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1.
Marcel-M. CHARTIER 《水文科学杂志》2013,58(1):175-178
Abstract Existing models for generating synthetic daily streamflow data are unsuitable for reproducing the predominant features of daily flows, the rising and recession of flood flows, the peaks of the floods, the volume of the waves and the range. In this paper, a model is presented which is able to reproduce the important features of daily flows. In the model the measured record of daily data is assumed to be the output of a linear system. The input of the system consists of pulses, occurring on certain days. The pulses are convoluted with the system function in order to produce the output. The form of the system function depends on the magnitude of the output. First, the days on which pulses occur, the magnitude of pulses, and the form of the system function as a function of the system output, are determined. Subsequently, a model was developed for the generation of the pulses. The model consists of a combination of two processes. Using a Markov chain model, the sequence of dry and wet days (days with and without pulses) is generated. Thereafter, a pulse of certain magnitude is assigned to each wet day. A modified first-order autoregressive process is used to produce these correlated pulses. The random components of the pulses are taken from a transformed exponential distribution. The periodicity of the flows within the year is reproduced by using different model parameters for each month of the year. The model yields good results for small and medium size basins, especially as far as peak flows, the volume of the waves, and the range are concerned. A sequence of daily flows from at least 20 years is required for input data. 相似文献
2.
ABSTRACT From data obtained at stations set up in Chad, the Central African Republic and Congo-Brazzaville, stretching from the desert to the equatorial zone, it has been possible to compare measurements of evapotranspiration and of evaporation with results obtained by using the energy-balance method. Several difficulties arise in these comparisons since the scale of the measurements (small evaporating surfaces) is generally different from that of the climatic characteristics on which evaporation is dependent. After proposing a model to resolve this problem and fitting the empirical coefficients of Penman's formula, the author has applied this formula to some results derived for stations in Congo-Brazzaville; the potential evapotranspiration calculated in this way is in good agreement with water balance data. At these stations the evapotranspiration energy may be a constant percentage of global short-wave radiation. Finally, the energy-balance method has been used at Brazzaville to measure the actual evapotranspiration over grass during the dry season. The result is that actual and potential evapotranspiration were found to be closely related. These results indicate the importance of solar readiation in the field of hydrometeorology. 相似文献
3.
Gilbert CASTANY 《水文科学杂志》2013,58(4):5-17
Abstract Reserves stand for the gravific or releasable water volume stored up in an aquiferous level. It is possible to distinguish regulative, geological and potential reserves. Their calculation is necessitating the knowledge of hydrogeological structures and the determination of specific yield or coefficient of storage. The use of recession curves allows speedy valuations. 相似文献
4.
ABSTRACT The authors make a general survey of the methods of measuring soil permeability in the field, looking at them from the point of view of the hydrologist. In the first part they describe new equipment built by the ORSTOM Centre in Lome, Togo, to apply the Muntz method of vertical infiltration under constant head, equipment using a double cylinder and semi-automatic regulation of the discharge. In the second part, the authors make a mathematical analysis of the Porchet method of horizontal infiltration in a borehole full of water: they show that results may be interpreted even with heterogeneous (multi-layered) soils and that the calculations are simplified using a computer programme. In conclusion they deal with some results of measurements obtained by the two methods, and examine their accuracy and their correlation with the physical and hydrodynamics characteristics of the soils. 相似文献
5.
Abstract Results of a comprehensive synoptic-hydrological analysis of major flood events in the Negev (1964–2007) are presented. A low threshold for major flood data was set to be the 10-year recurrence interval of peak discharge and/or flood volume magnitude. Altogether, 75 major flood events, or 133 hydrometrically monitored floods, were extracted. These events were categorized according to synoptic oriented classes by verification of the paired databases of: (a) floods in the study area, and (b) synoptic systems over the Eastern Mediterranean. For the study area, two of the most frequent flood-generating synoptic systems are the autumn Red Sea Trough (RST), 31%, and winter cyclones, 49%. The entire RST series consists of 24 major flood events (55 floods). The synoptic definition was corroborated by analysing the specific form of flood hydrographs and the ratio of flood volume to peak discharge. Regional analysis shows increased contribution of RST events southwards from 30% to 90% with a respective decrease in the number of cyclone events. By comparing two 22-year sub-periods (1964–1985 and 1986–2007), a positive trend in the frequency and magnitudes of RST flood events is discerned. There is also an increased tendency for the occurrence of cyclone floods. Editor Z.W. Kundzewicz Citation Shentsis, I., Laronne J.B., and Alpert, P., 2012. Red Sea Trough flood events in the Negev, Israel (1964–2007). Hydrological Sciences Journal, 57 (1), 42–51. 相似文献
6.
