Holocene erosion triggered by climate change on the central Loess Plateau of China

Abstract. Understanding changes in Holocene erosion is essential for predicting soil erosion in the future. However, the quantitative response of natural erosion to Holocene climate change is limited for the Loess Plateau of China. In this study, two soil profiles were investigated in Luochuan and Yanchang sites on the central Loess Plateau of China, and four climate indicators, i.e. magnetic susceptibility, calcium carbonate content, total organic carbon content, and clay content (< 0.005 mm) were analysed to describe climate change. The fitted equations using modern pedogenic susceptibility, precipitation, and temperature were used to quantitatively reconstruct paleoprecipitation and paleotemperature in the Holocene. The current relationship between soil erosion intensity and precipitation was determined and used to estimate historical erosion. Results indicated that the climate was coldest and driest between 12000 and 8500 cal. yr BP, then became warmer and wetter during 8500 to 5500 cal. yr BP. The warmest and wettest climate was from 5500 to 3000 cal. yr BP and was getting colder and dryer over the last 3000 cal. yr BP. Holocene erosion intensity changed with fluctuation of mean annual precipitation, and these changes were similar in both sites. However, the peak erosion values were 20790 t km⁻² yr⁻¹ in 7500 cal. yr BP and 21552 t km⁻² yr⁻¹ in 3300 cal. yr BP in Luochuan and Yanchang sites, respectively. Furthermore, more rapidly increasing and more severe soil erosion was predicted in Yanchang site than Luochuan with a range between 4090 and 15025 t km⁻² yr⁻¹ during the last 1800 cal. yr BP. This study proposed a new quantitative method to research historical soil erosion triggered by climate change, which can not only derive detailed soil erosion intensity change with variation of climate, but also provide a way to compare different areas.