抚仙湖典型小流域烤烟坡地产流产沙及氮磷流失特征

Characteristics of runoff and sediment and N、P loss in Nicotiana tabacum land slope in typical small watershed of Fuxian Lake

选择抚仙湖典型入湖小流域中具有代表性的烤烟坡地,采用标准径流小区法进行观测,通过2007年6—9月10场降雨产流过程的地表径流及侵蚀泥沙中的氮磷流失情况的连续监测,研究烤烟坡地产流产沙及氮磷流失特征,结果表明:1)产流量与最大10 min降雨强度相关性较强(R2=0.878 9),产沙量与最大30 min降雨强度相关性较强(R2=0.944 5);2)TN、氨氮输出浓度随施肥时间延长而逐渐降低;3)TP输出量与最大10 min降雨强度具有明显的线性相关关系(R2=0.897 1);4)TN输出量与产流量之间有显著的正相关关系,TP输出量与产流量及产沙量之间相关关系都极显著,TN与TP输出量之间有正相关关系,Pearson相关系数为0.542(sig.=0.106)。

Based on the continuous observation of the nitrogen and phosphorus loss in surface runoff and sediment in under rainfall events from June to September in 2007 with a standard plot method on a Nicotiana tabacum land slope in the typical small watershed of Fuxian Lake, this article studied the characteristics the loss of nitrogen and phosphorus with runoff and sediment, the results showed that： 1 ） The runoff amount has strong correlation with the maximum rainfall intensity of 10 minutes （R^2 = 0.8789）, and sediment yield has strong correlation with the maximum rainfall intensity of 30 minutes （R^2= 0.9445） ; 2） The loss amount concentration of TN,NH4^＋ -N gradually reduced with fertilizing time ; 3） TP loss has a significant correlation with the maximum rainfall intensity of 10 minutes （R^2=0.8971） ; 4） TN loss has a significant positive correlation with runoff amount, and TP loss has a very significant correlation with runoff amount and sediment yield, TN loss has a positive correlation with TP loss, the pearson coefficient is 0.542（sig. = 0.106）.