Hamit N. PAMIR 《水文科学杂志》2013,58(4):40-49
Abstract Almost all runoff from the semiarid rangelands of the Southwestern United States results from intense convective storms of short duration. Depth-duration values for precipitation for this region that are developed through standard procedures may be misleading when used for runoff design. Various combinations of short bursts of rain can, and do, plot on average depth-duration curves, but such curves have little practical meaning for small watersheds (100 square miles or less). For design purposes for small watersheds, depths of precipitation for relatively short periods (15-30-60 minutes) for varying return periods and areas are needed. For runoff design for larger watersheds two probability estimates may be needed—the probability of storms of certain intensities and size falling on tributary watersheds of finite sizes, and the probability of storms developing over a multi-tributary system in such patterns as to produce important volumes and peaks of runoff. 相似文献
7.
8.
C. DIACONU 《水文科学杂志》2013,58(3):51-89
Abstract The study is based on the 121 answers to the international survey on ground water recharge published in I.A.S.H. bulletin n° 87. After generalities about the aims, benefits, type of devices, recharged aquifers and size of plants, are examined: —The infiltration devices (basins canals). —The injection devices (wells). —The economical aspects of realisations. Diverse statistical correlations are found, and regression formulas proposed, concerning: —Connections between permeability, size of devices, and the injection or infiltration rate. —Connection between the annual input and the capital invested. The synthesis of these datas conduct to results which may be useful to pepare new-projects of artificial recharge. 相似文献
9.
Gheorghe Demetrescu 《Studia Geophysica et Geodaetica》1958,2(3):293-295
Резюме Записи, относящиеся к глубоким землетрясениям, имевшим место с области Вранча, полученные на румынских станциях, свидетельствуют
о том, что между волнамиP иS существуют определенные импульсы, следующие друг за другом в довольно регулярных интервалах времени. Автор настоящей статьи
предлагает следующую интерпретацию.
Каждая волна, проходящая через поверхность разрыва, разделяется на две волны, из которой одна является продольной, а другая
поперечной, так что через каждый участок пути проходит продольная волна, обозначенная черезp, или волна поперечная, обозначенная черезs. При этих условиях и при предположении, что земная кора слагается лишь из гранитного и базальтового слоев, следует рассматривать
следующие волны:ppp≡P, pps, psp, pss, spp, sps, sss≡S. Эти волны могут быть использованы для определения толщины слоев земной коры.
Communication présentée à la 1ère Conférence séismologique de l’Académie Tchécosl. Sc. à Liblice, le 18 Mars 1957.
Adresse: Bucarest, rue Cuţitul de Argint 5, Roumanie. 相似文献
Communication présentée à la 1ère Conférence séismologique de l’Académie Tchécosl. Sc. à Liblice, le 18 Mars 1957.
Adresse: Bucarest, rue Cuţitul de Argint 5, Roumanie. 相似文献
10.
Claude VIGUIER 《水文科学杂志》2013,58(1):21-27
Abstract The necessary and sufficient conditions for non-zero phase shift and non-zero attenuation in linear flood routing can be derived from the continuity equation alone and are found to depend on the existence of an imaginary part in the expression for frequency or in the expression for wave number. It is shown that in linear flood routing the phase lag between flow rate and area of flow is directly related to the attenuation per unit wave length. The effects of using various forms of the momentum equation, in addition to the continuity equation, are exemplified by deriving analytical expressions in terms of the frequency, both for attenuation per unit channel length and for phase shift, for the kinematic wave, the general diffusion analogy, and the complete St. Venant equation. 相似文献
11.
