ISSN:0197-9337    

DOI:10.1002/esp.3290160702

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractAccurate measures of global atmospheric energy balance collected since the International Geophysical Year (1957‐1958) show statistically significant relationships to regional monthly growing season discharge in east central France (also North Carolina, Texas, and Yucatan). The relationships are frequently curvilinear. Transfer functions can be calculated to reconstruct prehistoric and historic regional hydrological balance and project future effects. An astronomical climatology model is used to estimate past global energy balance. The projections appear to fit sediment, diatom, and pollen records. General circulation model estimates of greenhouse warming are used to drive future hydrological balance determination

ISSN:0197-9337    

DOI:10.1002/esp.3290160703

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractUsing runoff and climatic observations from 37 small watersheds in Hungary a regional climate‐runoff relationship has been established. This non‐linear relationship is a modification of Budiko's similar equation and can be used to estimate the effect of climate changes on long‐term average runoff. The degree of change in runoff depends not only on changes in precipitation and temperature, but also on the present climate characteristics. The regional relationship is verified only within a relatively narrow range of precipitation and temperature and this fact limits its use in climate impact assessment. Model calculations show that a relatively slight shift in climate, an increase in annual temperature by 0.5°C, and a decrease of annual rainfall by 0.08 mm d−1may lead to a decrease of runoff by 25‐30 per cent in small watersheds

ISSN:0197-9337    

DOI:10.1002/esp.3290160704

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThis paper presents a method, which has been recently developed in the Department of Agrometeorology of the Poznań Agricultural University, for estimating heat balance components based on standard meteorological data, plant development stage, and land‐use conditions. Estimates of latent heat flux components made it possible to obtain values of areal evapotranspiration and surface runoff. The method was applied in four catchment areas in Central Poland under present climatic conditions as well as under new, expected climatic conditions caused by an increase of ‘greenhouse gases’ in the atmosphere. Some changes in land use were also considered. The results show significant changes in the water balance when comparing present and future conditions of precipitation and evapotranspi

ISSN:0197-9337    

DOI:10.1002/esp.3290160705

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractA hydrological conceptual model developed by the Royal Meteorological Institute of Belgium has been run to assess the potential hydrological impacts of an hypothetical doubling of the atmospheric CO2concentration. The simulated scenarios were derived from the predictions of climatic change currently provided by General Circulation Models (GCMs).Three typical drainage basins in Belgium have been selected for assessing their common responses and bringing out possible specific behaviours attributable to catchment characteristics.The study dealt essentially with modifications of the streamflow and with alterations of the flood and low‐flow regimes.In catchments with prevailing surface flow the considered change in climate could induce:An increase in flood frequencies during the winter season together with a strengthening of the extreme river stages leading to greater flooding risks;A decrease in streamflow during the summer season and, as a corollary, increased risks of water pollution;Possible restraints, in summer and autumn, on water availability from local groundwater storages.In catchments with high infiltration rate and with strong aquifer the impact could be:An increase in groundwater storage, bringing about an increase in the base flow throughout the year, which in turn involves increased flood risks;A reduction of the number of low‐stage occurrences in summer, resulting in reduced river pollution;A possible increase in water availability from the aquif

ISSN:0197-9337    

DOI:10.1002/esp.3290160706

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractChanges in climatic conditions may have great impact on the distribution of available water in space and time. However the results of models that describe future climate conditions are still insufficient to be used in regional hydrological simulation studies.This article describes a first tentative estimation of the sensitivity of discharge of the river Rhine to two environmental changes. Firstly, to a change in snow covered area due to a rise of 4°C in winter temperature in the upland part (Alps) of the drainage area and, secondly, to a large land use change in the lowland area (Federal Republic of Germany/France).‘Worst case’ scenarios for discharge of the river Rhine under warmer conditions give a reduction of 10 percent for the summer discharge at Rees (Dutch/German border). The results of the estimations indicate that the reduction of the summer discharge in a warmer world could be la

ISSN:0197-9337    

DOI:10.1002/esp.3290160707

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractThe possible impact of climatic change on the water balance is analysed for the River Dommel and the Veluwe, an area drained by many very small brooks. A water balance is calculated for the winter and the summer period. With the help of four scenarios, based on GCMs, climate data from the dry year 1976 and land use scenarios the impact of climatic change and a possible superposed effect of acid precipitation is analysed. The results show that although the yearly changes in the water balance are small in some cases, in all cases the fluctuations in the water balance between winter and summer period increase. Changes in precipitation and evapotranspiration are multiplied in water storage and runoff. This will have consequences for water use planning and management.

ISSN:0197-9337    

DOI:10.1002/esp.3290160708

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractMonthly runoff and soil loss data of three fallow experimental plots are presented, comprising a summer and following winter season. The fallow plots were only tilled once, at the end of April. Summer runoff appeared to be controlled by rainfall intensity and conforms to the Horton model of overland flow generation. Winter runoff was primarily controlled by rainfall amount and conforms to the saturation or storage control model of runoff generation. Summer runoff volume was one fourth of winter runoff volume. Summer soil loss was twice as high as winter soil loss and was caused by high intensity, high energy rainfall. Winter soil loss was due to detachment limited erosion, caused by low intensity, low energy rainfall. Mean sediment concentration of winter runoff was one seventh of that of summer runoff. Implications for runoff and erosion of climatic change, involving increased rainfall amounts or intensities in summer or winter, are given.

ISSN:0197-9337    

DOI:10.1002/esp.3290160709

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractIn the northeastern part of Hungary near the township of Tokaj a landscape research project has been performed in a 9 km2area. The aim of this study is to examine the possibilities of expressing the climatic sensitivity of the given small landscape unit by analysing the capabilities of such a small sample area and synthésizing the data obtained. The landscape analysis consisted of field and laboratory measurements, theoretical calculations, analyses of maps, as well as the construction of thematic maps (on the scale of 1:10000) and cartograms.In view of climatic sensitivity four of the landscape factors were regarded as crucial: (1) the water budget of the soils, (2) the thickness of the soils and loose sediments, (3) insolation, and (4) land use. By synthesis of these factors a five‐grade climatic sensitivity map was produced. On the basis of the areal proportion of the different classes of sensitivity it was established that the study area is moderately sensitive to climate. Examination of the moisture content of soil clearly indicated different responses of the areas from the different sensitivity classes to changes in temperature and precipitation. The four main landscape factors selected proved to be useful in the rough delineation of the classes on the climatic sensitivity map. However, the use of the other landscape factors improved its accura

ISSN:0197-9337    

DOI:10.1002/esp.3290160710

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY

摘要:

AbstractPrevious work on stream channels in upland areas of Britain has demonstrated a close control over channel morphology and stability by the rate of coarse sediment supply from the hillslopes of the catchment. Streams fed by large amounts of coarse sediment develop unstable, wide, often braided channels, whereas those with limited coarse sediment supply develop stable, much narrower, often meandering channels. The sediment supply from hillslopes is controlled by thresholds of hillslope stability, storm event frequency, and the coupling between the hillslopes and the channel. Climatically‐induced changes in any of these three factors may have implications for channel morphology and stability. This paper examines these implications in British upland fluvial systems, with particular reference to the Howgill Fells, Cumbria, in the contexts of the adjustment of stream channels to sediment supply from erosional gully systems, and their response to and recovery from major flood event

ISSN:0197-9337    

DOI:10.1002/esp.3290160711

出版商:John Wiley&Sons, Ltd    

年代:1991

数据来源: WILEY