Post on 09-Jan-2017
Dust TransportIn The Southwest
New Mexico State University
Elizabeth Smith New Mexico State University College of Agriculture, Consumer, and Environmental Science
Corporative Extension Services- Plant Science Las Cruces, NM
http://www.weru.ksu.edu/new_weru/multimedia/2004storms/2004storms.html
Texas Tech PresentationApril 13, 2016
Definition:
• Soil erosion due to wind is initiated by turbulent air movement across an open surface, causing stable soil particles to dislodge and to be suspended within the moving air (Wild, 1993)
New Mexico State University
New Mexico State University
Regional Description• Chihuahuan Desert ecosystem
is the most biologically diverse desert in the world, The region’s natural ecosystem has been heavily degraded over time, mainly due to grazing in the past, river channelization for agricultural activities, and urban sprawl. Many native plant species have been replaced with invasive species such as Creosote
• Southwest is considered an Arid Environment
• Nearly 50% is precipitation falls during summer monsoon(Nicholson, 2011)
• Drought conditions since 2001.
• Source pages: • http://www.wrcc.dri.edu/ New Mexico• http://www.srcc.lsu.edu/ Texas
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Regional Climate
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Wind Science
• The United States is located within the westerlies wind zone, where the wind goes from west to east normally, though local wind patterns may vary.
• In the Las Cruces and El Paso, the primary wind direction is west-southwest.
• This wind is the primary cause of erosion.
• The erodibility of a soil is dependent on the diameter, density, and shape of the particles.
New Mexico State University
How Wind Erosion and Dust Storms Start Part 1
• Creep: diameter above 0.5mm– Rolls over soil surface
• Saltation: diameter 0.05-0.5mm– Primary cause of wind
erosion• Suspension: smaller than
0.05mm– Form dust storms and
Haboobs
New Mexico State University
Videos
• Saltation Transport: • https://www.youtube.com/watch?v=xc4bbbwUnNE
• Local Videos- Lordsburg: • https
://www.youtube.com/watch?v=SwFyprF6a_g&nohtml5=False
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Haboob
New Mexico State Universityhttp://www.propertyinsurancecoveragelaw.com/uploads/image/Haboob.jpg
• http://www.mesonet.ttu.edu/cases/WallofDirtII_031814/VIS_12_031814.gif
Sources of Wind Blown Dust
• Open land/ desert areas• Public land used for recreation• Private land for future development• Residential Development projects• Recreational areas with soil arenas or
parking lots
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• The carrying capacity of wind for soil particles increases with wind speed and decreased with particle and aggregate size
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= quantity of soil removed= wind speed= particle diameter
2 m above surface
How Wind Erosion and Dust Storms Start Part 2
Why is Wind Blown Dust an Issue?
• What is PM10?– particulate matter with an aerodynamic diameter
less than or equal to a nominal ten micrometers • Why is it a problem?
– Health– Personal Property– Environmental Problems
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Counties Designated Non-Attainment for PM-10
http://www.asl-associates.com/Images/currentpm10.jpg
Health Issues Related to Wind Blown Dust
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Homeowner Issues
• From Homeowners in Southwest area:
– Scours Roofing– Destroys Landscape– Sand Dune occurrence at fence line– Reduction of indoor air quality
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Environmental Issues
• Loss of soil to support growth of plants (crops, grasses, forests)
• Deposition of sediment loads into natural and man-made waterways
• Water Pollution– 1t contains 0.2% N/ 0.05% P = 2kg N/0.5 kg P
• Air Pollution– Reduce solar radiation at the surface– Change chemical processes in the atmosphere
New Mexico State University
How Wind Erosion and Dust Storms Start Part 1
• Creep: diameter above 0.5mm– Rolls over soil surface
• Saltation: diameter 0.05-0.5mm– Primary cause of wind
erosion• Suspension: smaller than
0.05mm– Form dust storms and
Haboobs
New Mexico State University
Equipment Passive• BSNE• Passive Marble Traps
Active• High Volume, Continuous
air-flow sampler• Dust-Track
– Sucks in samples• Gravimetric Dust Sampler
– Provides time-weighted-average respirable dust concentration
New Mexico State Universityhttp://esp.cr.usgs.gov/projects/sw/swdust/marble_traps.html, http://esp.cr.usgs.gov/projects/sw/swdust/tsp_sampler.html
What is a BSNE?• Big Spring Number Eight
• As a Sample Collector: – Stationary heights:
• 50 cm– Rotating Control heights:
• 100 cm• 50 cm • 10 cm
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Sampling
• Sampling occurs in an area when gusts reached 25 mph with the National Weather Service or local weather station
OR • No high wind events have been registered for
a 1 month period
Lab Work! • Opening the BSNE
– Collection equipment consisted of (A) screwdriver (B) Deionized Water (DI water) (C) DI water distributer (D) funnel (E) individual sampling containers (Numbered), one container per BSNE (F) toothbrush.
• Preparing the Sample container– sturdy plastic 16 ounce bottles, were washed with DI water and dried
before using in the field.• Lab Process- Field Trip! (but first how it works)
New Mexico State University
sample weight = beaker with sample - beaker
New Mexico State University
Bake @ 105 °Centigrade24-48 hours later