Understanding the impacts of policy and stakeholder behavior on watershed quality in the Midwest

Golub, Emma

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https://hdl.handle.net/2142/124442 Copy

Description

Title

Understanding the impacts of policy and stakeholder behavior on watershed quality in the Midwest

Author(s)

Golub, Emma

Issue Date

2024-04-30

Director of Research (if dissertation) or Advisor (if thesis)

Cai, Ximing

Department of Study

Civil & Environmental Eng

Discipline

Environ Engr in Civil Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• water quality
• nonpoint source pollution
• perennial energy grass
• FWEE
• CHNS
• best-management practices
• land-use change
• SWAT
• agent-based model
• nutrient reduction

Abstract

As a result of widespread and unregulated nonpoint source pollution (NPS), over half of the United States’ surface water bodies are impaired. Excessive nutrient concentrations from agricultural runoff exacerbate toxic algal blooms and eutrophication, which degrade ecosystem health and threaten human well-being. As a critical component of the food, water, energy, and environment (FWEE) nexus, adequate water quality protection necessitates a multi-perspective system approach. While previous research in optimizing agricultural best management practices (BMPs) and modeling watershed nutrient dynamics have provided valuable insight, such approaches often fail to consider their integration with policies and stakeholder perspectives, which influence how water management practices are implemented. To better understand how stakeholder (i.e., farmer, rural community, industry, and gov ernment) behaviors impact water quality, we couple an agent-based model (ABM) and the Soil Water Assessment Tool (SWAT) across several policy scenarios. Examining Illinois’ Upper Sangamon River Basin amidst a lagging cellulosic biofuel economy, we explore how land-use change decisions like the adoption of perennial energy grasses (i.e., miscanthus) in the Midwest can affect water quality. Compared to a “business-as-usual” policy baseline, we illustrate how a scenario that combines environmental and biofuel policy features to encourage miscanthus adoption can reduce nitrate and phosphorus yields by roughly 12% and 10%, respectively, and biochemical oxygen demand (CBOD) by 22% and chlorophyll-a (CHLA) by 10%. Interestingly, scenarios that consider environmental policy components alone do not improve water quality as much as those that integrate biofuel and environmental features together. These simulations convert roughly 5% to 9% of existing land use in the watershed into miscanthus. Additionally, three theoretical scenarios that introduce higher conversion percentages (20%, 25%, and 30%) show enhanced water quality improvement. Through a coupled human-natural system (CHNS) lens, this case study underscores the potential of perennial grasses as a suitable BMP in the Midwest when encouraged by environmental and biofuel policies, and it also reveals a trade-off between nutrient reduction goals and land-use conversion.

Graduation Semester

2024-05

Type of Resource

Thesis

Copyright and License Information

Copyright 2024 Emma Golub

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