PUBLICATIONS DE L'ASSOCIATION INTERNATIONALE DES SCIENCES HYDROLOGIQUES     

J. P. VILLENEUVE  B. BOBÉE  H. ST-MARTIN  M. SLIVITZKY 《水文科学杂志》2013,58(4):459-463

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   

Purification of Drinking Water (Municipal Water Supply) by Activated Charcoal,Potassium Permanganate and Silica Gel Beds Vis a vis to Bleaching Powder and Its Effects on Fish Life     

Smt. Lakshmi  A. K. Srivastava  A. N. Mishra  K. N. Pandey 《洁净——土壤、空气、水》1989,17(3):335-339

A novel method has been developed to purify the municipal water. A pH of 7.05 has been achieved, which is suitable for the drinking purpose. Heavy metal, Pb²+ ions, have been removed to the extent of 0.074 mg/l. This purified water also saves the life of fishes. At the same time the use of bleaching powder in purifying municipal water has been avoided due to its hazardous effect even on fishes.  相似文献   

Bioestimation: A new method for the control of water self-purification process and its comparison with bioindication     

O. G. Nikitina  V. N. Maksimov  N. G. Bulgakov  N. E. Nikitin 《Water Resources》2009,36(4):453-458

A new line in the studies of water bodies is proposed: the assessment and correction of the process of biotic purification of water (biological treatment and self-purification). The proposed approach is based on a principally new hydrobiological method of monitoring and control of water quality formation process—bioestimation. The principal novelty of bioestimation is due to the fact that it controls not the quality of the aquatic medium, but the object that has not been controlled before—water purification process and organic matter transformations in the process of vital activity of saprotrophic bacteria. Three critical groups of factors were found to govern the activity of these bacteria: the dynamic characteristics of the aquatic environment; the load on destructors in terms of organic matter; and the impact of substances, which are atypical of natural water and most often are discharged in it with industrial wastes. A group of indicator microorganisms—bioestimators—is chosen for each group of factors. The population size of such estimators can be used to identify and next eliminate the disturbing factor. The bioestimators are not species but ecological groups of microorganisms, commonly inhabiting any waters, either salt or fresh. Bioestimation also helps to identify disturbances in water purification process even in the cases where analyses of aquatic environment quality do not signal alarm. The proposed method is described and its major distinctions from the well-known hydrobiological method (bioindication in its original, saprobiological meaning) are demonstrated.  相似文献   

The Tragedy of the Karama Dam Project/Jordan     

Elias Salameh 《洁净——土壤、空气、水》2004,32(3):249-258

The Karama Dam, with a capacity of 55 Mio m³, was constructed in 1995 on Wadi Mallaha in the Jordan Valley area in order to store water for irrigational uses. The dam was constructed in spite of experts' warnings that this dam geologically, hydrogeologically, seismically, and from the points of view of salinity of its water, its management and the water resources to fill it is totally irrelevant, and that the dam will fail to fulfill its purposes. Now after 9 years of its construction the dam fails to collect water because there are no sources available to fill it. The water the farmers were deprived of to partially fill the dam to demonstrate its success became in the dam reservoir highly saline (20 000 μS/cm). Reservoir bottom collapses due to dissolution of salts took place and large water amounts were lost to the underground. Not a single drop of water from the dam has been of any use for any purpose until now. Equipment to pump water for irrigational uses has been corroding, and the government is paying the depreciation, capital, and running cost of a fiasco project.  相似文献   

采用倒置显微镜法定量浮游植物的数据稳定性   总被引：2，自引：0，他引：2  

牛海玉  肖利娟  韩博平 《湖泊科学》2016,28(1):141-148

浮游植物种类组成细胞密度或生物量的现存量反映其在水生生态系统的结构与功能,准确地对水体中浮游植物进行定量是水质评价和生态功能分析的基础.针对目前国际上推荐使用的倒置显微镜法(即Utermhl计数法),通过采集处于不同营养状态和水体条件(水库和实验围隔)中的浮游植物,分析样品的显微计数量、水体营养状态对浮游植物密度和多样性等指标稳定性的影响,同时比较了多个水体中同一采样点的重复(或平行)样品之间浮游植物定量数据的差别,从而对倒置显微镜法进行较为系统的评估.结果表明,基于浮游植物的显微镜计数效率与定量数据稳定性的综合考虑,选择计数400个个体即可基本保证定量数据的稳定性;在依赖生物量或稀有种进行水质评价时,处于不同营养水平的水体均需要增加样品的平行数来提高定量数据的可靠性,贫营养型水体中单个采样的重复或平行样品更为必要;两种定量方法所得群落数据计算的辛普森指数无显著差异,说明两种方法所获得结果均能反映浮游植多样性;通过样品浓缩法和倒置显微镜法所获得的浮游植物生物量和细胞密度均具有显著差异,因样品浓缩法在样品处理过程中造成浮游植物损失,使通过样品浓缩法所得的浮游植物群落生物量及细胞密度偏小;相比浓缩法,倒置显微镜法沉淀浓缩的水样体积小,样品处理和计数耗时短,更适宜用于应急监测.  相似文献   

