| dc.description.abstract | The purpose of this paper is to overcome computationally intractableness due to the curse of dimensionality for multiple reservoir operation problems in real world. GA-based automation model, which embeds Genetic Algorithm (GA) in simulation model, is chosen to discuss different coding and weight of fitness function by sensitivity analyses. Finally, 2500 years streamflow data, which is calculated by multisite streamflow generation model, is taken into GA-based automation model to get 50 sets of reservoir rule curves. All of the rule curves are stacked up to get the banded range. According to the banded range, the importance of rule curves in some time period is judged.
The study attains the following findings and conclusion:
1. When reservoir rule curves use 6 turning points, which reduces design variables from 10 to 7, the resulting optimal rule curves performs very close to those from other different coding. The difference of average shortage and the difference of the hydropower resulting from reducing design variables from 10 to 7 are only 0.63% and 0.27%, respectively. It is demonstrated that the simplified coding can reflect the feature of reservoir.
2. The objective function (i.e., Fitness = W1‧1/SI + W2‧Power + W3‧(1-R), where W1=1000,W2=1,W3=1000, SI=shortage index, Power=hydropower, R=percentage of maximum shortage ratio), derives a proper rule curves which can not only reduce the shortage amount and the duration for downstream demand but also enhance hydropower efficiency.
3. Under uncertain of future streamflow, the medium rule curves, which is obtained from rule curves resulting from 50 sets of generate streamflow data, attain better benefits in the duration of the analytic years.
4. It is found that comparing the present rule curves with medium rule curves, the present rule curves and the medium rule curves of Shihmen reservoir are close, but that of Feitsui reservoir are not. The reason is that these two reservoirs were planned for single-operation system in the initial stage. Therefore, in practice the side demand of Shihmen is relatively large that prohibits Shihmen reservoir to play an important role in the joint operation. The joint demand is almost solely supplied with Feitsui reservoir. | en_US |