Wang Hong, Xu Ya-Ling, Zhang Qi, Lin Chao-Wen, Zhai Li-Mei, Liu Hai-Tao, Pu Bo
Soil and Fertilizer Institute, Sichuan Academy of Agricultural Sciences, Chengdu 610066, China.
Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Huan Jing Ke Xue. 2020 Oct 8;41(10):4547-4554. doi: 10.13227/j.hjkx.202003213.
The emission of nitrogen and phosphorus via non-point source pollution from a small watershed has become the main pollution source of river waters, while climatic conditions and human activities directly affect the changes in rainfall-runoff and types of land use that are closely related to nitrogen and phosphorus pollution. In this study, we explore the runoff loss, nitrogen and phosphors concentration, and nitrogen and phosphorus emission in Huajiaogou small watershed on the upper reaches of Yangtze River. The rainfall, runoff, and temporal changes of nitrogen and phosphorus were analyzed using the continuous position monitoring data. The results showed that:① the runoff volumes were 10.05×10 m and 3.34×10 m from July 1 to September 30, accounting for 76.58% and 56.51% in 2012 and 2013, respectively, and they were positively correlated to rainfall. The peak concentrations of ammonia nitrogen (NH-N) from April 1 to June 30 were 11.51 mg ·L and 4.44 mg ·Lin 2012 and 2013, respectively. ② The NH-N emission risk period was from July 1 to September 30, accounting for 78.45% and 62.24% in 2012 and 2013, respectively. The peak concentration and emission risk period of total nitrogen (TN) and nitrate nitrogen (NO-N) were from July 1 to September 30, and NO-N was the main form of the total nitrogen emission. The peak concentration of NO-N was 6.06 mg ·L and 11.43 mg ·Lin 2012 and 2013, respectively, and the loss in NO-N from July 1 to September 30 accounted for 88.74% and 65.55% in 2012 and 2013, respectively. ③The emission risk period of total phosphorus (TP), dissolved total phosphorus (DTP), and particulate phosphorus (PP) was also from July 1 to September 30, and the particulate phosphorus was the main form of the total phosphorus emission. The particulate phosphorus emission from July 1 to September 30 accounted for 36% and 68% in 2012 and 2013, respectively, and the ration of particle phosphorus to total phosphorus was easily affected by rainfall.
小流域非点源污染产生的氮磷排放已成为河流水体的主要污染源，而气候条件和人类活动直接影响与氮磷污染密切相关的降雨径流变化和土地利用类型。本研究对长江上游花胶沟小流域的径流损失、氮磷浓度及氮磷排放进行了探究。利用连续定位监测数据，分析了降雨、径流以及氮磷的时间变化情况。结果表明：①7月1日至9月30日的径流量分别为10.05×10立方米和3.34×10立方米，分别占2012年和2013年的76.58%和56.51%，且与降雨量呈正相关。2012年和2013年4月1日至6月30日氨氮（NH-N）的峰值浓度分别为11.51毫克·升和4.44毫克·升。②氨氮排放风险期为7月1日至9月30日，分别占2012年和2013年的78.45%和62.24%。总氮（TN）和硝态氮（NO-N）的峰值浓度及排放风险期均为7月1日至9月30日，硝态氮是总氮排放的主要形式。2012年和2013年硝态氮的峰值浓度分别为6.06毫克·升和11.43毫克·升，7月1日至9月30日硝态氮的流失量分别占2012年和2013年的88.74%和65.55%。③总磷（TP）、溶解性总磷（DTP）和颗粒态磷（PP）的排放风险期也为7月1日至9月30日，颗粒态磷是总磷排放的主要形式。7月1日至9月30日颗粒态磷的排放量分别占2012年和2013年的36%和68%，颗粒态磷与总磷的比例易受降雨影响。
