共查询到20条相似文献,搜索用时 15 毫秒
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ABSTRACT The purpose of an hydrometric network is to obtain data giving answers to problems raised by the use of water. The methodology suggested in this paper is essentially based on the regional identification of the actual and potential uses of water, on the estimate of the intensity of their use and on the determination of the hydrological characteristics related to this demand. The level of accuracy required for these characteristics is an important feature in the rationalization procedure. The various types of stations are defined according to the purpose of their use and the network considered is on a dynamic basis depending on the evolution of uses. The major results obtained for Quebec by the application of this method are described. 相似文献
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BORIS SEVRUK 《水文科学杂志》2013,58(2):231-236
ABSTRACT The evaporation losses from the container of an old galvanized Hellmann gauge, 7·1 cm2 aperture area, were five times greater than the losses from the container of a new gauge, 1·8 cm2 aperture area, of almost the same grey colour. The maximum evaporation from the old gauge amounted to 0·75 mm per day. The same evaporation losses in the Baye of Montreux basin over a period of 10 years from April to September amounted to 0·09 mm per measurement or to 0·7 per cent of the precipitation catch. There is a relationship between the monthly percentage evaporation losses and the ratio of evaporation time and rainfall duration (r = 0·803). 相似文献
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《水文科学杂志》2013,58(2):362-366
Abstract Most commonly used biochemical oxygen demand (BOD) and dissolved oxygen (DO) models have been tested for their applicability in the River Kali, which is one of the most polluted rivers in India. A total of 732 field data sets were generated during field survey from March 1999 to February 2000. The modelling of BOD and DO in the River Kali involves derivation and solution of the governing equations that describe concentration change with time and space brought on by advective, decay, settling and loading functions. However, due to continuous discharges (e.g. from wastewater treatment plants) and steady-state flow conditions in the River Kali, the dispersion effects are found to be insignificant. In the analysis, the model parameters used in BOD-DO models were optimized using the Newton-Raphson technique and the performance of different models was evaluated using correlation statistics (r 2) and error estimation, viz. standard error (SE) and mean multiplicative error (MME). The results indicate that the BOD-DO models developed after Camp (1963) yielded the best agreement with the observed values as compared with several other approaches. 相似文献
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《水文科学杂志》2013,58(3):481-486
Abstract Explicit algebraic expressions of influence coefficients of an aquifer system are addressed. The methodology is straightforwardly exemplified using a one-dimensional (1D) semi-confined homogeneous aquifer model. It consists of the integration of the governing equation from two different viewpoints. On the one hand, the analytical solution to the governing equation is presented under an integral form involving the appropriate Green function. On the other hand, equations resulting from a finite difference discretization are processed to deduce a fully explicit algebraic expression of the nodal hydraulic head. This latter, arranged after the previously developed continuum solution, helps with deriving an explicit algebraic expression of influence coefficients corresponding to the studied aquifer model. Finally, the study is extended to an inhomogeneous aquifer model. 相似文献
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应用文献计量方法,对《湖泊科学》1989 ̄1995年出版的20期所刊243篇论文进行统计分析,包括论文分类统计、作者分析、基金论文统计分析等。在分析基础上阐述湖泊科学发展现状以及为期刊编辑、文献工作者提供一个量化的衡量工作的依据。 相似文献
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JAROSLAV BALEK 《水文科学杂志》2013,58(2):69-75
ABSTRACT This article has been abstracted from the study carried out during 1960–61 on Albania rivers. and employs data observed by Hydrometeorological Institute of Albania as well as author's field investigations. Todate very little published information on the natural resources of Albania is available. Presented article should provide the part of the missing hydrometeorologic data in South-eastern Europe. 相似文献
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Abstract The analysis of the exchanges of vapour and heat above a small water table, situated in the middle of a more or less dry region, leads them to be expressed in function of the thermic and hydric changes of the environment, by which the measured, screened data are influenced. This analysis allows us,—among other results,—to observe the variation from simple to the double of the evaporation. This has come to evidence already in cases when the evaporating surface diminishes. The application was carried out under two exceedingly different climates: in a Sahelian zone, on a pan type “Colorado”, situated in the middle of a bare surface, with very poor evaporation; and in an equatorial zone, on a “Colorado” pan, in the center of a humid zone, where the vegetation could dispose of water in sufficient quantity. The results confirm the hypothesis set up, and allow us to take into consideration the use of the pans corrected data for expressing the potential evaporation. 相似文献