WATER QUALITY MONITORING NETWORK DESIGN: A PROBLEM OF MULTI‐OBJECTIVE DECISION MAKING¹

Abstract

Hydrologic data network design i8 a fairly complicated problem where questions as to the number of gages required, time frequencies to be selected, and benefits/costs of monitoring still remain unresolved. These issues are intensified in case of water quality variables as they are more error-prone, costly, and time consuming to sample. The basic difficulty underlying the design and evaluation of monitoring systems is the lack of an objective criterion to assess: (a) the efficiency, and (b) cost-effectiveness of a network. A statistical procedure based on the entropy principle of information theory is proposed to address the evaluation of both factors. Efficiency is measured quantitatively in terms of the information produced by a network. Similarly, benefits of monitoring are described by informative measures for an objective evaluation of cost-effectiveness. The study presented demonstrates the applicability of the entropy method in assessing the efficiency and the benefits of an existing water quality monitoring network. The method is applied for temporal and spatial features of monitoring, handled as both separate and combined problems. The results are shown in the case of the highly polluted Porsuk River in Turkey. The strengths and shortcomings of the proposed methodology are discussed, with recommendations for future research on the application of the entropy principle in network design. (KEY TERMS: water quality monitoring; network design; network efficiency; benefits/costs of monitoring, information; entropy.)

An Analysis of the Value of Additional Information Provided by Water Quality Measurement Network

“…Taking the equations used to express the value of additional information described in Equation (6), the error costs given in Equation (9), and the inaccuracy, Equation (3), of 1%, 5% and 10%, Figure 1 shows the evolution of the value of information according to the priori probability that the environment is sensitive to nutrients. We can see in Figure 1 that when p, the a priori occurrence of eutrophication, is low, the value of information is higher when the damage is greater.…”

Optimal Expansion of Water Quality Monitoring Network by Fuzzy Optimization Approach

“…Earlier studies in the 1990s focused on fundamental principles and applications in siting the water quality monitoring stations (Smith and McBride, 1990;Loftis et al, 1991;Esterby et al, 1992). Later on, in an attempt to assess systematic issues relevant to network design, more studies applied the techniques of integer programming (Hudak et al, 1995), statistical assessment (Hussain et al, 1995), multi-objective programming (Harmancioglu and Alpaslan, 1992;Cieniawski et al, 1995), and Kriging theory (Lo et al, 1996). A broader sense of applications was gained from the discussions of design principles of monitoring network (Dixon and Chiswell, 1996) and the guidelines related to biological impact assessment in the rivers (Timmerman et al, 1997).…”

Multicriterion decision analysis approach to assess the utility of watershed modeling for management decisions

“…This is a useful technique, especially when the impacts cannot be readily estimated in monetary terms [Belton and Stewart, 2003]. The MCDA technique has been applied to an array of problems in water resources, including water transfer options and reservoir operation [Stansbury et al, 1991;Ko et al, 1992;Harboe, 1992;Bogardi and Duckstein, 1992;Roy et al, 1992;Tecle, 1992;Srdjevic et al, 2004;Raju and Duckstein, 2004;Fassio et al, 2005], design of monitoring networks [Woldt and Bogardi, 1992;Harmancioglu and Alpaslan, 1992], various applications in forestry [Huth et Lasch et al, 2005], wastewater treatment alternatives [Tecle et al, 1988;Khalil et al, 2005], and computer-assisted tools for negotiation of water resources conflicts [Thiessen and Loucks, 1992].…”