Sensitivity Analysis of California Water Supply
Sensitivity Analysis of California Water Supply

Author: Max Fefer

Publisher:

Published: 2017

Total Pages:

ISBN-13: 9780355451450

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Long-term changes in climate and population will have significant impacts on California’s freshwater management. Hydro-economic models can address climate change concerns by identifying system vulnerabilities and exploring adaptation strategies for statewide water operations. This thesis combines the new Python implementation of the CALVIN model, a hydro-economic model describing California water resources, with an ensemble of climate scenarios to identify adaptation strategies for managing water in a range of possible climates. A sensitivity analysis is performed by altering the magnitude and the timing of statewide inflows, defined as water availability and winter index respectively, to emulate changes in precipitation and temperature predicted by climate models. Model results show quadratic increases in shortage cost and marginal value of environmental flows, conveyance expansion, and reservoir expansion as water availability decreases. Reservoirs adapt to warmer climates by increasing average storage levels in winter and routing excess runoff to reservoirs downstream with available capacity. Both small and large changes to reservoir operations were observed compared to historical hydrology, showing that no single operating strategy achieves optimality for all reservoirs. Increasing the fraction of winter flow incurs small increases in total shortage cost, showing the state’s ability to manage a changing hydrologic regime with adaptive reservoir operations.

Valuing Water Supply Reliability with Sensitivity Analysis
Valuing Water Supply Reliability with Sensitivity Analysis

Author: Steven Buck

Publisher:

Published: 2017

Total Pages: 19

ISBN-13:

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The purpose of this paper is to calculate the expected reliability benefits of alternative water supplies that are less vulnerable to disruption than the current composition of supplies, especially those regions which rely on imported surface water. Expected reliability benefits are measured using estimates of welfare losses under various levels of supply disruption, the probability of each level disruption, and on consumption forecasts over the life of proposed alternative supplies. To consider uncertainty in reliability benefits, we run sensitivity analyses to value reliability under different discount rates, the elasticities of demand, water supply disruption levels, and corresponding probability distributions of disruption.

Energy Use in California Wholesale Water Operations
Energy Use in California Wholesale Water Operations

Author: Matthew Earl Bates

Publisher:

Published: 2010

Total Pages:

ISBN-13: 9781124508320

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This thesis explores the effects of future water and social conditions on energy consumption in the major pumping and generation facilities of California's interconnected water-delivery system, with particular emphasis on the federally owned Central Valley Project, California-owned State Water Project, and the large locally owned systems in Southern California. Anticipated population growth, technological advancement, climatic changes, urban water conservation, and restrictions of through-Delta pumping will together affect the energy used for water operations and alter statewide water deliveries in complex ways that are often opposing and difficult to predict. Flow modeling with detailed statewide water models is necessary, and the CALVIN economic-engineering optimization model of California's interconnected water-delivery system is used to model eight future water-supply scenarios. Model results detail potential water-delivery patterns for the year 2050, but do not explicitly show the energy impacts of the modeled water operations. Energy analysis of flow results is accomplished with the UC Davis General Energy Post-Processor, a new tool for California water models that generalizes previous efforts at energy modeling and extends embedded-energy analysis to additional models and scenarios. Energy-intensity data come from existing energy post-processors for CalSim II and a recent embedded-energy-in-water study prepared by GEI Consultants and Navigant Consulting for the California Public Utilities Commission. Differences in energy consumption are assessed between modeled scenarios, and comparisons are made between data sources, with implications for future water and energy planning strategies and future modeling efforts. Results suggest that the effects of climate warming on water-delivery energy use could be relatively minimal, that the effects of a 50% reduction in Delta exports can be largely offset by 30% urban water conservation, and that a 30% conservation in urban water use can produce energy savings of over 40%, from the base case. Results also show that refining estimates of future Delta export and urban water conservation levels is necessary to increase confidence in energy-related planning and investment. Sensitivity analyses suggest that the compared energy-intensity data are highly interchangeable, and using data combined from multiple sources is preferable to include more facilities without skewing results.