A fast direct solution method for nonlinear equations in an analytic element model     

Haitjema HM 《Ground water》2006,44(1):102-105

The analytic element method, like the boundary integral equation method, gives rise to a system of equations with a fully populated coefficient matrix. For simple problems, these systems of equations are linear, and a direct solution method, such as Gauss elimination, offers the most efficient solution strategy. However, more realistic models of regional ground water flow involve nonlinear equations, particularly when including surface water and ground water interactions. The problem may still be solved by use of Gauss elimination, but it requires an iterative procedure with a reconstruction and decomposition of the coefficient matrix at every iteration step. The nonlinearities manifest themselves as changes in individual matrix coefficients and the elimination (or reintroduction) of several equations between one iteration and the other. The repeated matrix reconstruction and decomposition is computationally intense and may be avoided by use of the Sherman-Morrison formula, which can be used to modify the original solution in accordance with (small) changes in the coefficient matrix. The computational efficiency of the Sherman-Morrison formula decreases with increasing numbers of equations to be modified. In view of this, the Sherman-Morrison formula is only used to remove equations from the original set of equations, while treating all other nonlinearities by use of an iterative refinement procedure.  相似文献   

A genetic algorithm for filter design to enhance features in seismic images     

M.G. Orozco‐del‐Castillo  C. Ortiz‐Alemán  J. Urrutia‐Fucugauchi  R. Martin  A. Rodriguez‐Castellanos  P.E. Villaseñor‐Rojas 《Geophysical Prospecting》2014,62(2):210-222

We present a novel method to enhance seismic data for manual and automatic interpretation. We use a genetic algorithm to optimize a kernel that, when convolved with the seismic image, appears to enhance the internal characteristics of salt bodies and the sub‐salt stratigraphy. The performance of the genetic algorithm was validated by the use of test images prior to its application on the seismic data. We present the evolution of the resulting kernel and its convolved image. This image was analysed by a seismic interpreter, highlighting possible advantages over the original one. The effects of the kernel were also subject to an automatic interpretation technique based on principal component analysis. Statistical comparison of these results with those from the original image, by means of the Mann‐Whitney U‐test, proved the convolved image to be more appropriate for automatic interpretation.  相似文献   

Remotely sensed estimation of water discharge into the rapidly dwindling Dead Sea     

D. Vachtman  J.B. Laronne 《水文科学杂志》2013,58(8):1593-1605

Abstract

The Dead Sea is shrinking as its water level drops at the alarming rate of about 1 m year^-1. The Dead Sea is important to the economies of Israel and Jordan due to the extracted minerals (primarily potassium, also magnesium and bromide). It is also central to regional tourism. It is the lowest place on Earth and its endorheic, saline basin attracts international research in various disciplines. Additional to the Lower Jordan River, the discharge of which has been decreased to a small fraction of its original value, fresh to brackish springs are the main source of water to the rapidly dwindling Dead Sea. Although the existence of these springs has been known for decades, until recently estimates of spring water discharge into the Dead Sea were scarce. In this study, we developed a methodology of water discharge estimation for channels incising into a lacustrine bed using remotely sensed data and a single hydraulic geometry variable, water-surface width. Based on calibration of over 400 in situ measurements and simultaneous hydrometric data from aerial images, width–discharge rating curves were established, tested, and found suitable (r² = 0.92, p = 0.001) for the estimation of water discharge, with ±5% uncertainty. Furthermore, we used these relationships to estimate retrospectively the temporal changes in water discharge of seven main channels traceable in historical aerial images. The reconstructed trend reveals a major (63%) reduction in average freshwater inflow between 1990 and 2006. Our results maximize the use of water-surface width information from aerial imagery, and suggest applicability to areas experiencing rapid exposure of sea/lake bed and consequent access difficulties in in situ discharge monitoring.