Preliminary results of the study on wind erosion in the Qinghai-Tibetan Plateau using Cs-137 technique

The worldwide fallout of caesium-137 (Cs-137) associated with the nuclear w eapon tests during the 1950s and 1960s has provided a valuable man-made tra cer for studies of soil erosion and sediment delivery. But relatively few r esearchers have used it to estimate wind erosion. In this note, the Cs-137 technique is introduced into the studies of wind erosion and its modern pro cesses in the Qinghai-Tibetan Plateau. Two Cs-137 reference inventories of 982.11 and 2 376.04 Bq . m(-2) were established preminarily, distributed in the south and middle-north parts of the studied area respectively. By anal yzing the patterns of Cs-137 depth profiles from sampling sites, the aeolia n processes of erosion and deposition in: nearly 40 years have been reveale d, i.e. the shrub coppice dune (S1) and semi-fixed dunefields (S3) experien ced the alternation of erosion and deposition, while the grasslands (S4, S6 and S7) and dry farmlands (S5) suffered erosion only. By using Cs-137 mode l, the average wind erosion rates for shrub coppice dune (S1), semi-fixed d une fields (S3), dry farmlands (S5) and grasslands (S4, S6 and S7) were est imated to be 84.14, 69.43, 30.68 and 21.84 t . ha(-1) . a(-1) respectively, averaging 47.59 t . ha(-1) . a(-1) for the whole plateau, which can be reg arded as of the medium erosion standard. These results derived from Cs-137 for the first time have significant implications for the further research o f wind erosion and desertification control in the Qinghai-Tibetan Plateau.