| [1] |
Gruber N, Galloway JN. 2008. An Earth-system perspective of the global nitrogen cycle. |
| [2] |
Yan X, Shan J, Wang X, Wang B, Liu S, et al. 2025. Uncovering the soil nitrogen cycle from microbial pathways to global sustainability. |
| [3] |
Khalid B, Ikram M, Batool M, Ullah M, Wang X, et al. 2026. Optimizing nitrogen use in rapeseed systems: a global meta-analysis of yield gains and environmental trade-offs. |
| [4] |
Schulte-Uebbing LF, Beusen AHW, Bouwman AF, de Vries W. 2022. From planetary to regional boundaries for agricultural nitrogen pollution. |
| [5] |
Sutton MA, Oenema O, Erisman JW, Leip A, van Grinsven H, et al. 2011. Too much of a good thing. |
| [6] |
Yan YG, Zhang S, Zhang Y, Xu M, Xu J, et al. 2025. Spatial divergence of nitrogen fate in China's wheat systems: a meta-analysis and machine-learning roadmap for region-specific management. |
| [7] |
Sinha E, Michalak AM, Balaji V. 2017. Eutrophication will increase during the 21st century as a result of precipitation changes. |
| [8] |
Liu HT, Hou JY, Deng M, Sun ZG. 2025. Characteristics and influencing factors of livestock residue nitrogen, phosphorus, and organic matter discharge and spatial distribution of pollution potential: case study in the Yellow River Delta, China. |
| [9] |
Cheng M, Quan J, Yin J, Liu X, Yuan Z, et al. 2023. High-resolution maps of intensive and extensive livestock production in China. |
| [10] |
Bianchi TS, DiMarco SF, Cowan JH Jr, Hetland RD, Chapman P, et al. 2010. The science of hypoxia in the Northern Gulf of Mexico: a review. |
| [11] |
Díaz RJ, Rosenberg R. 2011. Introduction to environmental and economic consequences of hypoxia. |
| [12] |
Chen X, Wang M, Kroeze C, Chen X, Ma L, et al. 2022. Nitrogen in the Yangtze River basin: pollution reduction through coupling crop and livestock production. |
| [13] |
Gannon JP, Bailey SW, McGuire KJ. 2014. Organizing groundwater regimes and response thresholds by soils: a framework for understanding runoff generation in a headwater catchment. |
| [14] |
Vereecken H, Amelung W, Bauke SL, Bogena H, Brüggemann N, et al. 2022. Soil hydrology in the Earth system. |
| [15] |
Shen W, Li S, Mi M, Zhuang Y, Zhang L. 2021. What makes ditches and ponds more efficient in nitrogen control? |
| [16] |
Chen S. 2025. Study on spatio-temporal distribution characteristics and source partitioning of dissolved organic nitrogen in Poyang Lake. Inner Mongolia Agricultural University, China. doi: 10.27229/d.cnki.gnmnu.2025.001250 |
| [17] |
Cameron KC, Di HJ, Moir JL. 2013. Nitrogen losses from the soil/plant system: a review. |
| [18] |
Biddau R, Dore E, Da Pelo S, Lorrai M, Botti P, et al. 2023. Geochemistry, stable isotopes and statistic tools to estimate threshold and source of nitrate in groundwater (Sardinia, Italy). |
| [19] |
Zanotti C, Rotiroti M, Fumagalli L, Stefania GA, Canonaco F, et al. 2019. Groundwater and surface water quality characterization through positive matrix factorization combined with GIS approach. |
| [20] |
O’Brien D, Markiewicz-Keszycka M, Herron J. 2023. Environmental impact of grass-based cattle farms: a life cycle assessment of nature-based diversification scenarios. |
| [21] |
Gassman PW, Reyes, MR, Green CH, Arnold JG. 2007. The soil and water assessment tool: historical development, applications, and future research directions. |
| [22] |
Davidson GR, Bassett RL. 1993. Application of boron isotopes for identifying contaminants such as fly ash leachate in groundwater. |
| [23] |
Ding Y, Song Z, Hu Y, Zhang S, Zhang M, et al. 2024. A review on curbing non-point source pollution in watershed − the answer lies at the root. |
| [24] |
Lin B, Qi F, An X, Zhao C, Gao Y, et al. 2026. Review: the application of source analysis methods in tracing urban non-point source pollution: categorization, hotspots, and future prospects. |
| [25] |
Wang W, Chen L, Lin C, Liu Y, Dong X, et al. 2023. Source appointment at large-scale and ungauged catchment using physically-based model and dynamic export coefficient. |
| [26] |
Xia Y, Li Y, Zhang X, Yan X. 2017. Nitrate source apportionment using a combined dual isotope, chemical and bacterial property, and Bayesian model approach in river systems. |
