DISAGGREGATION MODELING PROCESS FOR CLIMATIC TIME-SERIES

To assess the potential effects of climatic changes on water resources , it is important to incorporate predictions of future climatic trends into hydrologic planning models. Disaggregation models can be used to produce a time series at one resolution from a parent series at a dif ferent scale. In this study, a disaggregation approach is used to gene rate a time series simulating surface air temperature and precipitatio n An annual series is generated using a 70-year record from Sacramento , California, and each year is disaggregated into 24 seasonal values. The output series from this modeling process are compared with the his torical record. It is found that the statistical and correlation chara cteristics of the historical series are well maintained. The synthetic and historical series are applied to a reservoir-sizing model, and op timal reservoir sizes are found to be statistically similar. The resul ts indicate the potential usefulness of this technique for generating synthetic temperature and precipitation to use in hydrologic planning based on future climate scenarios.