| A typical undulating farmland in black soil region of Northeast China was taken as a case study to analyze the properties of soil loss caused by erosional precipitation events based on measurement of sediment and its nutrients and particle size in different geomorphic positions and the outlet of the watershed.The results showed that soil loss only happened in high rainfall intensities.This study takes the runoff event on August 1st, 2006 for example.The sediment concentration in runoff is in range of 1.0～2.5 g/L. Nutrient enrichment occurred in sediment and the enrichment ratio of carbon and nitrogen is 2.10 and 3.31, respectively.The soluble carbon and nitrogen in runoff is 2.47～3.93 mg/L and 1.61～3.28 mg/L.The loss of soluble nutrients is also an important way of nutrient loss under water erosion.The aggregate size distribution of the eroded sediment was drastically different from that of the original soil.Aggregates smaller than 0.053 mm, especially the size between 0.002 mm and 0.02 mm, is the main form of the sediment. |