| [27] |
Liu CQ, Li SL, Lang YC, Xiao HY. 2006. Using δ15N- and δ18O-values to identify nitrate sources in karst ground water, Guiyang, southwest China. |
| [28] |
Yi Q, Chen Q, Hu L, Shi W. 2017. Tracking nitrogen sources, transformation, and transport at a basin scale with complex plain river networks. |
| [29] |
Xue D, De Baets B, Van Cleemput O, Hennessy C, Berglund M, et al. 2012. Use of a Bayesian isotope mixing model to estimate proportional contributions of multiple nitrate sources in surface water. |
| [30] |
Anisfeld SC, Barnes RT, Altabet MA, Wu T. 2007. Isotopic apportionment of atmospheric and sewage nitrogen sources in two Connecticut rivers. |
| [31] |
Tan ML, Gassman PW, Yang X, Haywood J. 2020. A review of SWAT applications, performance and future needs for simulation of hydro-climatic extremes. |
| [32] |
Chen W, Wan Y, Guo Y, Ji G, Shi L. 2025. Predicting non-point source pollution in Henan province using the diffuse pollution estimation with remote sensing model with enhanced sensitivity analysis. |
| [33] |
Zhang Y, He X, Lian G, Bai Y, Yang Y, et al. 2023. Monitoring and spatial traceability of river water quality using Sentinel-2 satellite images. |
| [34] |
Panno SV, Hackley KC, Hwang HH, Kelly WR. 2001. Determination of the sources of nitrate contamination in karst springs using isotopic and chemical indicators. |
| [35] |
Bassett RL, Buszka PM, Davidson GR, Chong-Diaz D. 1995. Identification of groundwater solute sources using boron isotopic composition. |
| [36] |
Ministry of Environmental Protection. 2002. Environmental quality standards for surface water. GB 3838. Ministry of Environmental Protection, China. www.mee.gov.cn/ywgz/fgbz/bz/bzwb/shjbh/shjzlbz/200206/t20020601_66497.shtml |
| [37] |
Seiler RL. 2005. Combined use of 15N and 18O of nitrate and 11B to evaluate nitrate contamination in groundwater. |
| [38] |
Lang YC, Liu CQ, Zhao ZQ, Li SL, Han GL. 2006. Geochemistry of surface and ground water in Guiyang, China: water/rock interaction and pollution in a karst hydrological system. |
| [39] |
Widory D, Kloppmann W, Chery L, Bonnin J, Rochdi H, et al. 2004. Nitrate in groundwater: an isotopic multi-tracer approach. |
| [40] |
Widory D, Petelet-Giraud E, Négrel P, Ladouche B. 2005. Tracking the sources of nitrate in groundwater using coupled nitrogen and boron isotopes: a synthesis. |
| [41] |
Barth S. 1998. Application of boron isotopes for tracing sources of anthropogenic contamination in groundwater. |
| [42] |
Komor SC. 1997. Boron contents and isotopic compositions of hog manure, selected fertilizers, and water in Minnesota. |
| [43] |
Vengosh A, Barth S, Heumann KG, Eisenhut S. 1999. Boron isotopic composition of freshwater lakes from central Europe and possible contamination sources. |
| [44] |
Négrel P, Deschamps P. 1996. Natural and anthropogenic budgets of a small watershed in the massif central (France): chemical and strontium isotopic characterization of water and sediments. |
| [45] |
Mariotti A, Landreau A, Simon B. 1988. 15N isotope biogeochemistry and natural denitrification process in groundwater: application to the chalk aquifer of northern France. |
| [46] |
Crowther J, Kay D, Wyer MD. 2002. Faecal-indicator concentrations in waters draining lowland pastoral catchments in the UK: relationships with land use and farming practices. |
| [47] |
Soupir ML, Mostaghimi S, Yagow ER, Hagedorn C, Vaughan DH. 2006. Transport of fecal bacteria from poultry litter and cattle manures applied to pastureland. |
| [48] |
Eckner KF. 1998. Comparison of membrane filtration and multiple-tube fermentation by the colilert and enterolert methods for detection of waterborne coliform bacteria, Escherichia coli, and Enterococci used in drinking and bathing water quality monitoring in southern Sweden. |
| [49] |
Gronewold AD, Wolpert RL. 2008. Modeling the relationship between most probable number (MPN) and colony-forming unit (CFU) estimates of fecal coliform concentration. |
| [50] |
