Uncertainty assessments and hydrological implications of climate change in two adjacent agricultural catchments of a rapidly urbanizing watershed

Abstract

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.

Keywords

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

Published in

Science of the Total Environment
2014, volume: 473, pages: 326-337
Publisher: ELSEVIER SCIENCE BV

SLU Authors

• Oni, Stephen

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    
  • Trent University

• Futter, Martyn

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    
  • Trent University

Global goals (SDG)

SDG6 Clean water and sanitation
SDG11 Sustainable cities and communities
SDG13 Climate action

UKÄ Subject classification

Environmental Sciences and Nature Conservation

Publication identifier

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

Permanent link to this page (URI)

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