Risk analysis of impacts of climate change on changes in municipal wastewater production in wastewater reuse plans

Abstract

ABSTRACT Long-term changes in municipal wastewater production may disrupt wastewater reuse plans. However, no model/method has been developed to quantify the risks of climate change impacts on changes in wastewater production under relevant uncertainties. Accordingly, this research proposed a hybrid algorithm to analyze these risks under greenhouse gas concentration scenarios. This algorithm included a fuzzy risk assessment model based on six risk components and a framework for quantification of these components, which increased the relative confidence of decision-makers about risk values by 10%. The results showed that ‘considering’ and ‘ignoring’ the adaptive capacity to climate change under Representative Concentration Pathway scenarios in the risk analysis process lead to two completely different interpretations of risk. The risk difference based on these two approaches for Tehran was 50%, which was due to the occurrence of 11%–22% of untreated excess wastewater beyond capacity of wastewater reuse system under the temperature increase of 1.29°C.