Land degradation potential by soil erosion under different land uses in the dry area of Tarim Basin

摘要

Tarim Basin generates large quantities of dust that is carried by winds over large areas of Asia and across the Pacific to North America.The northwestern dry area of Tarim Bain is located in the transmission route of dust.The objective of this study was to characterize the potential wind erosion and fine particle emission in the region as affected by five different land uses.Soil from the upper 5 cm layer of the profile was collected from five major land uses in the Basin.Analysis indicated that different land uses had heterogeneous soil texture.Except for Dry channel,all soils were rich in sand,ranging from 60.1-94.5％.The clay content ranged from zero to 13.28％.There was no significant difference in soil texture between Jujube orchard and cotton,indicating that the crops had no significant effect on soil texture.For D95,the Desert riparian had highest value,the transition zone followed,the cotton and the orchard also had high values,indicating that the soil particle was coarser.The Dry channel had lowest value,was significant finer than others.The particles greater than 0.84mm were not found in any soils,thus there was no non-erodible soil in the study area.The saltation material from five treatments had high percentage except for Dry channel.The five treatments had high suspension content,especially the Dry channel(97.93％),which had highest content of PM 10 and PM 2.5,followed by the Desert riparian.The dry channel and desert riparian had high suspension,PM10 and PM 2.5,the two types of land use must have great concern for dust generation.