Musings on a Model: CalSim II in California's Water Community

Ferriera, Inés; Tanaka, Stacy K.; Hollinshead, S. P.; Lund, Jay R.

doi:10.15447/sfews.2005v3iss1art3

Cited by 6 publications

(4 citation statements)

References 6 publications

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“…CalSim 2 has been applied in other climate‐change studies (Anderson et al, ; Brekke et al, , ; Dracup et al, ; Vicuna et al, ). While there are valid criticisms of the model (e.g., Ferreira et al, ), the performance metrics of the modeling approach used in this study (see section 3.1 and Knowles & Cronkite‐Ratcliff, ) were deemed sufficient for the present application. Key limitations and associated caveats are discussed in sections 2.7 and 4.…”

Section: Setting and Methodsmentioning

confidence: 99%

Responses of Unimpaired Flows, Storage, and Managed Flows to Scenarios of Climate Change in the San Francisco Bay‐Delta Watershed

Knowles

Cronkite-Ratcliff

Pierce

et al. 2018

Water Resources Research

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Projections of meteorology downscaled from global climate model runs were used to drive a model of unimpaired hydrology of the Sacramento/San Joaquin watershed, which in turn drove models of operational responses and managed flows. Twenty daily climate change scenarios for water years 1980–2099 were evaluated with the goal of producing inflow boundary conditions for a watershed sediment model and for a hydrodynamical model of the San Francisco Bay‐Delta estuary. The resulting time series of meteorology, snowpack, unimpaired flow, reservoir storage, and managed flow were analyzed for century‐scale trends. In the Sacramento basin, which dominates Bay‐Delta inflows, all 20 scenarios portrayed warming trends (with a mean of 4.1 °C) and most had precipitation increases (with a mean increase of 9%). Sacramento basin snowpack water equivalent declined sharply (by 89%), which was associated with a major shift toward earlier unimpaired runoff timing (33% more flow arriving prior to 1 April). Sacramento basin reservoirs showed large declines in end‐of‐September storage. Water‐year averaged outflows increased for most scenarios for both unimpaired and impaired flows, and frequency of extremely high daily unimpaired and impaired flows increased (increases of 175% and 170%, respectively). Managed Delta inflows were projected to experience large increases in the wet season and declines in the dry season. Changes in management strategy and infrastructure can mitigate some of these changes, though to what degree is uncertain.

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Section: Setting and Methodsmentioning

confidence: 99%

Responses of Unimpaired Flows, Storage, and Managed Flows to Scenarios of Climate Change in the San Francisco Bay‐Delta Watershed

Knowles

Cronkite-Ratcliff

Pierce

et al. 2018

Water Resources Research

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“…It focuses on SWP and CVP water operations, but also includes some other facilities in California's Central Valley Munévar and Chung 1999;Parker 2006). CalSim II describes the system's behavior under predefined operational priorities (Close et al 2003;Ferreira et al 2005;Parker 2006). The operating priorities in CALSIM II are intended to represent the water right, environmental, and legal priorities of the system.…”

Section: California's Sacramento Valley System and The Calvin Modelmentioning

confidence: 99%

Reservoir Operating Rule Optimization for California’s Sacramento Valley

Nelson

Hui

Lund³

et al. 2016

SFEWS

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Reservoir operating rules for water resource systems are typically developed by combining intuition, professional discussion, and simulation modeling. This paper describes a joint optimization-simulation approach to develop preliminary economically-based operating rules for major reservoirs in California's Sacramento Valley, based on optimized results from CALVIN, a hydro-economic optimization model. We infer strategic operating rules from the optimization model results, including storage allocation rules to balance storage among multiple reservoirs, and reservoir release rules to determine monthly release for individual reservoirs. Results show the potential utility of considering previous year type on water availability and various system and subsystem storage conditions, in addition to normal consideration of local reservoir storage, season, and current inflows. We create a simple simulation to further refine and test the derived operating rules. Optimization model results show particular insights for balancing the allocation of water storage among Shasta, Trinity, and Oroville reservoirs over drawdown and refill seasons, as well as some insights for release rules at major reservoirs in the Sacramento Valley. We also discuss the applicability and limitations of developing reservoir operation rules from optimization model results.

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“…We show that, by explicitly formulating the non-linear relationship between reservoir storage volume and water elevation, the use of the optimal polynomial method to fit the reservoir topography is able to extensively reduce the approximation errors compared to the traditional piecewise linearization method. The piecewise linearization method is commonly used to simplify these non-linear problems in reservoir-system planning and operation models, such as that in CALSIM (Draper et al, 2004), CALSIMii (Ferreira et al, 2005) from DWR and HEC-5 from the U.S. Army Corps of Engineers (USACE, 1998). These models implement piecewise linearization for its computation efficiency and programming simplicity.…”

Section: Introductionmentioning

confidence: 99%

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

Yang

Gao

Sellars

et al. 2015

Environmental Modelling & Software

104

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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.

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Musings on a Model: CalSim II in California's Water Community

Cited by 6 publications

References 6 publications

Responses of Unimpaired Flows, Storage, and Managed Flows to Scenarios of Climate Change in the San Francisco Bay‐Delta Watershed

Responses of Unimpaired Flows, Storage, and Managed Flows to Scenarios of Climate Change in the San Francisco Bay‐Delta Watershed

Reservoir Operating Rule Optimization for California’s Sacramento Valley

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

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