Kistemann T, Claßen T, Koch C, Dangendorf F, Fischeder R, et al. 2002. Microbial load of drinking water reservoir tributaries during extreme rainfall and runoff. |
| [51] |
Arana I, Muela A, Orruño M, Seco C, Garaizabal I, et al. 2010. Effect of temperature and starvation upon survival strategies of Pseudomonas fluorescens CHA0: comparison with Escherichia coli. |
| [52] |
Pachepsky YA, Blaustein RA, Whelan G, Shelton DR. 2014. Comparing temperature effects on Escherichia coli, Salmonella, and Enterococcus survival in surface waters. |
| [53] |
Pardo LH, Kendall C, Pett-Ridge J, Chang CCY. 2004. Evaluating the source of streamwater nitrate using δ15N and δ18O in nitrate in two watersheds in New Hampshire, USA. |
| [54] |
Townsend-Small A, McCarthy MJ, Brandes JA, Yang L, Zhang L, et al. 2007. Stable isotopic composition of nitrate in Lake Taihu, China, and major inflow rivers. |
| [55] |
Xue D, Botte J, De Baets B, Accoe F, Nestler A, et al. 2009. Present limitations and future prospects of stable isotope methods for nitrate source identification in surface- and groundwater. |
| [56] |
Chen F, Jia G, Chen J. 2009. Nitrate sources and watershed denitrification inferred from nitrate dual isotopes in the Beijiang River, south China. |
| [57] |
Li SL, Liu CQ, Li J, Liu X, Chetelat B, et al. 2010. Assessment of the sources of nitrate in the Changjiang river, China using a nitrogen and oxygen isotopic approach. |
| [58] |
Kellman LM, Hillaire-Marcel C. 2003. Evaluation of nitrogen isotopes as indicators of nitrate contamination sources in an agricultural watershed. |
| [59] |
Kendall C. 1998. Tracing nitrogen sources and cycling in catchments. In Isotope Tracers in Catchment Hydrology, ed. McDonnell JJ. Amsterdam: Elsevier. pp. 519–576 doi: 10.1016/b978-0-444-81546-0.50023-9 |
| [60] |
Divers MT, Elliott EM, Bain DJ. 2014. Quantification of nitrate sources to an urban stream using dual nitrate isotopes. |
| [61] |
Singh KP, Malik A, Sinha S. 2005. Water quality assessment and apportionment of pollution sources of Gomti river (India) using multivariate statistical techniques − a case study. |
| [62] |
Haji Gholizadeh M, Melesse AM, Reddi L. 2016. Water quality assessment and apportionment of pollution sources using APCS-MLR and PMF receptor modeling techniques in three major rivers of South Florida. |
| [63] |
Mao H, Wang G, Liao F, Shi Z, Zhang H, et al. 2023. Spatial variability of source contributions to nitrate in regional groundwater based on the positive matrix factorization and Bayesian model. |
| [64] |
Johnes PJ. 1996. Evaluation and management of the impact of land use change on the nitrogen and phosphorus load delivered to surface waters: the export coefficient modelling approach. |
| [65] |
Vassiljev A, Blinova I, Ennet P. 2008. Source apportionment of nutrients in Estonian rivers. |
| [66] |
Yuan Z, Pang Y, Gao J, Liu X, Sheng H, et al. 2021. Improving quantification of rainfall runoff pollutant loads with consideration of path curb and field ridge. |
| [67] |
Minet EP, Goodhue R, Meier-Augenstein W, Kalin RM, Fenton O, et al. 2017. Combining stable isotopes with contamination indicators: a method for improved investigation of nitrate sources and dynamics in aquifers with mixed nitrogen inputs. |
| [68] |
Panno SV, Hackley KC, Kelly WR, Hwang HH. 2006. Isotopic evidence of nitrate sources and denitrification in the Mississippi River, Illinois. |
| [69] |
Fukada T, Hiscock KM, Dennis PF, Grischek T. 2003. A dual isotope approach to identify denitrification in groundwater at a river-bank infiltration site. |
| [70] |
Zhang L, Hu Y, Wang J, Zhang M. 2021. Effects of fertilization on the composition of δ15N in soil, vegetables and runoff of vegetable field. |
| [71] |
Parnell AC, Inger R, Bearhop S, Jackson AL. 2010. Source partitioning using stable isotopes: coping with too much variation. |
| [72] |
Sun C, Chen L, Liu HB, Zhu H, Lü MQ, et al. 2021. New modeling framework for describing the pollutant transport and removal of ditch-pond system in an agricultural catchment. |
| [73] |
Young RA, Onstad CA, Bosch DD, Anderson WP. 1989. AGNPS: a nonpoint-source pollution model for evaluating agricultural watersheds. |
| [74] |
