Effects of sampling strategies and estimation algorithms on total nitrogen load determination in a small agricultural headwater watershed

JOURNAL OF HYDROLOGY

卷:579

Article

Li, Ying¹  Yen, Haw²  Harmel, R. Daren³  Lei, Qiuliang¹  Zhou, Jiaogen⁴  Hu, Wanli⁵  Li, Wenchao¹  Lian, Huishu¹  Zhu, A-Xing^6,7  Zhai, Limei¹  Wang, Hongyuan¹  Qiu, Weiwen⁸  Luo, Jiafa⁹  Wu, Shuxia¹  Liu, Hongbin¹  Li, Xiaohong¹ 

[1] CAAS, Inst Agr Resources & Reg Planning, Minist Agr & Rural Affairs China, Key Lab Nonpoint Source Pollut Control, Beijing 10081, Peoples R China

[2] Texas A&M Univ, Texas A&M AgriLife Res, Blackland Res & Extens Ctr, Temple, TX 76502 USA

[3] ARS, Ctr Agr Resources Res, USDA, Ft Collins, CO 80526 USA

[4] Huaiyin Normal Univ, Sch Urban & Environm Sci, Huaian 223300, Jiangsu, Peoples R China

[5] Yunnan Acad Agr Sci, Inst Agr Resources & Environm, Kunming 650205, Yunnan, Peoples R China

[6] Nanjing Normal Univ, Key Lab Virtual Geog Environm, Minist Educ, Nanjing 210023, Jiangsu, Peoples R China

[7] Univ Wisconsin, Dept Geog, Madison, WI 53706 USA

[8] New Zealand Inst Plant & Food Res Ltd, Private Bag 4704, Christchurch 8140, New Zealand

[9] AgResearch, Ruakura Res Ctr, 10 Bisley Rd, Hamilton 3214, New Zealand

关键词: Total N monitoring;    Measurement uncertainty;    Load estimation;    Sampling frequency;   

DOI  :  10.1016/j.jhydrol.2019.124114

来源: Elsevier

【 摘 要 】

Monitoring data collected from rivers are used to support assessments of the quality of the river environment and help decision makes formulate appropriate management plans. Therefore, accurate and precise estimates of constituent fluxes in streams and rivers are important. However, seasonal errors have not received enough attention and the published results have rarely been verified by other methods. In this study, the error associated with sampling frequencies (3 daily, weekly, 2 weekly, 4 weekly, 6 weekly, 8 weekly) and seven load estimation algorithms were examined. Seasonal and annual total N loads were estimated and wavelet coherence was used as a reference. In order to reduce the contingency of the results, three years data were used and total N (with 17.53% particulate N, 58.70% NO3-N and 23.77% other dissolved N fractions) was chosen to reflect water quality parameters. Results indicated that 2 weekly sampling frequency and algorithm F (linear interpolation) are sufficient for evaluating the characters of annual total N load in Fengyu River Watershed with 5% RMSE (root-mean-square error). There was a large RMSE (3.97-44.66%) in summer with a high CV (coefficient variation) (35.2%) for total N concentration. These results can serve as a useful reference for decision makes who need to establish monitoring programmes in watersheds with similar characteristics.

【 授权许可】

Free