Stormwater July/August 2012 : Page 52

GUEST EDITORIAL Continued data to estimate basic characteristics and parameters of the impacts. The most com-mon parameters employed to describe impacts during impact prediction and decision-making include classes of project impacts (shown in Box 2) and character-istics of project impacts (Box 3) (Lohani et al. 1997, Sadler and McCabe 2002, Fisher and Stoughton 2003). The estimation of these characteris-tics and parameters can be seen as a prediction of what would be the outcome of the aspect. There are many methods and techniques to predict and forecast the basic impacts’ characteristics, rang-ing from simple techniques (e.g., intuition, comparisons with similar events and proj-ects, and checklists and matrices; in all of these techniques professional judgment must be employed) to experimental meth-ods (physical models, ﬁ eld or laboratory experiments), mathematical models, and survey techniques (Munn 1979; Canter 1997a). One simple way to classify predic-tion methods is to divide them into quan-titative, qualitative, and visual methods (Therivel 2006). For water-quality monitoring (WQM) projects, the project complexity, size, and objectives will determine which method-ology may be the most effective and efﬁ -cient to determine or estimate the impacts’ characteristics. However, if one consid-ers that most WQM projects operate with constraints in personnel, time, and money, the application of qualitative methods is a good alternative to obtain a quick and fairly decent characterization of most of the im-pacts. In addition • Professional or expert judgment, previous experience, and scientiﬁ c knowledge are commonly used in the decision-making process of WQM as well as to assess speciﬁ c undesirable outcomes (Ongley 2000, USEPA 2002, Miles 2009). • Qualitative methods can be used when there is little quantitative information, and the time and effort to implement qualitative methods is relative small compared to computer-based quan-titative methods (Norton et al. 1988). In addition, professional judgment is generally employed when the data are conﬂ icting and ambiguous or when assumptions must be developed to ﬁ ll data gaps (USEPA 1998b). • Qualitative methods that are consid-52 July/August 2012 www.stormh2o.com erably simple to use and are acces-sible for almost any monitoring team are the Delphi method, brainstorming, and analogous studies (Liu and Liptak 1997, USEPA 1998b). Evaluation of impacts signiﬁ cance. It can be said that the most critical element of impact analysis is to determine whether the impacts will produce a signiﬁ cant effect on the monitoring project (Sadler 1996). The degree of signiﬁ cance will determine the course of action to follow. Some im-pacts will be considered signiﬁ cant and certain control or corrective measures will be required, while others may cause mini-mal or no effect on the monitoring objects and it may be decided that no further ac-tion is needed. To deﬁ ne signiﬁ cance in a WQM proj-ect, it must be taken into account that ﬁ rst, there is not a universally agree-able deﬁ nition of signiﬁ cance (Lawrence 2007), and second, professionals evaluate signiﬁ cance differently given that it de-pends on many factors, such as the context in which the impact would occur, intensity, and expert judgment, among many other things (Canter and Canty 1992, Sadler 1996). Signiﬁ cance in most WQM projects can be interpreted following the deﬁ nition of Haug et al. (1984). First, signiﬁ cance in a WQM project would ultimately be based on professional and expert judgment. Sec-ond, the signiﬁ cance of a particular impact would depend on one or several thresh-olds (contingent upon the different proj-ect variables on which the impact has an effect), the degree of importance of each of these variables in the fulﬁ llment of the project objectives, and the possibility that these thresholds are exceeded. The evaluation of impact signiﬁ cance in WQM projects is highly site-and proj-ect-speciﬁ c. The project team must de-ﬁ ne signiﬁ cance thresholds and criteria to address the degree of signiﬁ cance for each relevant impact depending on the project’s objectives. Decision-making is based on decision rules that the team must deﬁ ne to apply the criteria. Giving the nature of most WQM projects, this process is based highly on experience and professional judgment. Decision-making. The ultimate objec-tive of the application of impact analysis on a WQM project is to obtain the necessary information with regard to each relevant impact for decision-making. The decision-making process involves making decisions on the type of control, correction, or miti-gation measures, if any, that will be applied to monitor, control, avoid, reduce, or offset the potential adverse effects of the im-pacts on the monitoring project. Fischhoff (1990) afﬁ rms that a good de-cision depends “on a combination of good process and good outcomes,” and in en-vironmental situations, judgment is com-monly employed in the decision-making process. In order to support an effective decision-making process, tools to improve the quality of the judgment and appropri-ate methods of data presentation must be employed (Fischhoff 1990, Conboy et al. 2009). It must be remembered that data are not information (Wang et al. 2001). For data to become information, Green and Petre (1996) state that it must be presented in a usable format, and to facilitate effec-tive decision-making, the format must be selected to communicate the information meaningfully (Bhatia 2005). Therefore, for an effective decision-making process, it is very important that an adequate method-ology to organize and summarize the data is employed. Formats commonly used to present impact analysis data for decision-making are checklists and matrices (both

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