On an improved sub-regional water resources management representation for integration into earth system models

摘要

Human influence on the hydrologic cycle includes regulation and storage,consumptive use and overall redistribution of water resources in space andtime. Representing these processes is essential for applications of earthsystem models in hydrologic and climate predictions, as well as impactstudies at regional to global scales. Emerging large-scale researchreservoir models use generic operating rules that are flexible for couplingwith earth system models. Those generic operating rules have been successfulin reproducing the overall regulated flow at large basin scales. This studyinvestigates the uncertainties of the reservoir models from differentimplementations of the generic operating rules using the complexmulti-objective Columbia River Regulation System in northwestern UnitedStates as an example to understand their effects on not only regulated flowbut also reservoir storage and fraction of the demand that is met. Numericalexperiments are designed to test new generic operating rules that combinestorage and releases targets for multi-purpose reservoirs and to compare theuse of reservoir usage priorities and predictors (withdrawals vs.consumptive demands, as well as natural vs. regulated mean flow) forconfiguring operating rules. Overall the best performing implementation iswith combined priorities rules (flood control storage targets and irrigationrelease targets) set up with mean annual natural flow and mean monthlywithdrawals. The options of not accounting for groundwater withdrawals, oron the contrary, of assuming that all remaining demand is met throughgroundwater extractions, are discussed.