Effects of Seasonal and Long-term Climate Variability on Nitrate Export in the Chesterville Branch Catchment of the Eastern Shore, MD
Abstract
During the past several decades, human activity increased the input of nitrogen (N) to aquatic ecosystems through land clearing, application of fertilizer, etc. In the Chesapeake Bay watershed, a large portion of nitrogen originates from the Eastern Shore with highly agricultural land use. According to some research, it is observed that time of nitrate arriving at the Chesapeake Bay would affect the amount of eutrophication. i.e. Earlier arrival of nitrate would worsen the eutrophication. And climate change could have a significant effect on both the amount and seasonal timing of NO3 in streamflow. The main objective of this research is to observe the seasonality of rainfall, temperature, hydrology and nitrate export in a well-studied watershed, and use a model to explore how the seasonal timing of rainfall, evapotranspiration, irrigation, fertilizer application and plant growth affect the seasonal timing of nitrate export, and how these seasonal timings might shift under climate change. Change of climate and application of fertilizer could alter several hydrological and N-Cycle processes, including lag time and transit time, streamflow and runoff generation, mineralization, and plant uptake, which are modeled by SWAT (Soil and Water Assessment Tool) in this research. Climate sensitivity analysis was performed first by running scenarios with extreme high and low changes in temperature and precipitation and fitting all seasonal signals into mathematical functions to get basic information. Through climate sensitivity analysis, we quantify the sensitivity of amount and timing for each response variable. Future projections of changes in soil moisture, temperature, and precipitation are derived from models archived as part of the Climate Model Intercomparison Project Phase 5 (CMIP5) project, and include the same collection of General Circulation Model (GCM) simulations used for the 5th Intergovernmental Panel on Climate Change (IPCC). After that, we simulate model response to possible climate, irrigation and application of fertilizer strategies by projected climate and irrigation scenarios. Based on our model assumptions and reasonable climate projections, we found there exists large uncertainty of seasonality in the future depends on climate scenarios. And other preliminary results will be displayed.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.H31F..05C
- Keywords:
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- 1807 Climate impacts;
- HYDROLOGYDE: 1834 Human impacts;
- HYDROLOGYDE: 1847 Modeling;
- HYDROLOGYDE: 1873 Uncertainty assessment;
- HYDROLOGY