Tectonic, climatic, and land-use controls on groundwater recharge in an arid alluvial basin, Amargosa Desert

By: , and 
Edited by: James F. HoganFred M. Phillips, and Bridget R. Scanlon



Unsaturated-zone profiles in alluvial sediments of the Amargosa Desert reveal distinct patterns of groundwater recharge corresponding to tectono-geomorphic setting and land-use history. Profiles of water potential, water content, and solute concentrations beneath irrigated fields, undisturbed native vegetation, and the normally dry channel of the Amargosa River reflect strongly contrasting recharge regimes. Profiles beneath irrigated fields and channel sites indicate quasi-steady percolation at depths sufficient to be isolated from seasonal variations in meteorologic forcing. Displaced chloride and nitrate peaks beneath a recently converted agricultural field and a weakly incised channel site capture newly initiated deep percolation moving previously accumulated salts from the upper profile to greater depths. Channel migration caused by an extreme flood initiated deep percolation at the latter site. Downward-advected nitrate peaks beneath an irrigated field mark resumption of cultivation following eight years of dormancy. Where available, travel time estimates of recharging fluxes support chemical mass balance estimates. Recharging fluxes range from ~6 to 22% of applied water for irrigated fields and from ~12 to 15% of infiltration for channel sites. Profiles of environmental tracers beneath undisturbed native vegetation in interfluvial areas are consistent with negligible recharge and sustained profile drying throughout the Holocene. Four to five times more chloride is accumulated on older, uplifted alluvium than on younger, non-uplifted alluvium, showing that tectonic controls on recharge become important when timescales extend to many millennia. Groundwater recharge in desert basins is limited to features that occupy a small fraction of the land surface and are not necessarily stationary.

Study Area

Publication type Book chapter
Publication Subtype Book Chapter
Title Tectonic, climatic, and land-use controls on groundwater recharge in an arid alluvial basin, Amargosa Desert
Series number 9
Year Published 2004
Language English
Publisher Americal Geophysical Union
Contributing office(s) Nevada Water Science Center
Description 20 p.
Larger Work Type Book
Larger Work Subtype Monograph
Larger Work Title Groundwater recharge in a desert environment: The southwestern United States
First page 29
Last page 48
Country United States
State Nevada
County Nye County
Other Geospatial Amargosa Desert
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