Analysis of sampling interval for monitoring of agricultural non-point sources based on runoff events
WANG Chao1,2, WANG Jian3, WEN Li-qun4, QIN He5, LIU Gen1,2, JIA Hai-yan1,2, YIN Wei1,2
1. Changjiang Water Resources Protection Institute, Wuhan 430051, China; 2. Key Laboratory of Ecological Regulation of Non-point Source Pollution in Lake and Reservoir Water Sources, Wuhan 430051, China; 3. College of Resources&Environment of Huazhong Agricultural University, Wuhan 430070, China; 4. National Engineering Research Center of Advanced Technology and Equipment for Water Environment Pollution Monitoring, Changsha 410205, China; 5. Water Sources Company of South-to-North Water Diversion, Danjiangkou 442700, China
Abstract：The Wulongchi small watershed in Danjiangkou Reservoir area was selected as the object, and the real value of runoff process was taken from the High-frequency monitoring data of typical rainfall runoff events. The error of pollution load flux estimation was analyzed by simulating sampling at different time intervals and water intervals, and the effective sampling interval was determined. The results showed that the rainfall runoff event in Wulongchi Basin had obvious peak characteristics (initial discharge 55m3/h, peak discharge 977.3m3/h), the total phosphorus concentration was highly synchronized with the runoff (initial concentration 0.05mg/L, peak concentration 0.25mg/L), and the total nitrogen did not decrease significantly after reaching the peak with the runoff (initial concentration 2mg/L, peak concentration 8mg/L). In the simulated sampling with interval 5, 10, 15, 20, 30, 60, 120, 240, 480, 720min, the number of sampling points reduced from 1957 to 14. In the simulated sampling with interval 16, 32, 64, 128, 256, 384, 576, 800, 1600, 3200m3, the number of sampling points reduced from 2893 to 14. The ability of water interval sampling to capture peak runoff is obviously higher than that of time interval sampling. Load estimation error showed that the fluctuation of total phosphorus error is greater than that of total nitrogen error. Taking ±5% as the allowable error range, the effective time interval of rainfall runoff event sampling was 120min, and the effective water interval was 1600m3.
李影,秦丽欢,雷秋良,等.小流域农业面源污染监测断面设置与污染物通量估算研究进展[J]. 湖泊科学, 2022,34(5):1413-1427. Li Y, Qin L H, Lei Q L, et al. Review on agricultural non-point source pollution monitoring sections layout and pollutant loading estimation in small watershed [J]. Journal of Lake Sciences, 2022,34(5):1413-1427.
[2]
蒋锐,朱波,唐家良,等.紫色丘陵区典型小流域暴雨径流氮磷迁移过程与通量[J]. 水利学报, 2009,40(6):659-666. Jiang R, Zhu B, Tang J L, et al. Transportation processes and loss fluxes of nitrogen and phosphorous through storm runoff in a typical small watershed in the hilly area of purple soft [J]. Journal of Hydraulic Engineering, 2009,40(6):659-666.
[3]
Carpenter S R, Booth E G, Kucharik C J, et al. Extreme daily loads:role in annual phosphorus input to a north temperate lake [J]. Aquatic Sciences, 2015,77:71-79.
[4]
Littlewood I G. Hydrological regimes, sampling strategies, and assessment of errors in mass load estimates for United Kingdom rivers [J]. Environment International, 1995,21(2):211-220.
[5]
Vanni M J, Renwick W H, Headworth J L, et al. Dissolved and particulate nutrient flux from three adjacent agricultural watersheds:a five-year study [J]. Biogeochemistry, 2001,54:85-114.
[6]
Jiang R, Woli K P, Kuramochi K, et al. Hydrological process controls on nitrogen export during storm events in an agricultural watershed [J]. Soil Science & Plant Nutrition, 2010,56(1):72-85.
[7]
Gao P, Josefson M. Temporal variations of suspended sediment transport in Oneida Creek watershed, central New York [J]. Journal of Hydrology, 2012,426:17-27.
[8]
Horowitz A J. A review of selected inorganic surface water quality-monitoring practices:are we really measuring what we think, and if so, are we doing it right? [J]. Environmental science & technology, 2013,47(6):2471-2486.
[9]
徐光志,邵志江,汪涛,等.川中丘陵区不同下垫面集水区氮磷流失特征[J]. 中国环境科学, 2022,42(7):3334-3342. Xu Z G, Shao Z J, Wang T, et al. Patterns of nitrogen and phosphorus losses in two catchments with contrasting underlying surfaces [J]. China Environmental Science, 2022,42(7):3334-3342.
[10]
Moatar F, Meybeck M. Compared performances of different algorithms for estimating annual nutrient loads discharged by the eutrophic River Loire [J]. Hydrological Processes:An International Journal, 2005,19(2):429-444.
[11]
Li Y, Yen H, Harmel R D, et al. Effects of sampling strategies and estimation algorithms on total nitrogen load determination in a small agricultural headwater watershed [J]. Journal of Hydrology, 2019,579:124114.