Abbaspour KC, Rouholahnejad E, Vaghefi S, Srinivasan R, Yang H, et al. 2015. A continental-scale hydrology and water quality model for Europe: calibration and uncertainty of a high-resolution large-scale SWAT model. |
| [75] |
Adu JT, Kumarasamy MV. 2018. Assessing non-point source pollution models: a review. |
| [76] |
Zhuang Y, Liu X, Yuan Z, Sheng H, Gao J. 2023. A process-based model to track water pollutant generation at high resolution and its pathway to discharge. |
| [77] |
Fang S, Deitch MJ, Gebremicael TG, Angelini C, Ortals CJ. 2024. Identifying critical source areas of non-point source pollution to enhance water quality: integrated SWAT modeling and multi-variable statistical analysis to reveal key variables and thresholds. |
| [78] |
Zhu D, Cheng X, Li W, Niu F, Nayeb Yazdi M. 2023. Estimating the impact of temperature and streamflow change on river nitrogen pollution using the land-river integrated modeling system. |
| [79] |
Boithias L, Srinivasan R, Sauvage S, Macary F, Sánchez-Pérez JM. 2014. Daily nitrate losses: implication on long-term river quality in an intensive agricultural catchment of Southwestern France. |
| [80] |
Xue J, Wang Q, Zhang M. 2022. A review of non-point source water pollution modeling for the urban–rural transitional areas of China: research status and prospect. |
| [81] |
Alexander RB, Smith RA, Schwarz GE, Boyer EW, Nolan JV, et al. 2008. Differences in phosphorus and nitrogen delivery to the Gulf of Mexico from the Mississippi river basin. |
| [82] |
Xia Y, Zhao D, Yan X, Hu W, Qiu J, et al. 2023. A new framework to model the distributed transfer and retention of nutrients by incorporating topology structure of small water bodies. |
| [83] |
Beusen AHW, Van Beek LPH, Bouwman AF, Mogollón JM, Middelburg JJ. 2015. Coupling global models for hydrology and nutrient loading to simulate nitrogen and phosphorus retention in surface water – description of IMAGE–GNM and analysis of performance. |
| [84] |
Huang X, Yang X, Xie Y, Zhang H, Lu N, et al. 2025. Pathway-specific nitrogen export across a rural-urban gradient: integrating hydrograph separation and end-member mixing analysis. |
| [85] |
Husic A, Fox J, Adams E, Pollock E, Ford W, et al. 2020. Quantification of nitrate fate in a karst conduit using stable isotopes and numerical modeling. |
| [86] |
Husic A, Fox J, Adams E, Ford W, Agouridis C, et al. 2019. Nitrate pathways, processes, and timing in an agricultural karst system: development and application of a numerical model. |
| [87] |
Husic A, Fox J, Mahoney T, Gerlitz M, Pollock E, et al. 2020. Optimal transport for assessing nitrate source-pathway connectivity. |
| [88] |
Hao Z, Shi Y, Zhan X, Yu B, Fan Q, et al. 2024. Quantifying and assessing nitrogen sources and transport in a megacity water supply watershed: insights for effective non-point source pollution management with mixSIAR and SWAT models. |
| [89] |
Chen R, Shen W, Tong C, Guo J, Yang L, et al. 2024. Contrasting nitrogen transport patterns in subtropical basins revealed by combined multiple isotopic analyzes and hydrological simulations. |
| [90] |
Park M, Kim HM, Kim Y, Bak S, Kim TY, et al. 2024. A framework for detecting and managing non-point-source pollution in agricultural areas using GeoAI and UAVs. |
| [91] |
Redoloza FS, Williamson TN, Headman AO, Allred BJ. 2023. Machine-learning model to delineate sub-surface agricultural drainage from satellite imagery. |
| [92] |
Miller MP, Tesoriero AJ, Hood K, Terziotti S, Wolock DM. 2017. Estimating discharge and nonpoint source nitrate loading to streams from three end-member pathways using high-frequency water quality data. |
| [93] |
Wang J, Li X, Li Y, Shi Y, Xiao H, et al. 2024. Transport pathways of nitrate in stormwater runoff inferred from high-frequency sampling and stable water isotopes. |
| [94] |
Scholten C, Kottari M, Puerta Pereira J, Erven C, Garcia Gutierrez J, et al. 2025. The future of water availability and use in the EU: a foresight study and policy options to address water scarcity. European Union, Brussels, Belgium. www.europarl.europa.eu/thinktank/en/document/EPRS_STU(2025)765769 |