A dual active-restrictive approach to incorporating environmental flow targets into existing reservoir operation rules
Journal
Water Resources Research
Journal Volume
46
Journal Issue
8
Date Issued
2010
Author(s)
Shiau J.-T.
Abstract
Environmental flow schemes may be implemented through active or restrictive strategies. The former may be applied via reservoir releases, and the latter can be executed by reducing water demands. We present a dual active-restrictive approach to devising the optimal reservoir operation rules that aim to secure off-stream water supplies while maximizing environmental benefits. For the active part, a multicomponent environmental flow target (including the minimum and monthly flows) is incorporated in the operation rules. For the restrictive counterpart, we use a novel demands partitioning and prioritizing (DPP) approach to reallocating the demands of various sectors. The DPP approach partitions the existing off-stream demand and newly incorporated environmental demand and reassembles the two as the first- and second-priority demands. Water is reallocated to each demand according to the ratios derived from the prioritized demands. The proposed approach is coupled with a multicriteria optimization framework to seek the optimal operation rules for the existing Feitsui Reservoir system (Taiwan) under various scenarios. The best overall performance is achieved by an optimal dual strategy whose operational parameters are all determined by optimization. The optimal environmental flow target may well be a top-priority constant base flow rather than the variable quantities. The active strategy would outperform the restrictive one. For the former, a top-priority base flow target is essential; for the latter, the off-stream demand can become vanishingly small in compensation for the eliminated base flow target, thus promoting the monthly flow target as nearly the top-priority demand. For either the active or restrictive strategy, a prioritized environmental flow demand would provide a path toward the optimal overall performance. A significantly improved overall performance over the existing operation rules is unlikely if the active and restrictive parameters are both favorable to the off-stream demand. Copyright 2010 by the American Geophysical Union.
SDGs
Other Subjects
Active parts; Baseflows; Environmental benefits; Environmental demands; Environmental flow; Monthly flow; Multicomponents; Multicriteria optimization; Operation rules; Operational parameters; Optimal operation; Priority demands; Reservoir operation; Reservoir systems; Stream water; Water demand; Aerodynamics; Groundwater flow; Hydraulics; Reservoirs (water); Rivers; Targets; Water supply; Optimization; baseflow; environmental management; multicriteria analysis; optimization; prioritization; reservoir; resource allocation; strategic approach; sustainable development; water demand; water planning; water resource; water supply; Feitsui Reservoir; Taiwan
Type
journal article