Development of a Multi-Scale, Multi-Model Geospatial Framework for Management of Diffuse Agricultural Pollution in the Conewago Creek in Southeastern Pennsylvania

Open Access
- Author:
- Aspegren, Laramie
- Graduate Program:
- Soil Science
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- June 25, 2021
- Committee Members:
- Bradley Cardinale, Program Head/Chair
Jonathan M Duncan, Thesis Advisor/Co-Advisor
Anthony Robert Buda, Committee Member
Douglas Alan Miller, Committee Member - Keywords:
- Chesapeake
Water Quality
GIS
Agriculture
Conewago
Nitrogen
Phosphorus - Abstract:
- Successful restoration of the Chesapeake Bay’s impaired water quality hinges on reducing agricultural nitrogen and phosphorus loads to the Bay. Managing diffuse agricultural pollution is spatially and temporally complex, and is the subject of a growing body of research in the Chesapeake. This thesis presents a multi-scale, multi-model framework for synthesizing a wide variety of data, models, and tools for understanding the spatial and temporal trends in nutrient pollution in Conewago Creek, a small agricultural watershed in southeastern Pennsylvania that drains to the Bay. Two Baywide water quality models, CAST and SPARROW, demonstrate a high degree of spatial inequality with regard to nutrient loads, that provides a basis for spatial prioritization and targeting. Within Conewago Creek, SPARROW model output, USGS gage data, and the preliminary results of a multi-season synoptic sampling campaign are combined to spatially prioritize portions of the subwatershed. One potential hotspot catchment in Conewago Creek is then used to demonstrate the fine-scale mapping of potential critical source areas at the field and flowpath scale. As a whole, the framework demonstrates an approach for synthesizing the wealth of water quality data in the Chesapeake Bay into an actionable understanding of water quality trends at finer scales, which can then be used to support local stakeholder engagement and restoration efforts. The document is presented in four chapters that move from the general to the specific. Chapter 1 presents a literature review and develops the overarching research questions that guide the thesis. Chapter 2 quickly demonstrates the basis for Baywide targeting and presents potential nutrient hotspots in the Chesapeake Bay watershed. The core of the document, Chapter 3, explores spatial and temporal trends in nutrient pollution within Conewago Creek using a wide variety of data and methods. Finally, Chapter 4 offers brief conclusion of the work as a whole.