Summary: | 碩士 === 國立臺灣大學 === 農業工程學系研究所 === 86 === Recently, the development of water resource is an urgent task for the
government due to the stong water demands in Taiwan. One of the
effective methods to store surface water is to build a dam and form a
reservoir. However, there will be many difficulties in building a dam
such as lack of suitable dam sites, high cost of dam construction, related
environmental impacts. On the other hand, reservoir sedimentation
problems are serious in Taiwan because of the high sediment supply from
its watershed. Therefore, to restore and sustain the useful lift of the
reservoir is the most important issue for reservoir operation and
management.
To achieve the goal of preserving long-term reservoir capacity, the
feasibility of flushing sediments through a reservoir will be investigated in
this study. Based on the water supply and the water usage to flushing
operations, the operational rules of reservoir is adjusted and evaluated.
Genetic algorithms employed in operational simulation model is used to
optimize the reservoir operational rules.
The sediment flushing model is established to estimate outflow
sediment discharge. The sediments flushing model consists of the water
surface profile calculation and bed elevation calculation. Meanwhile, the
outflow sediment discharge calculated is used to construct the updated
line for the reservoir operators when flushing operations are performed.
reservoir elevation-storage curve.
The operational simulation model is then combined with the flushing
sediment model for simulating operational rule curve which is optimized
by the genetic algorithm. From the simulated results based on the
shortage index (SI), it is found that the best flushing sediment timing is in
May or in June every year. The operational rule obtained by the model
can be a guideline for the reservoir operators when flushing operations are
performed.
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