B. I. KOUDÉLINE 《水文科学杂志》2013,58(3):25-35
Abstract Throughflow has been measured from three soil horizons on a 12 slope with impermeable, bedrock. Storm flow comes from the 10–45 cm horizon and is controlled by the upslope extent of saturated conditions. Base flow comes from the 45–75 cm horizon and is supplied by slow unsaturated flow from the whole soil mass to a small constant zone of saturation. Differences between input and output stream hydrographs over 270 metres of channel are attributed to throughflow and correlate well with measured values providing a basis for separating throughflow components from the stream hydrograph. Observed stream flows contain no overland flow or ground water flow components. The main basin flood peak is not generated within this control section of channel but is produced in the headwater zone (0.1 km2) by the faster runoff characteristics of the soils in that area and by topographic factors which lead to rapid channel extension. 相似文献
12.
le Prof. J. TRICART 《水文科学杂志》2013,58(4):75-84
Abstract The rivers Gard, Herault and Vidourle which go down very rapidly from the Cevennes into the Mediterranean sea, between very steep slopes, are particulary able to transport débris as a consequence of their very big floods. Nevertheless, during the floods of the autumn 1958, which were of a bi- or tricentenial frequency, only the loams, clays and sands were able to reach the sea during the flood. Shingle was transported in great quantities but only upon short distances, of no; more than 2 or 3 km. Even in such torrents, the transport of shingle is very long, and the greater part of the shingle actually present in the river bed was swept out from the foot of the slopes during the last cold period of the Quaternary, under periglacial conditions. The construction of a dam, at the Moulin de Bertrand in the Hérault valley, which does not allow the transit of shingle, did not result in the modifications in the conditions of transport of the pebbles downstream: the pebbles which are presently transported do not come from the upper valley, but are reworked from the accumulations built up in the bed before the construction of the dam. 相似文献
13.
We applied analysis AVO with partial stacking to an onshore gas field in order to detect gas at the top of the Ciénaga de Oro formation (FCO), by using seismic gathers of the Güepajé-3D project. The technique was supported by petrophysical analysis of the Ayombe-1 well.The sensitivity of seismic response to changes in the saturating fluid was evaluated by fluid substitution technique in an interval of the Ayombe-1 well. As a result, a class I AVO anomaly at the top of the FCO was observed, even though the gas and water responses were similar. After applying AVO with partial stack technique at the top of FCO, AVO class I anomalies were observed in the Ayombe-1 and Güepajé-1 gas wells and none in the dry Güepajé-3 well. In spite of being reported with gas, the results in the Güepajé-2 well indicated any to an incipient class I anomaly related to a weak seismic response associated to gas.When the technique was applied to the seismic volume of the Güepajé-3D Project, a map of the direct gas indicator was obtained. The map shows a high correlation with the structural surface at top of FCO. Lithic factors such as compaction, cementation and carbonate overlaying the FCO and variable thickness of partial and full saturated layers, may cause anomalies in zones unlikely to contain gas. 相似文献
14.
Abstract The problem of non-steady flow of water in a soil-plant system can be described by adding a sink term to the continuity equation for soil water flow. In this paper the sink term is defined in two different ways. Firstly it is considered to be dependent on the hydraulic conductivity of the soil, on the difference in pressure head between the soil and the root-soil interface and some root effectiveness function. Secondly the sink is taken to be a prescribed function of the soil water content. The partial differential equation applying to the first problem is solved by both a finite difference (FD 1) and a finite element (FE 1) technique, that applying to the second problem by a finite difference approach (FD 2). The purpose of this paper is to verify the numerical models against field measurements, to compare the results obtained by the three numerical methods and to show how the finite element method can be applied to complex but realistic two-dimensional flow situations. Two examples are given. The first concerns one-dimensional flow and it compares numerical results with those obtained experimentally in the field from water balance studies on red cabbage (Brassica oleracea L. ‘Rode Herfst’) grown on a clay soil in the presence of a water table. The second example describes two-dimensional flow in a complex field situation in the Netherlands where flow takes place under cropped field conditions through five anisotropic layers. Water is supplied to the system by infiltration from two unlined ditches and is withdrawn from the system by evapotranspiration and by leakage to an underlying pumped aquifer. 相似文献
15.
