Climate variability and change

Abstract

Up until relatively recently, water management and planning processes, including planning for extreme events such as droughts and floods, were largely based on the assumption of a stationary climate-that is, the assumption that the historical record (of climate and streamflow) is representative of current and future conditions. More specifically, as described by Milly et al. (2008), stationarity implies: that any variable (e.g. annual streamflow or annual flood peak) has a time-invariant (1-year-periodic) probability density function (pdf), whose properties can be estimated from the instrument record… The pdfs, in turn, are used to evaluate and manage risks to water supplies, waterworks, and floodplains….