Condensed disaggregation procedures and conservation corrections for stochastic hydrology

Disaggregation models are perhaps the best available method for generating multiseasonal multsite streamflow sequences for use in water resource system simulations. They are the basis of two general packages: LAST and SPIGOT. Both packages use staged disaggregation procedures and condensed disaggregation models to avoid the excessive number of parameters required by the multisite monthly Valencia‐Schaake model. This paper examines the model size issue and what is gained and lost by the use of condensed models. In particular, when modeling the normal transforms of streamflow volumes, generated seasonal flows generally fail to sum to the specified annual total. A Monte Carlo study demonstrates that the discrepancy can be quite large and that alternative correction schemes perform quite differently.