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

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

INTERNATIONAL JOURNAL OF SEDIMENT RESEARCH

IRTCES

Año: 2022

1001-6279

detailed analysis of horizontal and vertical PM fluxes during wind erosion has beenconducted, based on measurements of PM 10 , PM 2.5 and PM 1.0 concentrationsat windward and leeward positions on a measuring field. The three fractions of PM aredifferently influenced by the increasing wind and shear velocities of the wind. Themeasured concentrations of the coarser fractions of the fine dust, PM 10 and PM 2.5, increase with wind and shear velocity, whereas PM 1.0 concentrations show noclear correlation to the shear velocity. The share of PM 2.5 on PM 10 depends onthe measuring height and wind speed and varies between 4 to 12 m s -1 in 1 m heightranging from 25 to 7 % (average 10%), and in 4 m height from 39 to 23 % (average30%). Although general relationships between wind speed, PM concentration, andhorizontal and vertical fluxes could be found, the contribution of the measuring fieldwas very low, as balances of incoming and outgoing fluxes show. Consequently, themeasured PM concentrations are determined by a variety of sources, such as traffic onunpaved roads, cattle drives, tillage operations and wind erosion, and thus representall components of land use and landscape structure in the near and far surroundings ofthe measuring field. Our results may rather reflect factors from the landscape scalethan being influenced by field-related variables.The used measuring devices to monitorPM concentrations showed differences of up to 20%, which led to considerabledeviations when determining total balances. Differences up to 67% between thecalculated fluxes prove the necessity of a previous calibration of the used devices.