A spatial optimization approach to watershed water quality management: A case of the Opequon Watershed

Abstract

The Opequon Creek watershed is located in northern VA and the eastern panhandle of WV. Currently, the main creeks in the watershed do not meet VA or WV state water quality standards for recreational uses and aquatic life. In both states, the creeks are listed as impaired due to high levels of nutrients, bacteria, benthic and biologic impairment. The Opequon Creek is part of the upper Potomac River watershed, and ultimately impacts water quality in the Chesapeake Bay watershed. The main aim of this study was to develop a methodology that can be used to reduce nutrient loadings entering the bay area and improve water quality in Opequon watershed by implementing four innovative agricultural BMPs. The study develops an integrated approach to nutrient reduction incorporating three models involving water quality modeling, nutrient fate and transportation and an optimization model to recommend a least cost strategy for nutrient reduction. Special thanks to my advisory committee members Drs Gerard D'Souza, Tanya Borisova and Calvin Masilela for providing me with useful comments, suggestions, and the stimulating discussions we had. I would like to express my deepest thanks to Dr. Tanya Borisova for her invaluable comments on both theoretical and empirical areas of my research. I am thankful to Drs. Gerard D'Souza and Tanya Borisova for teaching Quantitative Methods and guidance in optimization techniques and model development. My acknowledgements to Professor Calvin O. Masilela, external member of my advisory committee, mentor and colleague, for his counsel, encouragement, undying support and help during all the stages of my Ph.D. study. Thank you so much in believing in me. Above all, this work would not have been possible without the undying support, sacrifice and encouragement of my wife Abigail. Thank you so much. I am also thankful to my son Anesu and my daughter Bethany for their patience and moral support throughout my study. My sincere gratitude is expressed towards Tom Basden for providing research funding through the Mid-Atlantic Water Program. Lastly, I am heavily indebted to all my friends during the Ph.D. program. Thank you for your help, support and encouragement. May God bless you all. CHAPTER 1: INTRODUCTION 1.0. INTRODUCTION Water provides the basis of life on Earth and the foundation of all civilizations. Increasing global demand for fresh water supplies coupled with limited availability of clean water and an uneven spatial plus temporal distribution of water supplies often leads social and economic problems. These problems include: struggles over access and use of limited water resources, lack of access to safe drinking water and inadequate sanitation, low economic growth and agricultural productivity, (Shah, 2007; UNDP, 2006; NRC, 2000). Thus, a major management challenge for water resources is maintaining water quality to meet human, plant and animal life (Cosgrove and Rijsberman, 2000). Increasing human populations and economic activities have continued to degrade existing water quality (Goolsby et a...

Application of a Spatially Explicit, Agent-Based Land Use Conversion Model to Assess Water Quality Outcomes under Buffer Policies

“…To illustrate the capability of APLUC to simulate alternative scenarios, three major policy scenarios were tested to project anticipated future residential land use development for the Opequon Creek watershed. These policies included: a baseline policy, which incorporated no additional regulation on residential land use conversions, a policy with 50 foot buffers along all streams in the Opequon Creek watershed, and a 50 foot buffer policy only within critical source areas sub-basins identified by Karigomba (2009). Two types of buffers are employed in the model: agricultural land use buffer and forest land use buffer.…”

“…A major concern of this residential growth is its impact on the Opequon watershed, which is already showing an increased level of phosphorus and nitrogen due to extensive farming (VT CTMDLWS, 2006;Karigomba, 2009). In terms of its location specific significance, Opequon…”

“…Identification of high priority sub-basins is based upon Karigomba (2009). For the policy scenarios in the model, developable areas, and non-developable areas are assumed to be designated by the local government as policy regimes.…”

“…In this study, the sub-basins are identified as high priority by both the Watershed Characterization and Modeling System (WCMS) nutrient levels and public participation prioritization method (Karigomba, 2009;Strager et al, 2010). WCMS, developed by the West Virginia University Natural Resources Analysis Center (NRAC), estimates the pollution concentration based upon hydrologically connected digital elevation model, which accounts for flow path and drainage area (NRAC, 2007;Karigomba, 2009). This approach helps in identifying the high priority sub-basins with consideration of hydrological pathways that influence the pollution responses.…”

“…Another effective method is a public participation prioritization method utilized by Karigomba (2009). In this prioritization approach, participation from the general public living in…”