Research

Research Areas

The Influence of Internal Climate Variability and External Forcing on Hydroclimatic Extremes

Increases in the intensity and frequency of hydroclimatic extremes associated with climate and land use/land cover (LULC) changes can cause significant socioeconomic consequences. Our research team develops novel frameworks to assess the projected impacts of extreme events on the environmental and hydrologic variables, and quantify the contribution of Internal Climate Variability (ICV) and anthropogenic factors to the future changes of extremes. Our research takes advantage of the growing hydroclimate observations and simulations including ground-based, remotely sensed and reanalysis data as well as global/regional climate simulations.

Integrated Approach for Flood Risk Assessment

Effective mitigation and adaptation measures for flood and erosion prevention and management require the development of reliable flood risk assessment frameworks. Our research group integrates statistical and physically-based approaches to characterize and predict the impacts of different flood drivers that can interact in space and time and quantify the corresponding uncertainties. We develop probabilistic frameworks to assess the impacts of compound flooding under climate change and characterize the corresponding risks considering the interrelationships between infrastructure assets. This research requires a high level of integration of multiple disciplines including climate change science, hydrology, hydraulics, risk assessment and statistics.

Characterizing the Nonstationary Compound Events

Changes in the regional characteristics of hydroclimate variables and their interdependencies can intensify the frequency and severity of extreme events such as rain-on-snow induced flooding, droughts, and wildfires. Analyzing these components in isolation can result in an underestimation of their combined effects. Our research group develops and applies novel multivariate statistical approaches to characterize the joint behaviour of multiple hazard components at different spatial and temporal scales, quantify the historical and future changes of the dependence structure, assess the propagation of univariate and bivariate biases into streamflow simulations, and develops statistical methods to quantify the non-stationary compound weather-related extreme events under climate change.

Evaluation and Bias Correction of Satellite and Radar Data

In-situ precipitation observations are scattered particularly at sub-daily scales, while reanalysis products show errors in the timing and location of intense precipitation. Radar and satellite data can provide a high-resolution estimate of precipitation providing the opportunity to analyze weather-related hazards more accurately. However, such products have problems associated with their indirect precipitation retrievals. Our goal is to generate reliable high-resolution precipitation data for flood forecasting and risk assessment, particularly for urban domains. We develop state-of-the-art techniques to bias-correct and blend recently generated remotely sensed products.

Detection and Attribution of Climate Change

We study the historical spatial and temporal patterns of hydroclimate variables and quantify the anthropogenic contributions, caused by human-induced greenhouse gas emissions, to the observed changes. This includes characterizing the separate contributions from greenhouse gases and sulfate aerosols to the Arctic temperature rise, the effects of anthropogenic forcing factors on the declining trends of spring snow cover extent in the Northern Hemisphere, and the anthropogenic forcing influence on the regional warming trends, snowpack reductions, and summer streamflow declines in Northwestern North America.

Risk and Resilience Assessment of Interconnected Infrastructure Systems

Societies around the world are facing natural hazards that are diverse, nonstationary, and can interact in space and time. The concurrent occurrence of multiple hazards and their compounding impacts can damage or disrupt the functionality of critical infrastructure systems leading to the disruptions of essential services. The failure of critical infrastructure extends the impacts of disasters beyond the original region. To prevent catastrophic infrastructure failures and mitigate damages, it is critical to identify the interrelationships among assets and the pathways of possible failures. Our group aims to develop multi-hazard risk and resilience analysis frameworks that go beyond the simple overlay of single hazards by considering the interactions between multiple hazards (coincidence, triggering secondary hazards, human activities exacerbating natural hazards) and cascading effects of critical infrastructure.

Grants and Projects

NSERC Alliance Grant, An Integrated Risk Assessment Framework for Compound Flooding (PI), 2020-2022.
NSERC Discovery Grant, Improved Characterization of Hydroclimatic Extremes through the Development of a Comprehensive Nonstationary Modelling Framework (PI), 2017-2022.
Western Interdisciplinary Development Initiatives Program, Climate Change, Sustainable Food Systems and Health Nexus (CoPI), 2021-2023.
NSERC-FRQNT, Novel numerical simulation tools for the vulnerability assessment and rehabilitation of critical structures against the effects of floods and climate change (CoPI), 2021-2022.
Canadian Queen Elizabeth II Diamond Jubilee Scholarships (QES), Building Research and Knowledge Translation Capacity for Climate Change Resilience, Food Security and Sustainable Livelihoods in West Africa (CoPI), 2020-2023.
Southern Ontario Smart Computing Innovation Platform (SOSCIP), Smart Computing for Compound Flooding in Canadian Urban Environments (PI), 2021-2022.
eCampusOntario (Virtual Learning Strategy), Engineering in a Changing Climate – A Transdisciplinary Workshop Series for Engineering and Climate Science Students (CoPI), 2021-2022.
Canadian Queen Elizabeth II Diamond Jubilee Scholarships (QES), Scholars Network for Building Disaster Resilient Communities (CoPI), 2020-2022.
Western Interdisciplinary Development Initiatives Program, Multi-hazard Risk and Resilience (CoPI), 2019-2022.
Environment and Climate Change Canada, Analysis of Hydro-Climatic Variables Affecting Extreme Maximum Flow in the Lake Winnipeg Watershed (PI), 2020-2021.
Institute for Catastrophic Loss Reduction (ICLR), Assessing the Impact of Cloud Seeding on Hail Damage in Alberta (CoPI), 2020-2021.
Ontario Centres of Excellence (VIP), Technology Advancement of Articulated Concrete Blocks Considering Improved Riverbed Stability and Seepage Erosion Control (PI), 2020-2021.
NSERC Collaborative Research and Development Grant, An Integrated Top-Down and Bottom-Up Approach to Assess and Mitigate River Flood Risks under Climate and Land-Use Change (PI), 2018-2020.
Ontario Centres of Excellence (Voucher for Innovation and Productivity I), Developing applicable technological strategies to increase water confidence in First Nations communities (PI), 2018-2019.
NSERC Engage, Evaluate, bias-correct and merge remotely sensed radar and satellite precipitation products over southern Canada (PI), 2019.
NDVIA (GPU Grant), Flood modelling using GPU's parallel computing (PI), 2019.
NSERC Engage, A Novel Probabilistic Flood Modelling Framework to Improve Infrastructure Resilience (PI), 2018-2018.
U.S.- Pakistan Center for Advanced Studies in Water, Uncertainties in Projected Impacts of Climate Change on Precipitation Patterns in the Indus Basin, Pakistan (CoPI), 2015-2016.

M. Reza Najafi

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