Understanding drought propagation and its implications for drought management

Droughts have been recognized as one of the most complex natural disasters, especially because they involve interactions between numerous climatological, hydrological and human processes. During a drought event, deficits in precipitation gradually translate into deficits in soil moisture, streamflow, and aquifer and reservoir storages, and eventually result in deficits in water supply for meeting human and environmental requirements. This translation process is known as drought propagation. The drought propagation mechanism of a region is influenced by its climate, watershed and human water use characteristics. Different drought propagation mechanisms from meteorological drought to hydrological drought and to agricultural and water supply drought can result in very different outcomes in terms of magnitude and duration of deficits in water availability during droughts. The objective of this dissertation is to understand drought propagation mechanisms and their controlling factors in different regions of the contiguous US (CONUS), and to provide a holistic framework for the assessment of drought impacts on natural and human systems. The first part of the dissertation focuses on meteorological droughts, which are defined as periods with deficient rainfall. The spatial and temporal patterns of multi-decadal variability of meteorological droughts are analyzed to quantify the non-stationarity in meteorological drought risk. Furthermore, the regional drivers of multi-decadal variability are identified for the assessment of meteorological drought risk in the near future. The second part of the dissertation focusses on hydrologic droughts, which are defined as periods with water deficits in streams and aquifers. The propagation of meteorological to hydrologic droughts is studied to understand how both climate and watershed properties contribute to different characteristics of hydrologic droughts in different regions. By taking the drought propagation mechanisms into consideration, the third part of the dissertation evaluates the impact of droughts on water supply systems in the CONUS and explores how the management of surface and groundwater resources in different regions can be improved. Finally, the understanding of drought propagation mechanisms is applied for identifying hotspots of drought impacts on natural and human systems in the CONUS and for providing insights for regional drought risk mitigation in the near future.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Civil Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2020

Author dc:creator

• Apurv, Tushar

Contributors dc:contributor

• Cai, Ximing
• Konar, Megan
• Kumar, Praveen
• Sivapalan, Murugesu

• Drought propagation
• drought risk

Statement dc:rights

• Copyright 2020 Tushar Apurv

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/108580

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/108580