Modeling wind and water erosion in northern China under climate and land use changes

ABSTRACT:

We developed a semi-empirical model of soil erosion by wind and water for sandy grassland areas in northern China (east of Erdos Plateau, Inner Mongolia). The model was partially validated against a recently compiled soil erosion map and was shown to accurately represent soil erosion. Simulations were then run for increased temperature and altered land use patterns. Increasing air temperature by 1°C increased average wind erosion by 31 t km⁻² yr¹ (79 ton mi⁻² yr¹), but decreased average water erosion by 5 t km⁻² yr¹ (12.7 ton mi⁻² yr¹). Converting grasslands to dry crop fields increased wind and water erosion, with increases being about the same order and range. Each 1 km² (0.386 mi²) of grasslands converted to dry crop fields resulted in an increase of 0.38 t km ⁻² yr⁻¹ (0.98 ton mi² yr⁻¹) in average soil erosion. No statistically significant interaction was found between temperature and land use. Converting grasslands into dry crop fields was about eight times as detrimental to soil conservation as increased temperature for the sandy grassland areas in northern China. Simulated results suggested that anthropogenic activity, especially changed land use, rather than climatic change was probably the major causal factor of desertification that occurred during the past century.