Multi-risk modeling for improved agriculture decision-support: predicting crop yield variability and gaps due to climate variability, extreme events, and disease

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dc.contributor.author Lu, Weixun
dc.date.accessioned 2020-09-16T02:52:42Z
dc.date.copyright 2020 en_US
dc.date.issued 2020-09-15
dc.identifier.uri http://hdl.handle.net/1828/12130
dc.description.abstract The agriculture sectors in Canada are highly vulnerable to a wide range of inter-related weather risks linked to seasonal climate variability (e.g., El Ni ̃no Southern Oscillation(ENSO)), short-term extreme weather events (e.g., heatwaves), and emergent disease(e.g., grape powdery mildew). All of these weather-related risks can cause severe crop losses to agricultural crop yield and crop quality as Canada grows a wide range of farm products, and the changing weather conditions mainly drive farming practices. This dissertation presents three machine learning-based statistical models to assess the weather risks on the Canadian agriculture regions and to provide reliable risk forecasting to improve the decision-making of Canadian agricultural producers in farming practices. The first study presents a multi-scale, cluster-based Principal Component Analysis(PCA) approach to assess the potential seasonal impacts of ENSO to spring wheat and barley on agricultural census regions across the Canada prairies areas. Model prediction skills for annual wheat and barley yield have examined in multi-scale from spatial cluster approaches. The ’best’ spatial models were used to define spatial patterns of ENSO forcing on wheat and barley yields. The model comparison of our spatial model to non-spatial models shows spatial clustering and ENSO forcing have increase model performance of prediction skills in forecasting future cereal crop production. The second study presents a copula-Bayesian network approach to assess the impact of extreme high-temperature events (heatwave events) on the developments of regional crops across the Canada agricultural regions at the eco-district-scale. Relevantweather variables and heatwave variables during heatwave periods have identified and used as input variables for model learning. Both a copula-Bayesian network and Gaussian-based network modeling approach is evaluated and inter-compared. The copula approach based on ’vine copulas’ generated the most accurate predictions of heatwave occurrence as a driver of crop heat stress. The last study presents a stochastic, hybrid-Bayesian machine-learning approach to explore the complex causal relationships between weather, pathogen, and host for grape powdery mildew in an experimental farm in Quebec, Canada. This study explores a high-performance network model for daily disease risk forecast by using estimated development factors of pathogen and host from recorded daily weather variables. A fungicide strategy for disease control has presented by using the model outputs and forecasted future weather variability. The dissertation findings are beneficial to Canada’s agricultural sector. The inter-related weather risks explored by the three separate studies in multi-scales provide a better understanding of the interactions between changing weather conditions, extreme weather, and crop production. The research showcases new insights, methods, and tools for minimizing risk in agricultural decision-making en_US
dc.language English eng
dc.language.iso en en_US
dc.rights Available to the World Wide Web en_US
dc.subject Bayesian learning networks en_US
dc.subject ENSO en_US
dc.subject Agriculture en_US
dc.subject Climate risk en_US
dc.subject Forecasting en_US
dc.subject Modeling en_US
dc.subject disease risk en_US
dc.subject Modeling en_US
dc.subject Forecasting en_US
dc.subject Powdery mildew disease en_US
dc.subject risk en_US
dc.subject Viticulture en_US
dc.subject principal component analysis en_US
dc.subject heatwave en_US
dc.subject heat stress en_US
dc.title Multi-risk modeling for improved agriculture decision-support: predicting crop yield variability and gaps due to climate variability, extreme events, and disease en_US
dc.type Thesis en_US
dc.contributor.supervisor Newlands, Nathaniel
dc.contributor.supervisor Atkinson, David E.
dc.degree.department Department of Geography en_US
dc.degree.level Doctor of Philosophy Ph.D. en_US
dc.identifier.bibliographicCitation Lu, W., Newlands, N. K., Carisse, O., Atkinson, D. E., & Cannon, A. J. (2020). Disease Risk Forecasting with Bayesian Learning Networks: Application to Grape Powdery Mildew (Erysiphe necator) in Vineyards. Agronomy, 10(5), 622. en_US
dc.identifier.bibliographicCitation Lu, W., Atkinson, D. E., & Newlands, N. K. (2017). ENSO climate risk: predicting crop yield variability and coherence using cluster-based PCA. Modeling Earth Systems and Environment, 3(4), 1343-1359. en_US
dc.description.scholarlevel Graduate en_US
dc.description.embargo 2021-08-19

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