摘要:

Two network-design technologies are compared by random sub-sampling of actual streamflow data. The technologies, Network Analysis for Regional Information (NARI) and Network Analysis Using Generalized Least Squares (NAUGLS), have a common objective, viz. to maximize regional information within a limited budget and time horizon. The data used for intercomparison are from a network of 146 streamgauges in the central part of the United States. In general, the results for the illustrative example indicate that the NAUGLS method conveys more information than the NARI method to the network designer interested in maximizing regional information about mean annual flows with a limited budget.

ISSN:0262-6667    

DOI:10.1080/02626669109492504

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The methods of simple and disjunctive kriging are applied and compared in the estimation of optimum locations of recording raingauges as part of a network for the determination of storm characteristics to be used in forecasting and design. Some advantages are shown but problems arise when there are large differences in storm structures and movements. Another source of uncertainty is in the modelling of the semi-variogram. Application is made to the management of an area of the Severn-Trent water basin, UK, with 13 autographic raingauges.

ISSN:0262-6667    

DOI:10.1080/02626669109492505

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Le portugais Estevão Cabral (1734–1811) a construit, en 1786, un moulinet lui permettant de mesurer la vitesse de l'eau à différentes profondeurs et de calculer ainsi le débit des rivières. Cabrai a été le premier chercheur qui ait utilisé un moulinet pour mesurer la vitesse de l'eau au-dessous de la surface libre, les moulinets à roue à ailettes planes utilisés auparavant ne pouvant que mesurer la vitesse à la surface. Il a aussi été le premier chercheur à soutenir que la vitesse dans les écoulements a surface libre croît depuis la surface jusqu'à un maximum à partir duquel elle décroît vers le fond.

ISSN:0262-6667    

DOI:10.1080/02626669109492506

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Regional effects of greenhouse warming on water resources, and more specifically on surface runoff, are assessed for a mountainous region of central Greece comprising four drainage basins by using a conceptual model and plausible hypothetical scenarios of temperature and precipitation change. Results show considerable sensitivity of runoff characteristics to climate change and indicate certain basin morphoclimatic characteristics such as snow cover, basin aridity and morphology, runoff coefficients etc., which modify considerably basin response. Research work is complemented by assessing the climate change impacts on water management works of the area. This second part of the work is published separately in the following paper in this issue.

ISSN:0262-6667    

DOI:10.1080/02626669109492507

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The sensitivity of some critical water management issues, such as reservoir storage and hydroelectric production, to climatic variability and change on a regional basis is analysed and presented. This is the second of two papers presented in this issue dealing with the regional hydrological effects of climatic change. By using a set of plausible hypothetical climatic scenarios to represent both greenhouse warming and precipitation changes, the sensitivity of the guaranteed annual fresh water and energy supply levels has been evaluated under conditions of altered runoff for four connected multi-purpose reservoirs in central Greece. It is shown that reservoirs designed and operated under current climatic conditions are, in general, affected by the climatic changes examined. A dramatic increase of the risk associated with the annual guaranteed quantity of water supply and energy production would occur if greenhouse warming were accompanied by a reduction in annual precipitation. Significant increases of storage volume would then be needed to maintain existing water and energy yields at tolerable risk levels.

ISSN:0262-6667    

DOI:10.1080/02626669109492508

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

A new procedure, the method of lower-bound (MLB), is proposed for determining the design quantileXp.The basic concept is first to determine an estimateâQof the location parameteraQusing the probability weighted moment (PWM) method, and then to transform the variableXfrom the original(X)space to a new (Y) space by usingY = ×—âQ.The variableYis considered to have a two parameter gamma distribution. InY-space, the two parameters are estimated by the PWM or an autocovariance method, then transformed from theY-space to theX-space. Results from the Monte Carlo experiments show that the MLB estimates are less biassed than comparable moment estimates and maximum likelihood estimates, and more efficient than those of PWM for design quantilesXp.

ISSN:0262-6667    

DOI:10.1080/02626669109492509

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626669109492510

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626669109492511

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626669109492512

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626669109492513

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor