Influence of Groundwater Management on Dust Generation

Dr. Andrew Elmore, former graduate student, Dr. Kim Vest Gardner, and colleagues from the College of William and Mary and the University of California, Los Angeles, used funding from the National Science Foundation to study interactions between groundwater, soil and vegetation properties, and desert dust generation in Owens Valley, California. Wind erosion of desert soils is thought to cause irreversible change to ecosystems, and the mobilized particulate matter can seriously degrade air quality. In deserts globally, regions that produce the most dust are characterized by low elevation depressions where wind erodible material has been and continues to be deposited fluvial processes. Shallow groundwater is often pumped from these regions for agricultural and municipal use. Since water demands are rapidly increasingly in many desert regions, there is increasing need to understand how groundwater management might influence dust generation. Ideally, information could be attained that would guide groundwater management with the goal of promoting soil stability.

UMCES graduate student, Kim Vest Gardner, extracts a soil profile, one centimeter at a time, from mollisols in Owens Valley, California. Each soil layer was measured for fallout radionuclides useful for understanding soil stability over timescales from months to a few decades.

 This project uses measurements of vegetation (from field measurements and remote sensing), soil conditions and wind velocities to model wind erosion at a range of sites that experienced successively greater groundwater fluctuation over the past 20 years. We compared these model results with direct measurements of recent soil loss using radiogenic fallout isotopes and dust traps. Finally, measurements of soil resource availability (nutrients and soil moisture) are being used to understand feedback processes between groundwater decline, soil loss, and ecosystem changes that might promote continued soil instability. The project has had a broad impact on our understanding of the role water management has on dust and air quality in deserts, including an economic analysis of tradeoffs between groundwater extraction and restoration costs should groundwater decline below the rooting depth of native grasses. The work has fostered collaborations between academic institutions and environmental groups in the Owens Valley, California. The Inyo County Water Department, the Great Basin Unified Air Pollution Control District, and the Los Angeles Department of Water and Power have provided necessary data and expertise to the project and gained important information on how their vegetation and air quality management activities could be tailored to attain long-term sustainability.

Publications related to this project

Kaste, JM AJ Elmore, KR Vest, and GS Okin (2016) Groundwater controls on episodic soil erosion and dust emissions in a desert ecosystem. Geology. 44:771-774.

Gutrich, J, K Gigliello, K Vest, and AJ Elmore (2016) Economic returns of groundwater management sustaining an ecosystem service of dust suppression by alkali meadow in Owens Valley, California.  Ecological Economics. 121:1-11

Vest, KR, AJ Elmore, JM Kaste, GS Okin, Junran Li (2013) Estimating Total Horizontal Flux within shrub-invaded groundwater dependent meadows using empirical and mechanistic models. JGR-Earth Surface, 118:1132-1146

Kaste, JM, AJ Elmore, K Vest, GS Okin. (2011) Cosmogenic Be-7 in surface soils along an arid precipitation gradient in Owens Valley, CA. Geophysical Research Letters, 38, L09401, doi:10.1029/2011GL047242

Elmore, AJ, JM Kaste, GS Okin, and MS Fantle (2008) Groundwater influences on atmospheric dust generation in deserts. Journal of Arid Environments, 72:1753-1765