Impacts of climate change downscaling method on rainwater tank yield

Abstract

The impacts of climate change on rainwater tank yield are relatively unknown, with no studies analysing the effect of climate change downscaling method (CCDM), nor important rainwater tank parameters, on rainwater tank yield. This paper addresses these shortcomings by developing a general stochastic methodology to (1) study the impact of CCDM on rainwater tank yield and (2) understand the sensitivity of yield to important rainwater tank parameters under climate change scenarios. The methodology is applied to a case study of Adelaide, South Australia, whereby three CCDMs are compared for different tank sizes, roof sizes, demands, end uses and locations. Only small differences in rainwater tank yield between CCDMs were observed; however, at extreme percentiles the difference increased. These patterns were consistent across the important rainwater tank parameters, which when compared to the CCDMs, exhibited a much greater variability in rainwater tank yield. These findings suggest the climate change studies of rainwater tanks should include sensitivity analyses of important rainwater tank parameters and that more complex methods to account for climate change are only warranted should the study be concerned with extreme events.