Exploiting climate state information in urban water supply planning and operation

Traditional approaches to secure urban water supply against drought typically rely on the evaluation of long-term drought risk without taking into consideration climate information that affects short and medium drought risk. This study seeks to explore, how such climate information can improve urban water resources management. For instance, if it would known that there is a high probability that the next decade will be drier than normal, how should planning for drought security be conducted? The Interdecadal Pacific Oscillation (IPO) has been identified as being associated with decadal periods of dry and wet persistence on the east coast of Australia. The value of using the IPO index is explored through a series of Monte Carlo experiments involving the upgrading of a single reservoir system under different climate scenarios based on different IPO initial states with different levels of separation between abnormally dry and wet decadal epochs. The optimal planning schedule is identified using multi-objective optimization for each combination of climate scenario and initial condition. The results show that the use of information about climate states associated with persistence can produce demonstrably superior outcomes. A sensitivity analysis about the strength of climate state information provides further insights