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The Tarim Basin is a major source of windblown dust in China. Land management and use can greatly impact windblown dust, thus, models such as the Wind Erosion Prediction System (WEPS) are important for identifying management practices that reduce the emission of dust. The objective of this study was to test the performance of the WEPS erosion submodel (the Single-event Wind Erosion Evaluation Program (SWEEP)) under contrasting agricultural land use types in the Tarim Basin of northwest China. Wind erosion of a sandy soil was measured and simulated in a cotton (Gossypium hirsutum L.) field and red date (Ziziphus jujuba L.) orchard during the spring of 2012 and 2013. The SWEEP did not simulate differences in soil loss for contrasting agricultural land use types, although measured soil loss was typically smaller than that considered to be of consequence (>100 g m-2) in the original design of the SWEEP. In fact, the model simulated no erosion for all six high wind events in which we observed erosion in the cotton field and red date orchard. The insensitivity of SWEEP to simulate erosion was caused by the simulated friction velocity being consistently lower than the threshold friction velocity for the loess soil at the cotton field and red date orchard. Because SWEEP is being used to assess wind erodibility of lands and simulate regional air quality in China, SWEEP must be improved for application to lands that emit large and small amounts of windblown dust. [ABSTRACT FROM AUTHOR]

Fine particulates less than 2.5 μm (PM2.5) or 10 μm (PM 10) are often emitted from river bank or other alluvial lands to the atmosphere during dry and windy seasons worldwide, which contribute to land degradation and poor air quality. Investigation of PM2.5 and PM10 emission potential could contribute to the development of mitigation strategy and better land management practices. In the lowprecipitation zone (<100 mm annual precipitation) of the Tarim Basin in westem China, wind erosion and fugitive dust emission are recognized problems on the oasis. There is limited information, however, regarding wind erosion on river overflow areas, areas of temporal flooding, in the Tarim Basin. The objectives of this study were to characterize PM2.5 and PM1O emission potential and wind erosion potential of soils along the Tarim River. The results of particle analysis revealed that most soils (28 soils) were silt loam in the overflowing area of the quc Tarim River; few (12 soils) soils were sandy loam. The soils had low clay and high silt contents. Soil particles greater than 840 μm (nonerodible soil 20( particles) were not found by sieving all soil samples. Contents of PM2.5 and PM1O ranged from 1.6 to 30.4% and 4.5 to 78.6%. These high percentages of fine soil particulates suggest that mitigation of soil wind erosion and fine-particle emission is important in protecting air quality in the region. The highest content (449%) of saltation-size particles (100- to 500-pm diameter) was found in the lower reaches of the river, followed by the middle reaches (14.6%) and then the upper reaches are (11.7%) of the river. The highest content of suspension particles (<100-μm reg diameter) was observed for soils in the middle reaches (13.1%), followed by the upper reaches (11.2%) and the lower reaches (7.1%). [ABSTRACT FROM AUTHOR]