**Application of the AHP Method in Environmental Engineering: Three Case Studies**

Tomasz Stypka, Agnieszka Flaga-Maryańczyk and Jacek Schnotale

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/63990

#### **Abstract**

[58] Garfì M, Ferrer-Martí L, Bonoli A & Tondelli S: Multi-criteria analysis for improving strategic environmental assessment of water programmes. A case study in semi-arid

region of Brazil. Journal of Environmental Management. 2001: 92: 665–675

54 Applications and Theory of Analytic Hierarchy Process - Decision Making for Strategic Decisions

The chapter presents the application of the Analytic Hierarchy Process (AHP) method in the field of environmental management. The work shows how to use the results of environmental engineering tools or models as an input for the AHP method. Three case studies are presented: selection of the best municipal solid waste disposal system, assessment of the tap and bottled water consumption on the environment, and selec‐ tion of the heat pump for the individual home. In the first case study, the AHP analysis was required to assess the environmental impact of waste disposal system. This was done by the use of Integrated Waste Management model (IWM-1), which delivered results aggregated, at the next step, into Life Cycle Analysis (LCA) categories. The obtained results were used in the AHP analysis to choose the best scheme for the waste disposal system. In the second case study, the AHP method was used to evaluate different patterns of water drinking. Obtained results help decision makers in assessing regional and individual environmental impact if the drinking pattern changes. Selected evaluation criteria were solid waste stream, energy consumption, carbon dioxide emission, and Ecoindicator 99 H/A points. The third case study presents the method of heat pump selection. The environmental performance criteria were developed using the criteria of the ecolabeling program. All three case studies are based on real data.

**Keywords:** AHP, MSWM model, sustainable development, ecolabeling, heat pumps

#### **1. Introduction**

The Analytic Hierarchy Process (AHP) method turns up to be a useful and dominant method for solving the whole spectrum of multicriteria problems [1]. It is the most popular among

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European,Asian, andAmerican researchers in all environmental areas with the exception of air quality anditspopularityisgrowing intime [1].Atpresent,itis oftenintegratedwithothertools of decision making such as Quality Function Development (QFD), meta-heuristics, SWOT analysis, mathematical programming, and Data Envelopment Analysis (DEA) [2].

The full potential of the AHP in solving the environmental problems can be unveiled when the method is combined with the environmental tools. The environmental tools are used to develop and measure many criteria of the analyzed systems performance which are used as an input for the AHP analysis. Such tools can also help in the proper designing of the criteria hierarchy. The presented case studies show such an integrated approach where environmental tools—ecolabeling programs, Life Cycle Analysis (LCA) software or Eco-indicator 99 H/A points—are used to measure the environmental impact and deliver input information for the AHP analysis. These tools can also help build the proper structure of the hierarchy of criteria.

The first case study shows how the AHP method can be combined with the LCA waste disposal model to help select the best municipal solid waste system. Two systems, one based on incineration and the other based on landfilling, are compared. Because one of the evaluation criteria is an environmental performance, the professional solid waste management tool called Integrated Waste Management model (IWM-1) was used to calculate this environmental impact. Because the IWM-1 results are too detailed for the AHP, they, in the next step, had to be integrated into Life Cycle Analysis (LCA) impact categories. For the final integration, the AHP method was applied. The Web-HIPRE software (http://hipre.aalto.fi/) was used to conduct the analysis. Finally, the presented sensitivity analysis showed the confidence of the obtained results and pointed out the most important assumptions of the whole analysis.

The second case study shows how the AHP method combined with eco-indicators can be used to help develop municipal policy toward drinking tap and bottled water. So popular bottled water is expensive for individuals and causes problems for the environment and waste disposal communities. The goal of the project is to measure this burden to help municipality develop rational policy in this area. The impacts of drinking tap water and bottled water are estimated using criteria such as waste stream reaching landfills, energy consumption, carbon dioxide emission, and Eco-indicator 99 H/A points. The developed criteria are integrated using the AHP method, which allowed developing graphs that can be used by the decision makers to estimate results and to make appropriate proposals on policy actions toward bottled water drinkers.

