Water Quality Control in Watercourses

Different approaches to studying hierarchical problems are compared with the use of a two-stage dynamic model of water quality control in the case of point pollution sources. Variations in pollutant concentrations in a watercourse are described by partial differential equations. The study embraces the cases of a single and multiple point pollution sources and different types of pollutants.     

Water Quality Control in Impoundments

This report on a seminar of the Water Research Institute in Prague deals with the methodological aspects of the measurement and evaluation of data for the water quality in impoundments in the CSSR mainly with respect to: the assessment of external causes, especially of anthropogenic influences in the catchment area, on the water quality (eutrophication, humic substances, trace elements), of the multi-purpose utilization of impoundments, the classification and development of the water quality in impoundments, the intensified utilization of impoundments as well as the influences of sediments and the effect of piscicultural measures on the water quality. The paper is subdivided into the following chapters: system of measurement network and analysis, stratification number of samples, number of the criteria to be investigated, extreme periods of discharge, multi-purpose utilization of impoundments, eutrophication, fish stocks.     

Long-Term Prediction of Water Quality in Marine Water Areas

Random walk approach is used to develop a model for long-term prediction of water quality in shallow marine waters. The model allows one to simulate variations in hydrological situations, reactive solutes, interaction between solutes and liquid and solid boundaries. The model application is illustrated by calculations for Amur Bay. Calculations using the long-term prediction model has not found a stationary state in the pollution level. The velocities of seaward motion of pollution front and the rates of increase in the concentration of a nonreactive solute are given.     

Modeling Ground Water Quality Sampling Decisions

Questions such as what, where, when, and how often to sample play a central role in the development of monitoring strategies. Limited resources will not permit sampling for many contaminants at the same frequency at all well sites. Therefore, a resource allocation strategy is necessary to arrive at answers for the preceding types of questions. Such a strategy for a ground water quality monitoring program is formulated as an integer programming model (an optimization model). The model will be of use in the process of deciding what constituents to sample and where to sample them so as to maximize a given objective, subject to a set of budget, sampling, and regulatory constraints. The maximization objective in the model is defined as a weighted function of population exposure to a scaled measure of observed chemical concentrations. The sampling constraints are based on the observed variability of contaminants in the aquifer, needed precision in estimates, a chosen level of significance, the available budget for implementing the program, and selected regulatory constraints. The model is tested with field data obtained for 10 selected constituents from more than 650 wells in the Cambrian-Ordovician aquifer in Iowa. Results from two alternative formulations of the model are compared, analyzed, and discussed. Further avenues for research are briefly outlined.     

Rotifers as Indicators of Water Quality

A comprehensive survey of the literature on the use of rotifers as bio-indicators water quality has been made in this article. Brachionus angularis, Trichocerca cylindrica, Polyurthra euryptera, Pompholyx sulcata, Rotaria rotatoria, Filinia longiseta have been designated as indicators of heavy pollution (Eutrophy). Ascomorpha ovalis, Asplanchna herricki, Synchaeta grandis, Ploesoma hudsoni, Anuraeopsis fissa, Monostyla bulla and M. hamata are indicators of fresh and clean waters (Oligotrophy) while a variety of rotifers including Brachionus, Keratella spec, are inhabitants of moderately clean (mesotrophy) waters. However, more and more knowledge regarding morphological variations and physiological conditions of rotifers should be studied and then they can be used as better indicators of environmental quality.     

The Challenge of Ground Water Quality Monitoring

"Valuable information pertaining to contaminant sources, contaminants, and ground water quality was derived using the state-supplied data."     

Optimal Allocation of Water Resources Considering Water Quality and the Absorbing Pollution Capacity of Water

Water Resources - A water resource allocation model coupling quantity and quality is a topic of concern in China. The water resources supply modelling is set up according to the water quality, and...     

Satellite Imagery in Distinguishing the Water Quality

On the basis of selected literature of 1973…1987 a surrey is given of the problem of the remote sensing of waters. There has to be distinguished between the passive methods of photography in different wavelength ranges of radiation, the direct radiometric measurement as well as scanning in the ranges of visible, near infrared and thermal radiation and the active methods of radar and lidar, the analogue of the radar with laser pulses. For the water quality, especially measurements concerning the optical conditions near the water surface, transparency and turbidity, chlorophyll content, water blooms and stocks of macrophytes, water temperature, especially during thermal loading of waters are possible. Examples of the analysis of imagery from the satellites ERTS-1, Landsat-2, TIROS-N and NOAA-6 as well as Nimbus 7 and of their computer-aided, expensive analysis are discussed. At present, limiting factors are mainly the size of the picture elements (pixels) of the scanners of 80 × 80 or 30 × 30 m, in general. At present, they can be applied only to very large waters as well as the oceans and coastal areas.     

阳澄湖若干水质资料的分析与评价

根据１９９４年５月于阳澄湖湖区７个采样点水质分析结果,表明湖水中矿化度较高,硬度较大,主要离子以ＨＣＯ３＾－,Ｎａ＾＋为主,分别占阴阳离子摩尔总数的５７．６１％、６３．９％。湖水水型西湖、中湖为重碳酸盐钠组Ⅰ型,东湖为重碳酸盐钠组Ⅱ型水。湖水中Ｎ、Ｐ营养元素丰富,ＮＨ３－Ｎ、ＮＯ２－Ｎ指标与７０年代相比明显增高,表明水体已曹室不程度地轻污染。     

Ground Water Quality Monitaring: The Arkansas Approach

Monitoring ground water quality on a statewide basis is a challenge being faced by a number of state and federal agencies involved with water quality. Many of these agencies have come forth with publications that are of some use to those who are engaged in developing monitoring networks. A review of this literature could save those involved much time and money by providing insight into what can be accomplished and/or avoided. Ultimately, each monitoring system has to be designed to meet the purposes and conditions for which it is created, no two situations ever being exactly alike. However, there are approaches and methods that can be borrowed and profitably utilized where both the problems confronted and the geology in which they are found are similar. It was the attempt to resolve these two conflicting tenets, situational uniqueness and methodological transferability, that impelled the state of Arkansas to develop the prototype approach that is to be described, along with some of the more important documents that were of use in the development of that approach.
Figure I highlights the main tenets of the prototype approach and Figure II locates each prototype within the state of Arkansas.