Improving the multi-objective evolutionary optimization algorithm for hydropower reservoir operations in the California Oroville–Thermalito complex

Abstract

This study demonstrates the application of an improved Evolutionary optimization Algorithm (EA), titled Multi-Objective Complex Evolution Global Optimization Method with Principal Component Analysis and Crowding Distance Operator (MOSPD), for the hydropower reservoir operation of the OrovilleeThermalito Complex (OTC) e a crucial head-water resource for the California State Water Project (SWP). In the OTC's water-hydropower joint management study, the nonlinearity of hydropower generation and the reservoir's water elevationestorage relationship are explicitly formulated by polynomial function in order to closely match realistic situations and reduce linearization approximation errors. Comparison among different curve-fitting methods is conducted to understand the impact of the simplification of reservoir topography. In the optimization algorithm development, techniques of crowding distance and principal component analysis are implemented to improve the diversity and convergence of the optimal solutions towards and along the Pareto optimal set in the objective space. A comparative evaluation among the new algorithm MOSPD, the original Multi-Objective Complex Evolution Global Optimization Method (MOCOM), the Multi-Objective Differential Evolution method (MODE), the Multi-Objective Genetic Algorithm (MOGA), the Multi-Objective Simulated Annealing approach (MOSA), and the Multi-Objective Particle Swarm Optimization scheme (MOPSO) is conducted using the benchmark functions. The results show that best the MOSPD algorithm demonstrated the best and most consistent performance when compared with other algorithms on the test problems. The newly developed algorithm (MOSPD) is further applied to the OTC reservoir releasing problem during the snow melting season in 1998 (wet year), 2000 (normal year) and 2001 (dry year), in which the more spreading and converged non-dominated solutions of MOSPD provide decision makers with better operational alternatives for effectively and efficiently managing the OTC reservoirs in response to the different climates, especially drought, which has become more and more severe and frequent in California.

Evaluating the streamflow simulation capability of PERSIANN-CDR daily rainfall products in two river basins on the Tibetan Plateau

“…Many studies have been carried out to evaluate the suitability of a number of satellite-based precipitation estimate products in forcing hydrologic models and simulating streamflow for various regions around the world (e.g., Yilmaz et al, 2005;Artan et al, 2007;Su et al, 2011;Bitew et al, 2012;Yong et al, 2012, Yang et al, 2015. However, there are few evaluation studies focusing on hydrological modeling driven by satellite rainfall products on the Tibetan Plateau.…”

An Integrated Method for Interval Multi-Objective Planning of a Water Resource System in the Eastern Part of Handan

“…It can be seen that the total amount of domestic water demand is [129. 25 In detail, Figure 2 shows the amount of water allocated to municipality in each region from different water resources. It can be seen that the total amount of domestic water demand is [129.…”

“…It can be seen that the total amount of domestic water demand is [129. 25,146.25] × 10 6 m 3 , while the amount of water which is allocated to municipality is [129.25, 140.25] × 10 6 m 3 . So the water shortage is 6 × 10 6 m 3 with the average deficiency rate being 4.1% under the upper water demand, and the top two water shortage counties are Guangping County and Guantao County, whose deficit rate are 18% and 14.6% respectively.…”

Thematic issue on Evolutionary Algorithms in Water Resources

“…In this paper, a novel iterative optimisation approach is introduced, as part of which problem formulation is updated based on the results of prior rounds of optimisation. Yang et al (2015) tackle the issue of problem formulation for the real-world case study of optimising the hydropower reservoir operation of the Oroville-Thermalito Complex in California, USA. Particular attention is given to the impact of the simplification of the reservoir's highly non-linear storage-elevation relationship.…”