Vegetation, substrate, and eolian sediment transport at Teesto Wash, Navajo Nation, 2009-2012

Draut, Amy E.; Redsteer, Margaret Hiza; Amoroso, Lee

Abstract:

On the Navajo Nation, southwestern United States, warming temperatures and recent drought have increased eolian (windblown) sediment mobility such that large, migrating sand dunes affect grazing lands, housing, and road access. We present an assessment of seasonal variations in sand transport, mobility, and ground cover (vegetation and substrate) within a 0.2-km² study area near Teesto Wash, southern Navajo Nation, as part of a multiyear study measuring the effects of drought on landscape stability. Sand mobility in the study area decreased substantially as one year (2010) with near-normal monsoon rainfall somewhat abated a decade-long drought, temporarily doubling vegetation cover. The invasive annual plant Russian thistle (Salsola sp.), in particular, thrived after the monsoon rains of 2010. Vegetation that grew during that year with adequate rain died off rapidly during drier conditions in 2011 and 2012, and the proportion of bare, open sand area increased steadily after summer 2010. We infer that isolated seasonal increases in rainfall will not improve landscape stability in the long term because sustained increase in perennial plants, which are more effective than annual plants at stabilizing sand against wind erosion, requires multiple consecutive seasons of adequate rain. On the basis of climate projections, a warmer, drier climate and potentially enhanced sediment supply from ephemeral washes may further increase eolian sediment transport and dune activity, worsening the present challenges to people living in this region. Connections between climate, vegetation cover, and eolian sediment erodibility in this region also are highly relevant for studies in other regions worldwide with similar environmental characteristics.

Genre:

USGS Numbered Series

ProdID:

70042225

Citation Author:

Draut, Amy E.; Redsteer, Margaret Hiza; Amoroso, Lee

Citation Contributing Office:

Geology, Minerals, Energy, & Geophysics Science Center

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Citation Language:

English

Citation Larger Work Title:

Citation LatN:

37.37

Citation LatS:

35.16

Citation LonE:

-108.24

Citation LonW:

-111.87

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Citation Phsyical Description:

iv, 71 p.; col. ill.; map (col.)

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Citation Publisher:

U.S. Geological Survey

Citation Series:

Scientific Investigations Report

Citation Series Code:

SIR

Citation Series Number:

2012-5095

Citation Search Results Text:

Vegetation, substrate, and eolian sediment transport at Teesto Wash, Navajo Nation, 2009-2012; 2012; SIR; 2012-5095; Draut, Amy E.; Redsteer, Margaret Hiza; Amoroso, Lee

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2012

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citation/reference

Text:

Vegetation, substrate, and eolian sediment transport at Teesto Wash, Navajo Nation, 2009-2012; 2012; SIR; 2012-5095; Draut, Amy E.; Redsteer, Margaret Hiza; Amoroso, Lee