Basic approaches in design of water quality monitoring networks

Proceedings of the 17th Biennial Conference of the International Association on Water Quality. Part 8 -- 24 July 1994 through 30 July 1994 -- Budapest, Hung -- 42365The general trend in water quality management has been to gather and use information on water quality variables for purposes of planning, design, and operation of water resources systems and wastewater treatment However, the growing concern for environmental quality has given rise to a new trend in respect of the impact of water quality variables on human health and life conditions. Thus, there is the need for better understanding of how water quality processes evolve both in time and space under natural and man-made conditions. This accentuates the need for more efficient practices of monitoring to satisfy the objectives of water quality management plans. Upon this need, the adequacy of collected water quality data and the performance of existing monitoring networks have been seriously evaluated within the last decade. Problems observed in available data and shortcomings of current networks have led researchers to focus more critically on design procedures used. This paper examines the state-of-the-art in design of water quality monitoring networks. Available design procedures are discussed with respect to three basic features of a network: selection of sampling sites, sampling frequencies, and variables to be sampled. In conclusion, recommendations are presented for improvement of current approaches to the design problem.The general trend in water quality management has been to gather and use information on water quality variables for purposes of planning, design, and operation of water resources systems and wastewater treatment. However, the growing concern for environmental quality has given rise to a new trend in respect of the impact of water quality variables on human health and life conditions. Thus, there is the need for better understanding of how water quality processes evolve both in time and space under natural and man-made conditions. This accentuates the need for more efficient practices of monitoring to satisfy the objectives of water quality management plans. Upon this need, the adequacy of collected water quality data and the performance of existing monitoring networks have been seriously evaluated within the last decade. Problems observed in available data and shortcomings of current networks have led researchers to focus more critically on design procedures used. This paper examines the state-of-the-art in design of water quality monitoring networks. Available design procedures are discussed with respect to three basic features of a network: selection of sampling sites, sampling frequencies, and variables to be sampled. In conclusion, recommendations are presented for improvement of current approaches to the design problem

Optimisation methods applied to river basin management

This paper aims to present the methods used for water management in a test basin within the scope of the EU FP6-sponsored OPTIMA project. The study uses a simulation based water resources planning and optimisation system, established through a web-based client-server implementation to support distributed use and easy access for multi-criteria optimisation and decision support. © 2006 Civil-Comp Press

Regional flood frequency analysis using L-moments

Regional flood frequency analysis was performed using L-moments. The analysis uses annual maximum flood data observed at a desired project location or streamgaging station to estimate flood quantiles. Regional flood frequency analysis involves four stages: screening of the data, identification of homogeneous regions, choice of a regional frequency distribution, and estimation of the regional frequency distribution. Gauging sites of study basins were found to be homogeneous after redefinition of regions

Application of the entropy concept in design of water quality monitoring networks

The study proposes an information-based perspective for the technical design of a network with two basic objectives: maximization of information produced by the network and minimization of accruing costs. Both are evaluated by the entropy principle which provides an information based statistical measure to evaluate the efficiency and cost-effectiveness of a monitoring network, considered here as an "information system'. The entropy concept serves four main objectives of network design: temporal design, spatial design, combined temporal/spatial design, selection of variables and determination of sampling duration. -from Author

Versatile uses of the entropy concept in water resources

Informational entropy is used within a probabilistic context to define uncertainties in hydrologic variables, hydrologic systems and their models, and parameters of probability distribution functions. The paper discusses the versatile uses of informational entropy in water resources, summarizing the progress obtained so far in developing the concept into a widely accepted technique. Besides the already covered areas of application, new fields where entropy can be used effectively are proposed to cover basically problems in environmental engineering. In view of current research results, the merits and limitations using entropy in water resources engineering problems are discussed, followed by the conclusion that there is a definite need for further investigations so that entropy becomes a principal technique in hydrology and water resources. -from Author

The role of the entropy concept in design and evaluation of water quality monitoring networks

Existing water quality networks suffer from a lack of compatibility between collected data and water quality management objectives, resulting in "data-rich but information-poor' monitoring practices. Other problems with the networks pertain to selection of variables to be observed, selection of sampling frequencies, selection of sampling sites, duration of monitoring of certain variables at certain sites, and reliability of collected data. A methodology is proposed for designing an efficient and cost-effective water quality monitoring network. The methodology is based on the entropy concept which permits alleviation of shortcomings of existing networks. -from Author

Assessment of information related to floods

Regional flood analysis techniques were used to improve the available information about floods either at a point or at all points of interest in a region. The entropy principle was employed as a convenient statistical tool in evaluating regional flood information and uncertainty. It was observed that reduction of uncertainty or increase in information about flood characteristics within a basin is the most crucial step towards coping with flood