摘要:

Rainfall and runoff depths were examined for 763 storms on 26 urban basins located in 12 countries. For 17 of the basins, impervious surfaces were the major contributors to storm runoff. These basins were generally smaller than 25 ha and had small to medium storms in the data set. Nine basins had significant amounts of runoff from pervious as well as impervious surfaces. Eight of these basins are located in Australia. For all 26 basins, plots of rainfall and runoff depths were used to estimate the effective impervious area and the impervious area initial loss. The data plotted close to a single straight line on all basins, indicating that the effective impervious area remained constant for all storm sizes. The effective impervious fraction was related to total impervious area and the directly connected impervious fraction estimated from maps. For the basins with pervious runoff, the depth of rain in the storm was the most important factor in determining pervious runoff for rainfalls less than 50 mm, while for larger storms other factors including rainfall intensity and antecedent wetness were also found to be significant.

ISSN:0262-6667    

DOI:10.1080/02626669309492699

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

La région nord-orientale de l'Algérie est caractérisée par un climat méditerranéen de transit, marqué par des oscillations saisonnières (en été, c'est un climat subtropical faisant de la saison chaude une des plus longues, et en hiver, il s'apparente beaucoup plus aux caractéristiques de la zone tempérée). Dans la région de Skikda, cette nuance, conjuguée à un relief très accusé, confère à la pluviosité de très grandes irrégularités spatio-temporelles. La forme des précipitations météoriques a un caractère torrentiel. La prise en charge des problèmes de l'eau en milieu rural nécessite la mise en place de moyens permettant l'approche hydrologique par des méthodes performantes. Les carences des données pluviométriques posent d'énormes difficultés à l'aménageur particulièrement dans le cadre des études d'assainissement agricole. Deux paramètres utiles dans cette optique ont été mis en évidence dans cet article. Le premier paramètre concerne le module pluviométrique moyen annuel qui intervient dans de larges proportions en hydrologie, et où son estimation est tributaire d'un réseau dense de pluviomètres régulièrement installés ou d'interpolations à partir de cartes pluviométriques, qui, dans le contexte géographique de la région, conduisent à des résultats peu précis et quelquefois erronés. Dans cette optique, la recherche des corrélations interfactorielles est la solution toute indiquée. Le deuxième paramètre concerne l'intensité moyenne maximale, élément essentiel dans l'étude des crues, dont l'estimation pose problème par suite du manque de données appropriées. La méthode proposée se veut classique et simple compte tenu des données disponibles dans toutes les stations météorologiques.

ISSN:0262-6667    

DOI:10.1080/02626669309492700

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The effects of acidic precipitation on stream chemistry were measured on an east-central Pennsylvania basin. When combined with flow and chemical mass balances, the data can help quantify hydrological source areas and their contributions to acidic storm hydrographs. For small storms on the well-buffered agricultural basin, small volumes of acidic precipitation falling directly on the stream surface react with more alkaline inflows from subsurface flow and surface runoff components to reduce streamflow pH temporarily by approximately one-half unit. During larger storms, the pH of surface runoff approaches that of precipitation, causing a relatively large acidic loading to the stream. However, this large input is buffered by a correspondingly larger subsurface flow component which results in stream pH reductions similar to those observed during the smaller events. Hydrological interpretations derived from a pH based mass balance are reinforced by a mass balance based on electrical conductivity and are consistent with the variable source area concept of basin hydrology.

ISSN:0262-6667    

DOI:10.1080/02626669309492701

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Conceptual semi-distributed hydrological models are developed for a limited consideration of spatial heterogeneity of hydrological characteristics within a river basin. This heterogeneity can be described by area distribution functions of hydrological characteristics which can be estimated in a most effective way by a Geographical Information System (GIS). It is shown how the application of a GIS can support the development and the calibration of a conceptual hydrological model. GIS information is used to establish the criteria for sub-division of the river basin and for estimation of model structures (especially for further horizontal divisions of each basin into more homogeneous parts). That information is also used for estimation of basin characteristics and their differences between sub-basins as a support for parameter calibration by optimization. The methodology presented can be used for the development of a model structure on an objective basis and for model calibration which considers the physical explanation of model parameters. The proposed method was successfully applied to a river basin within the Mosel basin (Germany).

ISSN:0262-6667    

DOI:10.1080/02626669309492702

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Basin characteristics are central to the regionalization of hydrological parameters and, in particular, runoff. Two examples are provided which demonstrate that Geographical Information Systems (GIS) can supply such characteristics at a national level, assuming that the necessary base data are available. These methods offer great potential for coordination and open new horizons for regional hydrology. The experience gained by the Swiss National Hydrological and Geological Survey is used to demonstrate the advantages which accrue from the flexibility of the application of GIS at regional and national levels.

ISSN:0262-6667    

DOI:10.1080/02626669309492703

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A methodology has been developed and applied to an eastern Nebraska, USA, case study to estimate the space-time distribution of daily precipitation under climate change. The approach is based on the analysis both of the type and of the Markov properties of atmospheric circulation patterns (CPs), and a stochastic linkage between daily (here 500 hPa) CP types and daily precipitation events. Historical data and General Circulation Model (GCM) output of daily CPs corresponding to 1 × CO2and 2 × CO2are considered. Time series of both local and regional precipitation corresponding to each of those cases were simulated and their statistical properties were compared. Under the dry continental climate of eastern Nebraska, a highly variable spatial response to climate change was obtained. Most of the local and the regional average precipitation values reflect, under 2 × CO2, a somewhat wetter and a more variable precipitation regime in eastern Nebraska. The sensitivity of the results to the GCM utilized should be considered.

ISSN:0262-6667    

DOI:10.1080/02626669309492704

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626669309492705

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626669309492706

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626669309492707

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

ISSN:0262-6667    

DOI:10.1080/02626669309492708

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor