Developing and Applying a Multi-scale Framework to Study the Relationship between Landscapes and Coastal Waters in the Texas Gulf Coast in a Changing Climate

This study seeks to improve our understanding of how upland landscapes and coastal waters, which are connected by watersheds, respond to changes in hydrological and biogeochemical cycles resulting from changes in climate, local weather patterns, and land use. This paper will report our progress in the following areas. (1) The Noah-MP land surface model is augmented to include the soil nitrogen leaching and plants fixation and uptake of nitrogen. (2) We have evaluated temperature, precipitation and runoff change (2039–2048 relative to 1989–1998) patterns in Texas under the A2 emission scenario using the North American Regional Climate Change Assessment Program (NARCCAP) product. (3) We have linked a GIS-based river routing model (RAPID) and a GIS-based nitrogen input dataset (TX-ANB). The modeling framework was conducted for total nitrogen (TN) load estimation in the San Antonio and Guadalupe basins. (4) Beginning in July 2011, the Colorado, Guadalupe, San Antonio, and Nueces rivers have been sampled on a monthly basis. Sampling continued until November 2013. We also have established an on-going citizen science sampling program. We have contacted the Lower Colorado River Authority and the Texas Stream Team at Texas State University to solicit participation in our program. (5) We have tested multiple scenarios of nutrient contribution to South Texas bays. We are modeling the behavior of these systems under stress due to climate change such as less overall freshwater inflow, increased inorganic nutrient loading, and more frequent large storms.