Life cycle carbon dioxide emissions for fill dams

Abstract

The construction industry including infrastructure construction, affects the environment due to the use of a considerable amount of resources and energy. The management of the environmental effect of dams for agricultural reservoirs is especially important in South Korea because of their large scale and nationwide distribution. The objective of this study is to propose an assessment method for evaluating life cycle carbon dioxide emissions associated with fill dams and to characterize carbon dioxide emissions to use in effectively addressing the environmental concerns for infrastructures. A total of four dams were selected for the research, and the material production, use of equipment and transportation were considered as the causes of carbon dioxide emissions at the dams. The effective life cycle of a fill dam was assumed to be 100 years. The results of the research indicated that the total amount of carbon dioxide emissions were different for each dam according to their characteristics, and the results showed that the dam size is the primary cause. In addition, the carbon dioxide emissions increased as the period of use increased, and a rapid increase was indicated in 40–50 years interval of the dams’ use periods because the repair activities were concentrated in those years. Materials were the biggest contributor in the amount of total carbon dioxide emissions at all four sites and the ratio of carbon dioxide emissions caused by materials was higher than any other factors in most processes. There was little difference in the proportion of carbon dioxide emissions for each process in the total carbon dioxide emissions for the four sites. Most carbon dioxide was emitted during repair activities at the two largest dams. Activities associated with the construction process was the major source of carbon dioxide emissions at the two other dams. This difference in process carbon dioxide emissions was the result of the difference in the construction scale for the embankment elevation. The assessment method that has been proposed in this study reflects the characteristics of fill dams, and the result of estimating carbon dioxide emissions indicates that we are able to reduce carbon dioxide emissions in the life cycle of fill dams by selecting the construction materials and the repair methods with a low carbon dioxide emissions.