Horizontal and vertical fluxes of particulate matter during wind Q8 erosion on arable land in the province La Pampa, Argentina

SIEGMUND NICOLE; FUNK ROGER; SOMMER MICHAEL; AVECILLA FERNANDO; PANEBIANCO ESTEBAN; ITURRI ANTONELA; BUSCHIAZZO DANIEL

INTERNATIONAL JOURNAL OF SEDIMENT RESEARCH

IRTCES

Año: 2022

1001-6279

A detailed analysis of horizontal and vertical Particulate Matter (PM) fluxes during wind erosion has beendone, based on measurements of PM smaller than 10, 2.5, and 1.0 mm, at windward and leeward positionson a measuring field. The three fractions of PM measurement are differently influenced by theincreasing wind and shear velocities of the wind. The measured concentrations of the coarser fractions ofthe fine dust, PM10, and PM2.5, increase with wind and shear velocity, whereas the PM1.0 concentrationsshow no clear correlation to the shear velocity. The share of PM2.5 on PM10 depends on the measurementheight and wind speed and varies between 4 and 12 m/sat the 1 m height ranging from 25% to 7%(average 10%), and at the 4 m height from 39% to 23% (average 30%). Although general relationshipsbetween wind speed, PM concentration, and horizontal and vertical fluxes could be found, the contributionof the measuring field was very low, as balances of incoming and outgoing fluxes show. Consequently,the measured PM concentrations are determined from a variety of sources, such as traffic onunpaved roads, cattle drives, tillage operations, and wind erosion, and thus, represent all components ofland use and landscape structure in the near and far surroundings of the measuring field. The currentresultsmay reflect factors from the landscape scale rather than the influence of field-related variables.The measuring devices used to monitor PM concentrations showed differences of up to 20%, which led toconsiderable deviations when determining total balances. Differences up to 67% between the calculatedfluxes prove the necessity of a previous calibration of the devices used.