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dc.contributor.authorLiu, Wenbaoen
dc.date2012-12-31 22:37:39.137
dc.date.accessioned2013-01-04T17:01:18Z
dc.date.issued2013-01-04
dc.identifier.urihttp://hdl.handle.net/1974/7715
dc.descriptionThesis (Ph.D, Geography) -- Queen's University, 2012-12-31 22:37:39.137en
dc.description.abstractThis dissertation is an empirical modeling investigation of the impact of forest harvesting, climate change and topography on stream nitrate fluxes in the Turkey Lakes Watershed (TLW), Ontario, Canada. Data used for this study include topography (DEM), climate (mean monthly temperature and total monthly precipitation), wet nitrogen deposition (total monthly nitrate-N and ammonium-N), nitrate water samples and streamflow in 13 headwater catchments within the TLW. First, a paired-watershed approach was used to examine the impact of forest harvesting intensity on stream water nitrate fluxes by developing transfer function noise (TFN) models that related monthly stream water nitrate fluxes of three treatment catchments to those of one control catchment. Second, TFN models were also developed to relate monthly stream nitrate fluxes in 13 catchments to the temperature, precipitation and wet nitrogen deposition to examine the spatially varying responses of stream nitrate fluxes to changes in climate and bulk deposition. Third, geographically weighted regression (GWR) was introduced to model the spatial and temporal relationships between topography and stream nitrate fluxes in 13 headwater catchments. The results showed that there existed a new phenomenon of clustered wave-up and wave-down of the stream nitrate increases caused by clearcut and selectioncut at the monthly scale, respectively. This phenomenon was never reported by previous studies because it was not possible to be identified with ordinary least squares (OLS) regression at an annual scale. There also existed significant responses of stream nitrate fluxes to wet nitrogen deposition in all catchments at the monthly scale over a long-term record between 1982 and 2003. These responses were previously thought to be lower and masked by the impact of climate variations. There further existed significant spatial and seasonal variability of the relationships between topography and stream nitrate fluxes across space and over time. This variability was largely ignored in previous studies with possibly misleading interpretation on the empirical relations.en
dc.language.isoengen
dc.relation.ispartofseriesCanadian thesesen
dc.rightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.en
dc.subjectTime seriesen
dc.subjectClimate changeen
dc.subjectTrend detectionen
dc.subjectTopographyen
dc.subjectGWR modelen
dc.subjectTFN modelen
dc.subjectWetlanden
dc.subjectForest harvesten
dc.subjectStream nitrate fluxen
dc.titleSpatiotemporal Modeling of the Impacts of Forest Harvesting, Climate Change and Topography on Stream Nitrates in a Forested Watersheden
dc.typethesisen
dc.description.restricted-thesisThis dissertation is being organized into 4 manuscripts for journal publications. Some journals of this research area do not accept materials that have been already available for public access, such as in a digital format of thesis. For this reason, I prefer to restrict this dissertation for 5 –years from online digital publication.en
dc.description.degreePhDen
dc.contributor.supervisorChen, Dongmeien
dc.contributor.departmentGeographyen
dc.embargo.terms1825en
dc.embargo.liftdate2018-01-03
dc.degree.grantorQueen's University at Kingstonen


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