The third case study shows how to select the heat pump for a house. Generally, the selection is conducted by professionals with limited attention to the personal needs of the user, or it is made by the user with limited attention to technical details. The presented AHP method combined with the ecolabeling program solves this problem. It can be used by a non-profes‐ sional to help professionally select a heat pump. The critical problem of proper criteria selection was solved with the help of the "Nordic Swan" ecolabeling program. Because sometimes costs are separated from the criteria hierarchy, the option with the Cost-Benefit Analysis (CBA) of the same heat pumps is also conducted. In this case, the AHP method is used to calculate the integrated benefit of each heat pump while the cost was calculated using the Net Present Value (NPV) indicator.

All three case studies are described in more details in Refs. [3–5].

European,Asian, andAmerican researchers in all environmental areas with the exception of air quality anditspopularityisgrowingintime [1].Atpresent,itis oftenintegratedwithothertools of decision making such as Quality Function Development (QFD), meta-heuristics, SWOT

The full potential of the AHP in solving the environmental problems can be unveiled when the method is combined with the environmental tools. The environmental tools are used to develop and measure many criteria of the analyzed systems performance which are used as an input for the AHP analysis. Such tools can also help in the proper designing of the criteria hierarchy. The presented case studies show such an integrated approach where environmental tools—ecolabeling programs, Life Cycle Analysis (LCA) software or Eco-indicator 99 H/A points—are used to measure the environmental impact and deliver input information for the AHP analysis. These tools can also help build the proper structure of the hierarchy of criteria. The first case study shows how the AHP method can be combined with the LCA waste disposal model to help select the best municipal solid waste system. Two systems, one based on incineration and the other based on landfilling, are compared. Because one of the evaluation criteria is an environmental performance, the professional solid waste management tool called Integrated Waste Management model (IWM-1) was used to calculate this environmental impact. Because the IWM-1 results are too detailed for the AHP, they, in the next step, had to be integrated into Life Cycle Analysis (LCA) impact categories. For the final integration, the AHP method was applied. The Web-HIPRE software (http://hipre.aalto.fi/) was used to conduct the analysis. Finally, the presented sensitivity analysis showed the confidence of the obtained results and pointed out the most important assumptions of the whole analysis.

The second case study shows how the AHP method combined with eco-indicators can be used to help develop municipal policy toward drinking tap and bottled water. So popular bottled water is expensive for individuals and causes problems for the environment and waste disposal communities. The goal of the project is to measure this burden to help municipality develop rational policy in this area. The impacts of drinking tap water and bottled water are estimated using criteria such as waste stream reaching landfills, energy consumption, carbon dioxide emission, and Eco-indicator 99 H/A points. The developed criteria are integrated using the AHP method, which allowed developing graphs that can be used by the decision makers to estimate results and to make appropriate proposals on policy actions toward bottled water

The third case study shows how to select the heat pump for a house. Generally, the selection is conducted by professionals with limited attention to the personal needs of the user, or it is made by the user with limited attention to technical details. The presented AHP method combined with the ecolabeling program solves this problem. It can be used by a non-profes‐ sional to help professionally select a heat pump. The critical problem of proper criteria selection was solved with the help of the "Nordic Swan" ecolabeling program. Because sometimes costs are separated from the criteria hierarchy, the option with the Cost-Benefit Analysis (CBA) of the same heat pumps is also conducted. In this case, the AHP method is used to calculate the integrated benefit of each heat pump while the cost was calculated using the Net Present Value

drinkers.

(NPV) indicator.

analysis, mathematical programming, and Data Envelopment Analysis (DEA) [2].

56 Applications and Theory of Analytic Hierarchy Process - Decision Making for Strategic Decisions
