A Statistical Graphical Model of the California Reservoir System. Issue 11 (27th November 2017)

• Record Type: Journal Article
• Authors: Taeb, A.; Reager, J. T.; Turmon, M.; Chandrasekaran, V.
• Is Part Of: Water resources research. Volume 53:Issue 11(2017)
• Page Start: 9721
• Page End: 9739
• Publication Date: 2017-11-27
• Subjects: water resources -- sustainability -- graphical models -- latent variables -- convex optimization; Hydrology -- Periodicals; 333.91
• DOI: 10.1002/2017WR020412
• Languages: English
• ISSNs: 0043-1397

Abstract

Abstract: The recent California drought has highlighted the potential vulnerability of the state's water management infrastructure to multiyear dry intervals. Due to the high complexity of the network, dynamic storage changes in California reservoirs on a state‐wide scale have previously been difficult to model using either traditional statistical or physical approaches. Indeed, although there is a significant line of research on exploring models for single (or a small number of) reservoirs, these approaches are not amenable to a system‐wide modeling of the California reservoir network due to the spatial and hydrological heterogeneities of the system. In this work, we develop a state‐wide statistical graphical model to characterize the dependencies among a collection of 55 major California reservoirs across the state; this model is defined with respect to a graph in which the nodes index reservoirs and the edges specify the relationships or dependencies between reservoirs. We obtain and validate this model in a data‐driven manner based on reservoir volumes over the period 2003–2016. A key feature of our framework is a quantification of the effects of external phenomena that influence the entire reservoir network. We further characterize the degree to which physical factors (e.g., state‐wide Palmer Drought Severity Index (PDSI), average temperature, snow pack) and economic factors (e.g., consumer price index, number of agricultural workers) explain these external influences. As a consequence of this analysis, we obtain a system‐wide health diagnosis of the reservoir network as a function of PDSI. Key Points: We develop a statistical graphical model to characterize the statewide California reservoir system We quantify the influence of external physical and economic factors (e.g., statewide PDSI and consumer price index) on the reservoir network Further analysis gives a system‐wide health diagnosis as a function of PDSI, indicating when heavy management practices may be needed