Development of a Socio-Hydrological Model for a Coastal Watershed: Using Stakeholders' Perceptions

Environmental and human systems are dynamic. Most hydrological models simulate a single response in watershed behavior from a particular change in the surrounding environment. Stakeholders play a key role in the dynamic nature of a watershed, and including their responses can help us comprehensively model watershed responses. In a coastal agricultural watershed, the non-linearity of the human-environmental system further increases due to the intense effects of climate change, making stakeholders' perceptions even more important. Agricultural productivity is being reduced in areas experiencing sea level rise (SLR) and saltwater intrusion. Agriculture is a major nutrient source to coastal waters worldwide, making farmers chief stakeholders. We anticipate farmers will change their land use land management (LULM) decisions in response to changes in policies developed to mitigate climate change issues. This study will develop a novel methodology to explore how farmers' perception of SLR,, ecosystem health and policy changes affect their LULM decisions and how these LULM decisions can affect nutrient concentration in a coastal agricultural region.

Our study will focus on the Tar-Pamlico River basin in eastern North Carolina (ENC). We will use interviews and surveys of at least 60 local farmers by random sampling to incorporate their perceptions into the model. The interview questions will be based on different policies (e.g. nutrient taxations and subsidies) under current and future climate change impacts, excess nutrients in the watershed and SLR. By integrating farmers' perceptions in Soil and Water Assessment Tool Plus (SWAT+), we will develop a socio-hydrological model. Farmers' interview data will help us understand their probable LULM strategies, such as changes in crop rotation, adding riparian buffers, or changes in nutrient application practices. We plan to forecast the watershed nutrient concentration changes through midcentury that result from farmers' probable LULM decisions by altering specific parameters and inputs to SWAT+. This unique methodology for developing a socio-hydrological model can help policymakers develop mitigation strategies for degrading ecosystem health in ENC and can be transferred to other coastal regions globally.