The Water-Energy-Environment Nexus and Climate Change: A Framework for Multi-Basin Planning
Abstract
Water-energy-environment systems that are regionally distributed are likely to be impacted by climate and socio-economic change in different ways due to regional heterogeneity in system characteristics, requiring multi-scale, multi-basin approaches to understand the broader effects of existing and proposed water, energy and environmental policies, and to identify promising new policies. This is exemplified in California's Sierra Nevada, where restoring freshwater ecosystems in the downstream, agriculturally intensive Central Valley is a priority, energy demands are continually changing, and studies have shown significant regional heterogeneity in climate change impacts. We developed a conceptual and computational framework for assessing the intra- and trans-basin trade-offs between energy, environmental and agricultural water needs considering climate and energy change. The framework combines a traditional modeling approach, applied to multiple, parallel basins. The basin-specific models are systematically perturbed in two ways: scenario analysis mode and optimization mode. In the scenario analysis mode, per-basin, policy-based management objectives are systematically perturbed to identify trade-offs between imposed policies. In the optimization mode, parallel basins are managed with unknown decision variables, with a multi-objective evolutionary algorithm (MOEA) used to identify the pareto-optimal trade-offs between management objectives both within and across basins. This framework tracks traditional modeling approaches, yet is novel in its application to multiple, parallel basins. We implemented the framework computationally for four parallel basins in the southern Sierra Nevada with a decision support system platform (OpenAgua) combined with a Python-based optimization software package designed for computational efficiency (Pywr). The framework provides a graphical modeling interface, integration of multiple subsystem models, multi-model management, as well as tools for ex post scenario analysis and MOEA visualization. We demonstrate the utility of this approach and promising extensions for full water-energy-food nexus integration.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMGC32A..02R
- Keywords:
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- 0402 Agricultural systems;
- BIOGEOSCIENCES;
- 1630 Impacts of global change;
- GLOBAL CHANGE;
- 1878 Water/energy interactions;
- HYDROLOGY;
- 6344 System operation and management;
- POLICY SCIENCES & PUBLIC ISSUES