartmental approach to the characterization of aquatic sediments and depositional environments in different hydrologic zones. This approach offers a rational basis for follow‐up chemical and biological assessments to establish sediment quality standards and management guidelines. Because of the complex influences of environmental, methodological and statistical factors on defining the sediment variability, the need for implementing proper quality control measures from early stages of design of a sediment quality assessment program is highlighted.  相似文献   

Modelling flow resistance in vegetated streams: review and development of new theory     

Julian C. Green 《水文研究》2005,19(6):1245-1259

Aquatic macrophytes are often the dominant factor influencing flow conditions within the channels they occupy. Existing knowledge of how stream plants affect the flow is outlined, and the different scales at which vegetation resistance operates are proposed. Resistance is shown to be a function of the size of the plants, their structural properties, location in the channel, and the local flow conditions. Current models to calculate this composite resistance effect are assessed in the light of theoretical considerations of the nature of vegetation resistance. New theory is also presented, which demonstrates the non‐linear relationship between channel resistance and the proportion of the channel occupied by vegetation. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

Efficient methods of discharge measurements in rivers and streams based on the probability concept     

Chao‐Lin Chiu  Shih‐Meng Hsu  Ning‐Chien Tung 《水文研究》2005,19(20):3935-3946

Regularities exist in fluid flows and can be represented by a set of constants. These constants are functions of the parameter of a probability distribution that exhibits resilience and stability under various flow conditions. Together, these regularities form a network and interact with each other, such that if one is known then the others can be determined from it. The regularities and their network explain the various fluid‐flow phenomena and can be used in analysis of rivers and streams. For example, they can be used as the basis to develop simple and efficient methods of discharge measurements as presented herein, which only require velocity sampling at a single point on a water surface or a few points on a single vertical. Because of their simplicity and the short time requirement, these methods can be easily automated for collecting discharge data in unsteady, high flows that are badly needed for real‐time flow forecasting and design of flood control structures, and for advancing the fundamental, scientific knowledge in hydrology. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

北京城区河湖水质分析   总被引：11，自引：1，他引：10  

杜桂森  吴玉梅  扬忠山  武佃卫  刘靖 《湖泊科学》2005,17(4):373-377

调研结果显示,2003年北京城区河湖(11个监测水体)总磷、总氮含量分别为0．142mg/L、1．481mg/L,已达到比较 严重的富营养状态．北京城市河湖属于藻型水体,初级生产力主要决定于浮游藻类的群落结构与密度．河湖水体中浮游 藻类密度为37867．82×10~4cells/L,其群落由蓝藻(Cyanophyta)、绿藻(Chlorophyta)、硅藻(Bcillariophyta)、甲藻(Pyrrophy— ta)、隐藻(Cryptophyta)、黄藻(Xanthophyta)、金藻(Chrysophyta)和裸藻(Eugleniphyta)构成．群落中蓝藻占绝对优势 (89．54%)．在近几年的夏秋季连续发生程度不同的微囊藻(microcystis)水华,对水体功能和城市景观造成了不良影响． 主要原因是：(1)氮磷和有机物的污染,(2)给城市河湖补给的水量少,(3)河湖生态系统被损害,水体自净能力差．本文 对如何改善北京城市河湖水质提出了建议．  相似文献