Skip to main content
Advanced Search

Filters: Tags: Wind erosion (X)

36 results (27ms)   

Filters
Contacts (Less)
View Results as: JSON ATOM CSV
Biological soil crusts, consisting of cyanobacteria, green algae, lichens, and mosses, are important in stabilizing soils in semi-arid and arid lands. Integrity of these crusts is compromised by compressional disturbances such as foot, vehicle, or livestock traffic. Using a portable wind tunnel, we found threshold friction velocities (TFVs) of undisturbed crusts well above wind forces experienced at these sites; consequently, these soils are not vulnerable to wind erosion. However, recently disturbed soils or soils with less well-developed crusts frequently experience wind speeds that exceed the stability thresholds of the crusts. Crustal biomass is concentrated in the top 3 mm of soils. Sandblasting by wind can...
Field data are reported for the horizontal and vertical flux of wind-eroded sediment on an agricultural field in northern Germany. Measurements were made during a windstorm that hit the region on 18 May 1999. The magnitude of both fluxes was significantly affected by the presence of a surface crust covering the test field. Measuring the physical crust strength at 45 locations with a torvane, the relationships between crust strength (Ï„) and the horizontal (Fh) and vertical (Fv) sediment fluxes were investigated. Both fluxes decreased as the surface crust became stronger. The decay behaved as an exponential function for both types of flux. The horizontal sediment flux over a crusted surface can be accurately predicted...
This study determined the influence differing soil surface textures and vegetative covers have on the magnitude of wind erosion in a semi-arid environment. The study was conducted from March 2000 through late April 2000 on the Jornada Experimental Range approximately 37 km north of Las Cruces, New Mexico. Big Spring Number Eight (BSNE) samplers placed at nine locations, collected particulates in suspension and saltation at heights of 5, 10, 20, 50, and 100 cm from the following surfaces: loose sand, thick silty physical crust, flaky physical crust, weak desert pavement, and a forb/grass ground cover. BSNE samplers collected the largest amounts of sediment were collected in areas of loose sand and at sites directly...
Ecosystem disturbances that remove vegetation and disturb surface soils are major causes of excessive soil erosion and can result in accelerated transport of soils contaminated with hazardous materials. Accelerated wind erosion in disturbed lands that are contaminated is of particular concern because of potential increased inhalation exposure, yet measurements regarding these relationships are lacking. The importance of this was highlighted when, in May of 2000, the Cerro Grande fire burned over roughly 30% of Los Alamos National Laboratory (LANL), mostly in ponderosa pine (Pinus ponderosa) forest, and through areas with soils containing contaminants, particularly excess depleted and natural uranium. Additionally,...
Deposition of suspended dust near eroding source fields can have detrimental effects on vegetation, as well as on soil and water quality. This study was undertaken to quantify dust deposition within 200 m of a source field during wind erosion events. Erosion was measured with BSNE samplers on a small field of Amarillo fine sandy loam at field at Big Spring, TX. Suspension-sized dust discharge averaged 33 � 5 per cent of the total sediment discharge and ranged from 18�0 to 147�4 kg m?1 during eight selected storm events. Within 200 m of the source field boundary, dust collected in deposition samplers placed above a vegetated surface averaged 34 per cent of initial dust discharge. Predicted deposition, according to...
The recent upsurge in research attention to aeolian dust has shown that dust transport systems operate on very large spatial and temporal scales, and involve much larger quantities of sediment than was previously realized. An inevitable consequence of this is that researchers from a range of neighbouring disciplines, including ecology, are beginning to realize that this new knowledge has important implications for their study areas. In the present paper, we examine the ecological implications (real and potential) of this expanding knowledge of dust transport systems, with a particular emphasis upon the Australian dust transport system. We track these ecological effects from source to sink. At source, wind erosion–soil–vegetation...
