Climatological, Hydrological, and Economic Analysis of Agriculture in Montana and the Western U.S.A.
Year of Award
2023
Document Type
Dissertation
Degree Type
Doctor of Philosophy (PhD)
Degree Name
Geosciences
Department or School/College
Geosciences
Committee Chair
Marco Maneta
Commitee Members
Kelly Cobourn, Kelsey Jencso, John S. Kimball, Bruce Maxwell, Andrew Wilcox
Keywords
agriculture, climate change, modeling, Montana, Western U.S.A., rainfed
Publisher
University of Montana
Subject Categories
Hydrology
Abstract
Many studies have addressed the impact of climate on agriculture; however, fewer studies addressed how farmers adapt to climate change, to what extent implementation of adaptation strategies mitigates economic losses or alters the hydrologic system. Analyses of how historical climate affected not only farmer decision making, but also the economic and hydrological consequences of farmers’ adaptations to climate variations, and projections of the spatiotemporal climatic regimes at finer regional scales are critical for aiding in actionable climate change adaptations. This dissertation helps fill knowledge gaps on the impacts of climate change in rural regions of the agricultural western U.S.A. and provides a baseline to understand what crops farmers in the region will prioritize under future climates, and what will be the economic and hydrologic costs of adaptation.
The first project modeled producer behavior under end-of-century climate projections. We applied a stochastic, integrated hydro-economic model that simulates land and water allocations to analyze Montana farmer adaptations to a range of projected climate conditions and the response of the hydrologic system to those adaptations. Results show a state-wide increase in agricultural water use leading to decreased summer streamflows. Land use for irrigated crops increased while rainfed crops decreased, implying state-level decrease in planted area. Both irrigated and rainfed crop production and farmer revenue decreased.
The second project used historical data to quantify the climate water deficit (CWD) threshold where farmers’ perception swings towards repurposing crops instead of harvesting for grain. We analyzed the relationship between crop repurposing (the ratio of acres harvested for grain to the total planted acres) to seasonal CWD, and to isolate the climate signal from economic factors, our analysis accounted for the influence of crop prices on grain harvest. Results indicate that farmers are less likely to harvest barley and spring wheat for grain when the spring CWD is above average. For the majority of major crop growing regions, grain prices increased with lower levels of grain harvest.
The third project used the most current climate change forecasts to predict future climate regimes of important rainfed winter wheat growing regions and compare current yields of climate analog regions. Using a suite of climate models, we evaluate which model(s) best simulated seasonal historical distributions of five climatic variables using the energy distance statistical metric, then use the best performing models to predict and map mid-century climate analog locations across the western U.S.A. Results show significant western and/or southern shifts in analog locations, regardless of season. These shifts to warmer, dryer regions do not conclusively imply decreased yields, however land use devoted to rainfed winter wheat in analog regions was dramatically lower.
Recommended Citation
Lauffenburger, Zachary H., "Climatological, Hydrological, and Economic Analysis of Agriculture in Montana and the Western U.S.A." (2023). Graduate Student Theses, Dissertations, & Professional Papers. 12219.
https://scholarworks.umt.edu/etd/12219
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© Copyright 2023 Zachary H. Lauffenburger