Interactive effects of climate and land management on water quality in New Zealand rivers

Land cover change is heavily influenced by climate and land management. In places where the land is managed intensively and the climate is highly variable, interactions between these two variables can produce dramatic land cover changes over very short periods, daily in some cases. Given that rivers collect runoff from landscapes, these frequent and intense land cover changes can have considerable impacts on river water quality. A great place to study these landscape dynamics is New Zealand because (1) it has a highly variable climate over both space and time, (2) it has a wide variety and extent of management intensive land uses such as plantation forestry and rotational livestock grazing, (3) it has one of the most comprehensive and consistent water quality datasets in the world, and (4) its political boundaries coincide with watershed/catchment boundaries, which makes it easier to assess some of the political and socio-economic drivers of land use changes. Thus, we are using New Zealand as a case study to investigate how water quality is affected by interactions between climate and land management at fine spatial (30 meter) and temporal (8 day) resolutions. We are currently in the process of creating this 8-day, 30-meter land cover dataset for the entire country of New Zealand using novel and advanced remote sensing techniques.

Strip grazing (upper-left) and plantation forestry (bottom-right) in New Zealand.




NSF Geography and Spatial Sciences, Jason Julian (PI) with Kirsten de Beurs (PI) and Chris Weaver (co-I), 2014-2017.

NASA Land Cover Land Use Change Program, Jason Julian (PI) and Kirsten de Beurs (co-PI), 2013-2015.

Fulbright Scholar Program, Jason Julian (PI), 2012.



Julian JP, Davies-Colley RJ, Gallegos CL, Tran TV.  2013.  Optical water quality of inland waters: A landscape perspective.  Annals of the Association of American Geographers 103: 309-318.