中文摘要：

碳同位素的作文(14C， 13C ) 并且推迟的沉积的明显的年龄在年里在珍珠河里被决定 1998， 2000 和 2005。这些结果显示那个推迟的停靠港主要由年轻的碳和某旧碳组成。推迟的停靠港的明显的年龄从 540 ～ 2050 一 BP 。当这些值在 Dongjiang 河里是可变的时，明显的年龄在 Xijiang 和 Beijiang 河里是更旧的，包括旧、年轻的样品。推迟的停靠港 13C 与在珍珠河里增加 14C 珍视增加，显示它的来源是从在 1530 厘米下面的深度的土壤和基岩。因为当它进入河时，表面土壤的器官的碳快速被分解，它的碳同位素的特征在推迟的沉积是不足道的。在珍珠河排水盆，比其它有有更严重的土壤侵蚀的区域。例如，当时，侵蚀在 Xijiang 河排水盆是更严重的与在 Dongjiang 河排水盆的轻土壤侵蚀相比。

英文摘要：

The carbon isotopic composition （Δ 14 C,δ 13 C） and apparent ages of suspended sediment were determined in the Pearl River in the years 1998,2000 and 2005.These results indicate that suspended POC consists mostly of young carbon and some ＂old carbon＂.Apparent ages of suspended POC range from 540 to 2050 a BP.The apparent ages are older in the Xijiang and Beijiang Rivers,while these values are variable in the Dongjiang River,including old and young samples.The suspended POCδ 13 C values increase with increasing Δ 14 C in the Pearl River,indicating that its source is soil and bedrock from depths under 15 30 cm.Since the organic carbon of the surface soil is quickly decomposed when it enters the rivers,its carbon isotopic characteristics are insignificant in suspended sediment.In the Pearl River drainage basin,there are areas with more severe soil erosion than others.For example,erosion is much more severe in the Xijiang River drainage basin when compared to the light soil erosion in the Dongjiang River drainage basin.