Semiarid forests across the western USA and elsewhere are being thinned to reduce risk from fire, restore previous ecological conditions, and/or salvage trees from recently burned areas. Prescriptions and monitoring for thinning generally focus on biotic characteristics of vegetation, like tree density, rather than abiotic characteristics of soils and their loss, which are usually only considered in association with water erosion. Recent studies indicate that sediment transport by wind in forests is substantial and can exceed water transport, yet forest wind erosion responses to tree thinning and/or burning are unknown. We measured wind-driven horizontal dust flux, a metric related to wind erosion, with respect...
thumbnail
This study provides a fast and easy-to-apply method to estimate threshold friction velocity (TFV) of wind erosion in the field. Wind tunnel experiments and a variety of ground measurements including air gun, pocket penetrometer, torvane, and roughness chain were conducted in Moab, Utah and cross-validated in the Mojave Desert, California. Patterns between TFV and ground measurements were examined to identify the optimum method for estimating TFV. The results show that TFVs were best predicted using the air gun and penetrometer measurements in the Moab sites. This empirical method, however, systematically underestimated TFVs in the Mojave Desert sites. Further analysis showed that TFVs in the Mojave sites can be...
thumbnail
These data were compiled to investigate the control of drying on the aeolian transport of river-sourced sand. Objectives of our study were to to examine aeolian sediment transport during a five-day period of low steady river flow on a river sandbar and adjacent aeolian dunefield. These data represent the observed and theoretical threshold fiction velocities for aeolian sediment transport, as well as the grain size, sediment moisture content, surface roughness and other characteristics of the sandbar and sand dune surfaces. These data were collected at a sandbar and aeolian sand dune along the Colorado River approximately 19 km downstream from Glen Canyon Dam at Lees Ferry, Arizona, USA from March 15 to 20, 2021....
Categories: Data; Tags: Arizona, Climatology, Colorado River, Ecology, Geography, All tags...
thumbnail
This dataset shows high risk of water erodibility. This means the NRCS water erodibility Kw factor is < 0.20 (and slope is > 40%), or Kw factor is between 0.20 and 0.36 (and slope is > 35%) or Kw factor is > 0.36 (and slope is > 25%. These data were drawn from the 1:24,000 SSURGO soil surveys and the USGS National Elevation Dataset (NED)
thumbnail
The focus of the study, associated with these data, is a 540-km2 area at the low-elevation northern end of the 1460-km2 Milford Flat Fire in west-central Utah, and includes burned and adjacent unburned areas. Uncontrolled wildfire in arid and semiarid ecosystems has become an increasing concern in recent decades. Active rehabilitation of fire-affected areas is often quickly initiated to minimize long-term ecosystem damage. However, the complex soil-geomorphic-vegetation patterns and low and variable moisture conditions in these regions makes restoration challenging. To further inform these post-fire management decisions, we present results from 5-years of vegetation and sediment flux monitoring following the Milford...
thumbnail
These data provide the locational coordinates, soil texture characteristics, plant species occurrence and cover, and vegetation summary characteristics for the Tsezhin bii region in the south-central area of the Navajo Nation. They were collected in the fall of 2004 and their subsequent analysis reported in the paper titled 'Vegetation of semi-stable rangeland dunes of the Navajo Nation, Southwestern USA' in the journal Arid Lands Research and Management in 2016.
Aeolian processes are of particular importance in dryland ecosystems where ground cover is inherently sparse because of limited precipitation. Dryland ecosystems include grassland, shrubland, savanna, woodland, and forest, and can be viewed collectively as a continuum of woody plant cover spanning from grasslands with no woody plant cover up to forests with nearly complete woody plant cover. Along this continuum, the spacing and shape of woody plants determine the spatial density of roughness elements, which directly affects aeolian sediment transport. Despite the extensiveness of dryland ecosystems, studies of aeolian sediment transport have generally focused on agricultural fields, deserts, or highly disturbed...
The interactions between playa hydrology and playa-surface sediments are important factors that control the type and amount of dust emitted from playas as a result of wind erosion. The production of evaporite minerals during evaporative loss of near-surface ground water results in both the creation and maintenance of several centimeters or more of loose sediment on and near the surfaces of wet playas. Observations that characterize the texture, mineralogic composition and hardness of playa – surfaces at Franklin Lake, Soda Lake and West Cronese Lake playas in the Mojave Desert (California), along with imaging of dust emission using automated digital photography, indicate that these kinds of surface sediment are...
