자료유형  

 학위논문

Control Number  

0017163017

International Standard Book Number  

9798384050704

Dewey Decimal Classification Number  

628

Main Entry-Personal Name  

Gupta, Rohini Singh.

Publication, Distribution, etc. (Imprint  

[S.l.] : Cornell University., 2024

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2024

Physical Description  

286 p.

General Note  

Source: Dissertations Abstracts International, Volume: 86-03, Section: B.

General Note  

Advisor: Reed, Patrick.

Dissertation Note  

Thesis (Ph.D.)--Cornell University, 2024.

Summary, Etc.  

요약Water systems in snow-dominated Mediterranean climate regions around the world are becoming increasingly vulnerable to hydroclimate extremes. California is one such region that is experiencing cycles of drought and flood that are becoming longer, more intense, frequent, and variable under a changing climate. An understanding of the impacts of climate change on California's water system is further complicated by the natural climate variability of the region, which co-evolves with climate change to shape extremes in ways that are hard to predict and plan for. The vulnerabilities ultimately experienced by the system's diverse users is dictated by how these extremes propagate through California's complex water system, which features dynamic infrastructure and an intricate system of water rights. The challenge of comprehensively characterizing risk to users throughout California's water system motivates the need to create new methods and frameworks that (1) generate scenarios of hydroclimate futures that capture a broad range of natural variability and plausible climate changes and (2) map the impacts of these scenarios through California's institutionally complex water system down to the individual user level. This dissertation presents new research that advances the development of non-traditional methods and frameworks to guide water systems planning and management in California under uncertain climate futures. The first study introduces a novel methodology that broadens our understanding of natural variability in the region's hydroclimate by reconstructing weather regimes over the past 600 years using tree-ring based moisture proxies. Results from this assessment uncover decadal modes of variability in weather regime dynamics that far exceed that of the instrumental record, and provide one of the first multi-century reconstructions of large-scale patterns of atmospheric circulation in the region. The second study pairs this reconstruction with a stochastic weather generator to create a large, 600-year ensemble of daily weather for the San Joaquin Basin that captures the space-time structure of extremes across catchments. Plausible temperature trends and patterns of precipitation intensification are superimposed on to the weather ensembles, which are then forced through hydrologic models to create streamflow ensembles that can be used to assess the compound effects from climate change on joint flooding and drought across the basin. Results show that decision-relevant characteristics of floods and drought have varied considerably over the past 600 years, highlighting the importance of moving beyond traditional climate risk assessments based solely on the modern record. The study also illustrates that a large portion of variability in individual subbasins and spatially compounding extreme events across multiple San Joaquin subbasins can be attributed to natural variability; however, anthropogenic climate changes become more influential at longer planning horizons. The third study introduces an exploratory modeling framework to comprehensively assess risk to users in the California water system under paleo and climate change-based hydroclimate variability using a highly resolved model of the state's institutionally complex water system. Weather and streamflow conditioned on a persistent, severe megadrought from the tree-ring based reconstruction is created for twelve catchments across the San Joaquin, Sacramento, and Tulare Basins and then superimposed with plausible climate changes. The impact from these streamflow ensembles is traced through the model to quantify vulnerabilities to infrastructure and users. The results reveal unprecedented low reservoir storage levels and curtailed deliveries to users under megadrought conditions that become increasingly more frequent and severe when climate change is considered. Results also highlight asymmetries in risks to infrastructure and stakeholders associated with California's two main water projects, the State Water Project and Central Valley Project. The study emphasizes that risks to stakeholders are highly dependent on the interactions between hydroclimate drivers and institutional elements that characterize the human system component of California's water system.

Subject Added Entry-Topical Term  

Environmental engineering.

Subject Added Entry-Topical Term  

Environmental science.

Subject Added Entry-Topical Term  

Systems science.

Subject Added Entry-Topical Term  

Paleoecology.

Index Term-Uncontrolled  

Hydrologic modeling

Index Term-Uncontrolled  

Multi-objective optimization

Index Term-Uncontrolled  

Paleodata

Index Term-Uncontrolled  

Stochastic weather generator

Index Term-Uncontrolled  

Water resources planning

Index Term-Uncontrolled  

Weather regimes

Added Entry-Corporate Name  

Cornell University Civil and Environmental Engineering

Host Item Entry  

Dissertations Abstracts International. 86-03B.

Electronic Location and Access  

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Control Number  

joongbu:657682