INDEXED SEQUENTIAL HYDROLOGIC MODELING FOR HYDROPOWER CAPACITY ESTIMATION

The indexed sequential hydrologic modeling (ISM) methodology is utiliz ed by the Western Area Power Administration as the basis for risk-base d estimation of project-dependable hydropower capacity for several fed erally owned/operated projects. ISM is a technique based on synthetic generation of a series of overlapping short-term inflow sequences obta ined directly from the historical record. The validity of ISM is asses sed through application to the complex multireservoir hydropower syste m of the Colorado River basin for providing risk estimates associated with determination of reliable hydrogeneration capacity. Performance o f ISM is compared with results from stochastically generated streamflo w input data to the Colorado River Simulation System (CRSS). Statistic al analysis and comparison of results are based on monthly power capac ity, energy generation, and downstream water deliveries. Results indic ate that outputs generated from ISM synthetically generated sequences display an acceptable correspondence with those obtained from stochast ically generated hydrologic data for the Colorado River Basin.