[12]
李航,王毅,宋立芳,等.中亚热带典型农业小流域氮素输出特征及监测采样频率研究[J]. 环境科学学报, 2014,34(10):2668-2674. Li H, Wang Y, Song L F, et al. Nitrogen export characteristics and sampling frequency for nitrogen monitoring from a typical small agricultural catchment in central subtropics [J]. Acta Scientiae Circumstantiae, 2014,34(10):2668-2674.
[13]
Horowitz A J, Clarke R T, Merten G H. The effects of sample scheduling and sample numbers on estimates of the annual fluxes of suspended sediment in fluvial systems [J]. Hydrological Processes, 2015,29(4):531-543.
[14]
Harmel R D, King K W, Slade R M. Automated storm water sampling on small watersheds [J]. Applied Engineering in Agriculture, 2003, 19(6):667.
[15]
Horowitz A J. Determining annual suspended sediment and sediment-associated trace element and nutrient fluxes [J]. Science of the Total Environment, 2008,400(1-3):315-343.
[16]
Harmel R D, King K W, Haggard B E, et al. Practical guidance for discharge and water quality data collection on small watersheds [J]. Transactions of the ASABE, 2006,49(4):937-948.
[17]
King K W, Harmel R D, Fausey N R. Development and sensitivity of a method to select time-and flow-paced storm event sampling intervals for headwater streams [J]. Journal of Soil and Water Conservation, 2005,60(6):323-330.
[18]
King K W, Harmel R D. Comparison of time-based sampling strategies to determine nitrogen loading in plot-scale runoff [J]. Transactions of the ASAE, 2004,47(5):1457.
[19]
Ackerman D, Stein E D, Ritter K J. Evaluating performance of stormwater sampling approaches using a dynamic watershed model [J]. Environmental monitoring and assessment, 2011,180(1):283-302.
[20]
Robertson D M. Influence of different temporal sampling strategies on estimating total phosphorus and suspended sediment concentration and transport in small streams [J]. JAWRA Journal of the American Water Resources Association, 2003,39(5):1281-1308.
[21]
于兴修,李振炜,刘前进,等.沂蒙山区典型小流域降雨径流的磷素输出特征[J]. 环境科学, 2012,33(8):2644-2651. Yu X X, Li Z W, Liu Q J, et al. Output characteristics of rainfall runoff phosphorus pollution from a typical small watershed in Yimen~Mountainous area [J]. Environmental Science, 2012,33(8):2644-2651.
[22]
井光花,于兴修,刘前进,等.基于过程监测的典型小流域径流氮磷含量变化特征分析[J]. 农业环境科学学报, 2012,31(1):172-178. Jing G H, Yu X X, Liu Q J, et al. Variation characteristics of nitrogen and phosphorus contents in runoff water based on process monitoring in typical small watershed [J]. Journal of Agro-Environment Science, 2012,31(1):172-178.
[23]
王甜,肖文发,黄志霖,等.三峡库区紫色土坡地典型暴雨径流氮磷流失特征[J]. 生态与农村环境学报, 2022,38(3):367-374. Wang T, Xiao W F, Huang Z L, et al. Characteristics of typical rainstorm-runoff nitrogen and phosphorus loss on purple soil slope in Three Gorges Reservoir area [J]. Journal of Ecology and Rural Environment, 2022,38(3):367-374.
[24]
Hooper R P, Aulenbach B T, Kelly V J. The national stream quality accounting network:a flux-based approach to monitoring the water quality of large rivers [J]. Hydrological Processes, 2001,15(7):1089-1106.
[25]
Harmel R D, King K W, Wolfe J E, et al. Minimum flow considerations for automated storm sampling on small watersheds [J]. Texas Journal of Science, 2002,54(2):177-188.
[26]
Jefferson A J, Bhaskar A S, Hopkins K G, et al. Stormwater management network effectiveness and implications for urban watershed function:A critical review [J]. Hydrological Processes, 2017,31(23):4056-4080.
[27]
Chaudhary S, Chua L H C, Kansal A. Event mean concentration and first flush from residential catchments in different climate zones [J]. Water Research, 2022,219:118594.
[28]
Longabucco P, Rafferty M R. Analysis of material loading to Cannonsville Reservoir:advantages of event-based sampling [J]. Lake and Reservoir Management, 1998,14(2/3):197-212.
[29]
Kovács J, Korponai J, Kovács I S, et al. Introducing sampling frequency estimation using variograms in water research with the example of nutrient loads in the Kis-Balaton Water Protection System (W Hungary) [J]. Ecological engineering, 2012,42:237-243.
[30]
Kelly P T, Vanni M J, Renwick W H. Assessing uncertainty in annual nitrogen, phosphorus, and suspended sediment load estimates in three agricultural streams using a 21-year dataset [J]. Environmental monitoring and assessment, 2018,190:1-18.
[31]
Jones A S, Horsburgh J S, Mesner N O, et al. Influence of sampling frequency on estimation of annual total phosphorus and total suspended solids loads [J]. JAWRA Journal of the American Water Resources Association, 2012,48(6):1258-1275.