Maurice Striffling 《Pure and Applied Geophysics》1950,17(3-4):130-135
Summary The position of the very important climatic limit, definited byBenevent, which separates the humid climate of north Alps and the dry climate of south Alps, is first described. The method used for synoptic study of alpine precipitations is then exposed: it consists in plotting for every day on a great scale chart the amounts of rain measured in the alpine rain-jauge stations and in comparing this result with the isohypses charts at the 700, 500 and 300 mb levels. 相似文献
16.
G. Jobert 《Pure and Applied Geophysics》1959,43(1):75-82
Summary The scheme of a seism caused by the slipping of a transcurrent fault is examined and the law of the variation of the seismic superficial displacement v/s distance to the fault is given, assuming that no extra stress is produced at the base of the broken layer. Taking a simple example for the preseismical strain, it is possible to find an order of magnitude of the extent of the fault in depth. An application to the San Francisco seism of 1906 gives a depth of about 13 km.
Resumo Oni ekzamenas skemon de sisma ekmovo e fendego transkuranta kaj oni donas la leon de la supraa ekmovo kiel funkcio de la distanco al la fendego, en la hipotezo ke tiu movo ne produktas novan streon e la bazo de la fendita tavolo. Prenante simplan ekzemplon por la antaùsisma deformio oni povas determini proksimuman amplekson de la profundeco atingita de la fendo. Aplikado al la sismo de San Francisco de 1906 donas por la profundeco cirkaùe 13 km.相似文献
17.
Résumé On compare, en premier lieu, les crochets magnétiques donnés par le Bulletin de l'I.A.G.A. avec les crochets visibler sur les enregistrements de Tamanrasset entre 1949 et 1957. 33% des crochets sont retrouvés, et on étudie leur fréquence. Celle-ci suit le cycle solaire, esdt minimum l'hiver et plus élevéc l'après-midi que le matin. L'obíssance à la loi deMcNish ne semble pas prouvéc. L'amplitude la plus probable est de 7 . — On étudie ensuite des phénomènes ressemblant aux crochets (faux crochets) et caractérisés par une allure bien définie des dérivéesdH/dt etdD/dt. Leur fréquence ne suit pas le cycle solaire, est minimum à l'équinoxe et uniforme dans le cours de la journée. L'amplitude la plus probable est de 7 à 10 , et la durée de développement de l'ordre de 5 minutes. La direction du vecteur perturbation est NNW ou SSE, avec prédominance du SSE, ce qui correspond dans l'ionosphère à un courant WSW-ENE. L'existence des faux crochets peut expliquer certaines confusions dans l'identification des crochets.
Summary First of all, we compare the magnetic crochets given by the I.A.G.A.-Bulletin with the crochets we can see on Tamanrasset records between 1949 and 1957. We find out 33% of these crochets and we study their frequency. It follows the solar cycle, it is minimum during winter and greater in the afternoon than in the morning. Obedience toMcNish law does not seem to be proved. The more probable amplitude is 7 . — Then we study phenomena looking like crochets (false crochets) which are caracterised by a well definite feature ofdH/dt anddD/dt. Their frequency does not follow solar cycle, it is minimum et equinox and level during the course of the day. The more probable amplitude is from 7 to 10 , and the development plasts about 5 minutes. The direction of disturbance vector is NNW or SSE, with predominance of SSE, which sould correspond to a WSW-ENE stream in the inosophere. The existence of false crochets may explain some confusions when we identify crochets.相似文献
18.
Abstract The Rhone changed progressively, from SE to NW, his underflow and his upperflow, advancing together in that direction. The study of the evolution of erosion show the Rize is a relic of the ancient flow. The like processus is proper to many rivers. 相似文献
19.