Using 137Cs and 210Pbex to investigate the soil erosion and accumulation moduli on the southern margin of the Hunshandake Sandy Land in Inner Mongolia

Wind-driven soil erosion results in land degradation, desertification, atmospheric dust, and sandstorms. The Hunshandake Sandy Land, an important part of the Two Barriers and Three Belts project, plays important roles in preventing desert and sandy land expansion and in maintaining local sustainability. Hence, assessing soil erosion and soil accumulation moduli and analyzing the dynamic changes are valuable. In this paper, Zhenglan Banner, located on the southern margin of the Hunshandake Sandy Land, was selected as the study area. The soil erosion and accumulation moduli were estimated using the 137 Cs and 210 Pb ex composite tracing technique, and the dynamics of soil erosion and soil accumulation were analyzed during two periods. The results are as follows: (1) the regional 137 Cs reference inventory was 2123.5±163.94 Bq/m 2 , and the regional 210 Pb ex reference inventory was 8112±1787.62 Bq/m 2 . (2) Based on the 137 Cs isotope tracing analysis, the erosion moduli ranged from –483.99 to 740.31 t·km −2 ·a −1 . Based on the 210 Pb ex isotope tracing analysis, the erosion moduli ranged from –441.53 to 797.98 t·km −2 ·a −1 . (3) Compared with the earliest 50 years, the subsequent 50 years exhibited lower soil erosion moduli and accumulation moduli. Therefore, the activities of local sand dunes weakened, and the quality of the local ecological environment improved. The multi-isotope composite tracing technique combining the tracers 137 Cs and 210 Pb ex has potential for similar soil erosion studies in arid or semiarid regions around the world.