Influence of legacy phosphorus, land use, and climate change on anthropogenic phosphorus inputs and riverine export dynamics
- 641 Downloads
A quantitative understanding of riverine phosphorus (P) export in response to changes in anthropogenic P inputs (NAPI), land use and climate is critical for developing effective watershed P control measures. This study indicated that annual riverine TP export for the six catchments of the Yongan River watershed in eastern China increased 4.1–30.3-fold over the 1980–2010 period. Increased riverine TP export resulted from a 61–85 % increase in NAPI and a 2.6–14.6-fold increase in riverine export fraction of NAPI due to 36–43, 30–125, and 65–76 % increases in developed land area (D%), drained agricultural land area (DA%), and storm events, respectively. For the 31-year cumulative record, 1.6–14 % of NAPI was exported by rivers, 40–64 % was stored in the upper 20 cm of agricultural soils, and 30–55 % was retained in other landscape positions. An empirical model that incorporates annual NAPI, precipitation, D%, and DA% accounted for 94 % of the variation in annual riverine TP fluxes across the six catchments and 31 years. The model estimated that NAPI and legacy P contributed 42–92 % and 8–58 % of annual riverine TP flux, respectively. The model forecasts an 8–18 % increase in riverine TP flux by 2030 due to a 4 % increase in precipitation with no changes in NAPI and land use compared to the 2000–2010 baseline condition. Enhanced export of NAPI and legacy P by changes in land use and climate will delay the decrease in riverine P flux in response to NAPI reductions and should be considered in developing and assessing watershed P management strategies.
KeywordsPhosphorus Legacy nutrients Land use Nutrient budget Climate change Eutrophication
We thank the local government for providing data critical for this investigation. This work was supported by the National Natural Science Foundation of China (41371010), Zhejiang Provincial Natural Science Foundation of China (LY13D010002), and Chinese National Key Technology R&D Program (2012BAC17B01).
Conflict of interest
This study has no conflict of interest with any persons or affiliations.
- Bowes J, Jarviea HP, Naden PS, Old GH, Scarlett PM, Roberts C, Armstrong LK, Harman SA, Wickham HD, Collins AL (2014) Identifying priorities for nutrient mitigation using river concentration–flow relationships: the Thames basin, UK. J Hydrol 571:1–12. doi: 10.1016/j.jhydrol.2014.03.063 CrossRefGoogle Scholar
- Bundy LG, Sturgul SJ (2001) A phosphorus budget for Wisconsin cropland. J Soil Water Conserv 56:243–249Google Scholar
- Haygarth PM, Jarvie HP, Powers SM, Sharpley AN, Elser JJ, Shen JB, Peterson HM, Chan NI, Howden NJK, Burt T, Worrall F, Zhang FS, Liu XJ (2014) Sustainable phosphorus management and the need for a long-term perspective: the legacy hypothesis. Environ Sci Technol 48:8417–8419. doi: 10.1021/es502852 CrossRefGoogle Scholar
- Hong B, Swaney DP, Mörth C-M, Smedberg E, Hägg EH, Humborg C, Howarth RW, Bouraoui F (2012) Evaluating regional variation of net anthropogenic nitrogen and phosphorus inputs (NANI/NAPI), major drivers, nutrient retention pattern and management implications in the multinational areas of Baltic Sea basin. Ecol Model 227:117–135. doi: 10.1016/j.ecolmodel.2011.12.002 CrossRefGoogle Scholar
- Liu Y (2005) Phosphorus flows in China: physical profiles and environmental regulation. Dissertation, Wageningen UniversityGoogle Scholar
- Mo HX, Qiu HG, Wang JX, Bai JF (2011) Livestock and poultry excreta treatment and its influencing factors in China. Agro-environ Dev 28:59–64 (in Chinese with English abstract)Google Scholar
- PGZP (The People’s Government of Zhejiang Province) (2010) The response program for climate change of Zhejiang Province in China. Available online at: http://www.zj.gov.cn/art/2010/12/2/art_12460_7561.html. Accessed 26 June 2014
- Reddy KR, Clark MW, Nair VD (2012) Legacy phosphorus in agricultural watersheds: Implications for restoration and management of wetlands and aquatic systems. International atomic energy agency (IAEA) newsletter. Available online at: http://www-naweb.iaea.org/nafa/swmn/public/SNL-34-2.pdf. Accessed 26 June 2014
- Runkel RL, Crawford CG, Cohn TA (2004) Load estimator (loadest): a Fortran program for estimating constituent loads in streams and rivers. Available online at: http://pubs.usgs.gov/tm/2005/tm4A5/pdf/508final.pdf. Accessed 26 June 2014
- Sharpley AN, Kleinman PJA, McDowell RW, Gitau M, Bryant RB (2002) Modeling phosphorus transport in agricultural watersheds: processes and possibilities. J Soil Water Conserv 57:425–439Google Scholar
- Shen RP, Sun B, Zhao QG (2005) Spatial and temporal variability of N, P and K balances for agroecosystems in China. Pedosphere 15:347–355Google Scholar
- USEPA 2002. National management measures to control nonpoint source pollution from agriculture. Available online at: http://water.epa.gov/polwaste/nps/agriculture/agmm_index.cfm. Accessed 26 June 2014