摘要:

This paper deals with specific hydrological problems in large and international river basins. It considers the peculiarities of the hydrology of such basins and the consequences for water resources management. Reviewing the anthropogenic impacts and the availability of data, the necessity of international cooperation with the aim of preventive protection of water is stressed.

ISSN:0262-6667    

DOI:10.1080/02626669309492636

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A statistical model comprising nine different probability distributions used especially for flood frequency analysis was applied to annual flood peak series with at least 30 observations for 11 unregulated streams in the Rhine Basin in Germany and two streams in Scotland. The parameters of most of those distributions were estimated by the methods of maximum likelihood and probability-weighted moments. The distributions were first compared by classical goodness-of-fit tests on the observed series. Next, the goodness of predictions of the extreme right-tail events by all the models were evaluated through detailed analyses of long synthetically generated series. The general extreme value and 3-parameter lognormal distributions were found to predict the rare floods of return periods of 100 years or more better than the other distributions used. The general extreme value type 2 and log-Pearson type 3 (when skewness is positive) would usually yield slightly conservative peaks. The Wakeby distribution also gave peaks mostly on the conservative side. The log-logistic distribution with the method of maximum likelihood was found to overestimate greatly high return period floods.

ISSN:0262-6667    

DOI:10.1080/02626669309492637

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Methods for extrapolating runoff series are important in order to gain maximum information from hydrological observations. The main disadvantages of traditional methods are that they are subjective and often time consuming. In this paper, empirical orthogonal functions (EOF) are adapted for the extension of time series. By a linear transformation of a set of runoff series from a region, a new set of series, EOFs, describing the runoff variations in time, and a set of weight coefficients describing the spatial variations, are created. Using this information it is possible to extend a runoff series within the region. A study has been carried out using Norwegian runoff series of daily values. The method was compared both to regression and to use of a conceptual model. In general the EOF method gives results as good as the traditional methods, and the amount of work involved is minimized while the objectivity is maximized.

ISSN:0262-6667    

DOI:10.1080/02626669309492638

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

By analysing the hydrographs of karst springs it is possible to identify aquifer characteristics and, accordingly, the main features of a karst rock-fissure massif. Consequently, relevant data can be obtained by analysing hydrograph recession curves. This paper presents a detailed analysis and explanation of numerous cases of break points on recession curves via various values of the recession coefficient α in Maillet's (1905) equation. The paper also identifies the relationship between α and a linear reservoir coefficient by employing groundwater hydrograph methods. It is shown that the linear reservoir coefficient changes with time in accordance with changes of the flow conditions in the karst massif.

ISSN:0262-6667    

DOI:10.1080/02626669309492639

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626669309492640

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626669309492641

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626669309492642

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626669309492644

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626669309492645

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626669309492635

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor