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101.
C.A.F. Marques J.A. Ferreira A. Rocha J.M. Castanheira P. Melo-Gonçalves N. Vaz J.M. Dias 《Physics and Chemistry of the Earth》2006,31(18):1172-1179
The singular spectrum analysis (SSA) technique is applied to some hydrological univariate time series to assess its ability to uncover important information from those series, and also its forecast skill. The SSA is carried out on annual precipitation, monthly runoff, and hourly water temperature time series. Information is obtained by extracting important components or, when possible, the whole signal from the time series. The extracted components are then subject to forecast by the SSA algorithm. It is illustrated the SSA ability to extract a slowly varying component (i.e. the trend) from the precipitation time series, the trend and oscillatory components from the runoff time series, and the whole signal from the water temperature time series. The SSA was also able to accurately forecast the extracted components of these time series. 相似文献
102.
103.
国际水文科学研究的新进展 总被引:30,自引:0,他引:30
在介绍第七届国际水文科学大会关注热点问题的基础上,总结了近4年来国际水文科学研究的新进展,主要包括:无资料流域水文预测,不确定性、非线性和尺度问题,生态水文学,水文模型及资料获取与参数识别,气候变化的水文响应,水资源可持续利用,城市水文水资源,同位素技术和遥感技术在水文学中应用;提出未来水文学研究的展望。 相似文献
104.
运用不同种类和不同时相的遥感图像,可以获取大量的水文、环境信息及动态变化规律。这样,既能为新线桥渡方案比选提供依据;也可在营业铁路桥渡洪水灾害成因分析和综合整治中发挥重要作用。 相似文献
105.
Jagdish Krishnaswamy Michael Lavine Daniel D. Richter Karl Korfmacher 《Advances in water resources》2000,23(8):2078
Modeling of sediment transport in relation to changing land-surface conditions against a background of considerable natural variability is a challenging area in hydrology. Bayesian dynamic linear models (DLMs) however, offer opportunities to account for non-stationarity in relationships between hydrologic input and basin response variables. Hydrologic data are from a 40 years long record (1951–1990) from the 5905 km2 Yadkin River basin in North Carolina, USA. DLM regressions were estimated between log-transformed volume-weighted sediment concentration as a response and log-transformed rainfall erosivity and river flow, respectively, as input variables. A similar regression between log-transformed river flow and log-transformed basin averaged rainfall was also analyzed. The dynamic regression coefficient which reflects the erodibility of the basin decreased significantly between 1951 and 1970, followed by a slowly rising trend. These trends are consistent with observed land-use shifts in the basin. Bayesian DLMs represent a substantial improvement over traditional monotonic trend analysis. Extensions to incorporate multiple regression and seasonality are recommended for future applications in hydrology. 相似文献
106.
This study presents the preliminary results of the local energy budget and dynamic characteristics of the surface atmospheric boundary-layer (SBL) during the WELSONS (wind erosion and losses of soil nutrients in semiarid Spain) experiment. Some Mediterranean regions suffer land degradation by wind erosion as a consequence of their particular soil and climate conditions and inappropriate agricultural practice. In Spain, where land degradation by water erosion is well known, the lack of field studies to quantify soils losses by wind erosion resulted in the European Community organizing a scientific program for this specific issue. The European programme known as WELSONS was devoted to study the wind erosion process in central Aragon (NE Spain). This multidisciplinary experiment, which began in 1996 and finished in 1998, was carried out over an agricultural soil which was left fallow. Within the experimental field, two plots were delimited where two tillage treatments were applied, a mould-board ploughing (or conventional tillage denoted CT) and chisel ploughing (reduced tillage denoted RT). This was to study on bare soil the influence of tillage method on surface conditions, saltation flux, vertical dust flux, erosion rates, dynamics characteristics such as friction velocity, roughness length, etc., and energy budget. The partitioning of the available energy, resulting from the dynamics of the SBL, are quite different over the two plots because of their own peculiar soil and surface properties. The first results show that the RT treatment seems to provide a wind erosion protection. Because of the long data recording time and particular phenomena (formation of a crust at the soil surface, very dry conditions, high wind speed for instance), these microclimatological data acquired during the WELSONS programmes may be helpful to test atmospheric boundary-layer models coupled with soil models. 相似文献
107.
Samuel Beskow Luis Carlos Timm Vitor Emanuel Quevedo Tavares Tamara Leitzke Caldeira Leandro Sanzi Aquino 《水文科学杂志》2013,58(14):2567-2578
ABSTRACTThe objective of this study was to evaluate, based on a data-scarce basin in southern Brazil, the potential of the Lavras Simulation of Hydrology (LASH) model for estimating daily streamflows, annual streamflow indicators and the flow–duration curve. It was also used to simulate the different runoff components and their consistency with the basin physiographical characteristics. The statistical measures indicated that LASH can be considered suitable according to widely used classifications and when compared with other studies involving hydrological models. LASH also showed satisfactory results for annual indicators, especially for maximum and average annual streamflows, as well as for the flow–duration curve. It was found that the model was consistent with the basin characteristics when simulating runoff components. The results obtained in this study allowed us to conclude that the LASH model has the potential to aid practitioners in water resources management of basins with scarce data and similar soil and land-use conditions.
