River water quality changes in New Zealand over 26 years: response to land use intensity

Julian, Jason P.; de Beurs, Kirsten M.; Owsley, Braden; Davies-Colley, Robert J.; Ausseil, Anne-Gaelle E.

doi:https://doi.org/10.5194/hess-21-1149-2017

Articles | Volume 21, issue 2

https://doi.org/10.5194/hess-21-1149-2017

© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.

https://doi.org/10.5194/hess-21-1149-2017

© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.

Articles | Volume 21, issue 2

Research article

|

23 Feb 2017

Research article |

| 23 Feb 2017

River water quality changes in New Zealand over 26 years: response to land use intensity

Jason P. Julian, Kirsten M. de Beurs, Braden Owsley, Robert J. Davies-Colley, and Anne-Gaelle E. Ausseil

Supplement

https://doi.org/10.5194/hess-21-1149-2017-supplement

Data sets

Twenty years of New Zealand's National Rivers Water Quality Network: Benefits of careful design and consistent operation (https://niwa.co.nz/freshwater/water-quality-monitoring-and-advice/national-river-water-quality-network-nrwqn) R. J. Davies-Colley, D. G. Smith, R. C. Ward, G. G. Bryers, G. B. McBride, J. M. Quinn, and M. R. Scarsbrook https://doi.org/10.1111/j.1752-1688.2011.00554.x

New Zealand Disturbance K. M. de Beurs http://tethys.dges.ou.edu/NZ_disturbance/#

Short summary

New Zealand is a natural laboratory for investigating water quality responses to land use intensity because it has one of the highest rates of agricultural intensification globally over recent decades. We interpreted water quality state and trends (1989–2014) of 77 river sites across NZ. We show that the greatest long-term negative impacts on river water quality have been increased cattle densities and legacy nutrients from intensively managed grasslands and plantation forests.