Sammanfattning

Lake Simcoe is the most important inland lake in Southern Ontario. The watershed is predominantly agricultural and under increasing pressure from urbanization, leading to changing runoff patterns in rivers draining to the lake. Uncertainties in rainfall-runoff modeling in tributary catchments of the Lake Simcoe Watershed (LSW) can be an order of magnitude larger than pristine watersheds, hampering water quality predictions and export calculations. Here we conduct a robust assessment to constrain the uncertainty in hydrological simulations and projections in the LSW using two representative adjacent agricultural catchments. Downscaled CGCM 3 projections using Al B and A2 emission scenarios projected increases of 4 C in air temperature and a 26% longer growing season. The fraction of precipitation falling as snow will decrease. Spring runoff is an important event in LSW but individual HBV best calibrated parameter sets under-predicted peak flows by up to 32%. Using an ensemble of behavioral parameter sets achieved credible representations of present day hydrology and constrained uncertainties in future projections. Parameter uncertainty analysis showed that the catchments differ in terms of their snow accumulation/melt and groundwater dynamics. Human activities exacerbate the differences in hydrological response. Model parameterization in one catchment could not generate credible hydrological simulations in the other. We cautioned against extrapolating results from monitored to ungauged catchments in managed watersheds like the LSW. (c) 2013 Elsevier B.V. All rights reserved.

Nyckelord

Statistical downscaling; Phenology; Climate change; Lake Simcoe; Hydrological change; Uncertainty analysis

Publicerad i

Science of the Total Environment
2014, Volym: 473, sidor: 326-337
Utgivare: ELSEVIER SCIENCE BV

SLU författare

• Oni, Stephen

  • Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
    
  • Trent University

• Futter, Martyn

  • Institutionen för vatten och miljö, Sveriges lantbruksuniversitet
    
  • Trent University

Globala målen

SDG6 Säkerställa tillgången till och en hållbar förvaltning av vatten och sanitet för alla
SDG13 Vidta omedelbara åtgärder för att bekämpa klimatförändringarna och dess konsekvenser
SDG11 Göra städer och bosättningar inkluderande, säkra, motståndskraftiga och hållbara


UKÄ forskningsämne

Miljö- och naturvårdsvetenskap


Publikationens identifierare

DOI: https://doi.org/10.1016/j.scitotenv.2013.12.032

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/53616