Editor A. Castellarin; Associate editor Y. Gyasi-Agyei 相似文献
108.
国际水文计划发展与中国水资源研究体系构建 总被引:9,自引:1,他引:8
国际水文研究计划(International Hydrological Program; IHP) 是国际水资源研究展示的大舞台,其发展是国际水资源研究发展的集成体现。国际水文计划的研究历程和发展态势表明,水资源研究已从单学科研究过渡到了多学科的集成研究。随着社会因子的增加,水资源研究已经成为一项系统工程。从水资源研究的发展来看,中国水资源研究整体上要滞后于国际水资源研究的步伐,但发展态势较好。中国水资源研究体系应具有显著的圈层结构特征,变化环境中的-水资源研究体系过程与机理是水循环研究的核心,构成了圈层结构的内圈;基于生态水文过程的水资源保育与保障体系是中国水资源研究体系的第二圈层;基于自然-人工二元演化模式的水资源配置体系,基于现代理、化、生技术和信息技术的节水体系以及基于市场机制的水资源高效利用的激励体系构成了水资源研究体系的第三圈层。在上述三个圈层研究的基础上,进行基于现代信息技术和管理技术的水资源综合决策和集成管理研究,以及基于现代传媒技术的水资源教育与培训体系构成了中国水资源研究体系的最高层次,是圈层结构中的外圈层。 相似文献
109.
Characterization of surface water and groundwater in the Damascus Ghotta basin: hydrochemical and environmental isotopes approaches 总被引:1,自引:0,他引:1
Zuhair Kattan 《Environmental Geology》2006,51(2):173-201
The hydrochemistry of major ions and environmental isotope compositions (18O, 2H and tritium) of water samples have been used to investigate the characteristics of rainfalls, surface water and groundwater in the Damascus Ghotta basin. The groundwater salinity in the Damascus Ghotta basin gradually increases, as the groundwater moves from western to south-eastern and north-eastern parts of the basin. A strong relationship exists between the Barada river and the surrounded groundwaters, mainly in terms of recharge by infiltration of surface waters. The groundwater quality in the Adra region has clearly become less saline as a result of establishment of the sewage-water-treatment station in this area since 1997. The uncommon depleted stable isotope concentrations in the vicinity of Al-Ateibeh Lake and Adra valley could be interpreted as a result of sub-flow recharge from the Cenomanian–Turonian aquifer, mostly prolonged along the Damascus Fault, which forms direct contact between this complex and the Quaternary alluvium aquifers. The extensive exploitation of water from the Cenomanian–Turonian aquifer for drinking water supply would shortly be reflected by a gradual decline of the groundwater table in the Damascus Ghotta basin. Amelioration of water quality in the Damascus basin still requires further management strategies and efforts to be taken within the forthcoming years. 相似文献
110.
Historical and modern scientific contexts are provided for the 2006 Binghamton Geomorphology Symposium on the Human Role in Changing Fluvial Systems. The 2006 symposium provides a synthesis of research concerned with human impacts on fluvial systems — including hydrologic and geomorphic changes to watersheds — while also commemorating the 50th anniversary of the 1955 Man's Role in Changing the Face of the Earth Symposium [Thomas, Jr., W. L. (Ed.), 1956a. Man's Role in Changing the Face of the Earth. Univ. Chicago Press, Chicago. 1193 pp]. This paper examines the 1955 symposium from the perspective of human impacts on rivers, reviews current inquiry on anthropogenic interactions in fluvial systems, and anticipates future directions in this field.Although the 1955 symposium did not have an explicit geomorphic focus, it set the stage for many subsequent anthropogeomorphic studies. The 1955 conference provided guidance to geomorphologists by recommending and practicing interdisciplinary scholarship, through the use of diverse methodologies applied at extensive temporal and geographical scales, and through its insistence on an integrated understanding of human interactions with nature. Since 1956, research on human impacts to fluvial systems has been influenced by fundamental changes in why the research is done, what is studied, how river studies are conducted, and who does the research. Rationales for river research are now driven to a greater degree by institutional needs, environmental regulations, and aquatic restoration. New techniques include a host of dating, spatial imaging, and ground measurement methods that can be coupled with analytical functions and digital models. These new methods have led to a greater understanding of channel change, variations across multiple temporal and spatial scales, and integrated watershed perspectives; all changes that are reflected by the papers in this volume. These new methods also bring a set of technical demands for the training of geomorphologists. The 2006 Binghamton Geomorphology Symposium complements the 1956 symposium by providing a more specific and updated view of river systems coupled with human interactions. The symposium focuses on linkages between human land use, structures, and channel modification with geomorphology, hydrology, and ecology. The emergence of sustainability as a central policy guideline in environmental management should generate greater interest in geomorphic perspectives, especially as they pertain to human activities. The lack of theories of anthropogeomorphic change, however, presents a challenge for the next generation of geomorphologists in this rapidly growing subfield. 相似文献