Soil erosion is an important process in dryland ecosystems, yet measurements and comparisons of wind and water erosion within and among such ecosystems are lacking. Here we compare wind erosion and transport �eld measurements with water erosion and transport from rainfall-simulation for three different semi-arid ecosystems: a shrubland near Carlsbad, New Mexico; a grassland near Denver, Colorado; and a forest near Los Alamos, New Mexico. In addition to comparing erosion loss from an area, we propose a framework for comparing horizontal mass transport of wind- and water-driven materials as a metric for local soil redistribution. Median erosion rates from wind for vertical mass flux measurements (g m−2 d−1)...
Wind erosion and aeolian transport processes are under studied compared to rainfall-induced erosion and sediment transport on burned landscapes. Post-fire wind erosion studies have predominantly focused on near-surface sediment transport and associated impacts such as on-site soil loss and site fertility. Downwind impacts, including air quality degradation and deposition of dust or contaminants, are also likely post-fire effects; however, quantitative field measurements of post-fire dust emissions are needed for assessment of these downwind risks. A wind erosion monitoring system was installed immediately following a desert sagebrush and grass wildfire in southeastern Idaho, USA to measure wind erosion from the burned...
Wind erosion researchers need field equipment and techniques for ascertaining threshold wind velocities and the amount and vertical distribution of the eroded soil particles. To detect moving soil particles and field erosion, sensors and soil samplers to measure surface creep and airborne particles have been developed. A power expression will describe the variation in amounts of suspended material to a 2-m height. The quantity of material (f) and height of material (y) within the saltation zone can be explained by the expression f = f ~ ( l - ~ / o ) $ where "fo" is surface creep, o is height below which 50% of the total mass flow occurs in the saltation process, and is the slope of the line. With this equipment...
On subwatersheds of the Walnut Gulch Experimental Watershed measurements of precipitation and runoff showed extreme variation in the rainfall-runoff relation. This variation is attributed to irregularity of amount, intensity, and dislribution of the precipitation and to unmeasured differences among the subwatersheds. To ascertain effects of soil on infiltration, rain gages and Bouyoucos moisture blocks were installed on a 4.5-acre, grass-covered drainage area of igneous soil and on a 3.0-acre drainage area of calcareous soil supporting a shrub cover. Soil in the grassland area showed greater and more abrupt responses to rainfall at the 6- and 18-inch depths. Moisture depletion at the 6-inch depth was more rapid...
Wind is a persistent force in arid and semiarid lands. Microphytic crusts have been attributed with the ability to reduce wind erosion because of soil binding qualities. The purpose of this research was to determine if microphytic crusts contribute to soil stability in an arid land setting. Threshold friction velocity is the wind speed necessary for the initiation of soil erosion and, thus, is a measure of soil surface stability. A portable wind tunnel was used to determine threshold friction velocity on soil surfaces consisting of microphytic crusts living and undisturbed (control), chemically killed microphytic crusts but otherwise undisturbed (chemically killed), and microphytic crusts mechanically removed from...
An ongoing project monitors modern dust accumulation in the arid southwestern United States to (1) determine the rate and composition of dust inputs to soils and (2) relate dust accumulation to weather patterns to help predict the effects of climate change on dust production and accumulation. The 16-year records of 35 dust-trap sites in the eastern Mojave Desert and southern Great Basin reveal how generation and accumulation of dust, including the silt-clay, carbonate, and soluble-salt fractions, is affected by the amount and seasonal distribution of rainfall and the behavior of different source types (alluvium, dry playas, and wet playas). Accumulation rates (fluxes) of the silt-clay fraction of dust, including...
map background search result map search result map A simple method to estimate threshold friction velocity of wind erosion in the field Soils with High Risk of Water Erodibility - Southern Rockies LCC - South, USA Milford Flat Fire—Data Tsézhin Bii’ Field and Summary Data 2004 - Data Threshold friction velocities for aeolian transport of river-sourced sand, with related moisture content, grain size, topographic, and wind data from Lees Ferry, Arizona Threshold friction velocities for aeolian transport of river-sourced sand, with related moisture content, grain size, topographic, and wind data from Lees Ferry, Arizona Milford Flat Fire—Data Tsézhin Bii’ Field and Summary Data 2004 - Data A simple method to estimate threshold friction velocity of wind erosion in the field Soils with High Risk of Water Erodibility - Southern Rockies LCC - South, USA