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Simulating dynamic load of naturally occurring TOC from watershed into a river
1Department of Water Resources, St Johns River Water Management District, PO Box 1429, Palatka, FL 32178-1429, USA. youyang@sjrwmd.com
Water Research
|January 18, 2003
Summary
Rainfall significantly impacts total organic carbon (TOC) loads entering the St. Johns River from the Deep Creek watershed. Frequent rainfall increases TOC, with effects most pronounced in late summer, indicating a temperature-driven biological process.
Area of Science:
- Environmental Science
- Hydrology
- Water Quality Assessment
Background:
- Total organic carbon (TOC) is a critical indicator of stream water quality.
- Understanding TOC dynamics is essential for managing riverine ecosystems.
- The St. Johns River (LSJR) system's water quality is influenced by watershed inputs.
Purpose of the Study:
- To investigate the dynamic total organic carbon (TOC) load from the Deep Creek watershed into the Lower St. Johns River (LSJR).
- To assess the influence of rainfall events on TOC loading.
- To explore the role of temperature in TOC dynamics within the river system.
Main Methods:
- Modification of an existing watershed assessment model to incorporate TOC loading.
- Numerical simulations under daily, monthly, and annual scenarios.
- Integration of field measurements for model validation.
Main Results:
- Rainfall events were identified as a primary driver of TOC loads into the LSJR.
- Increased frequency of rainfall events correlated with higher TOC loads.
- The impact of rainfall on daily TOC changes was minimal in winter but significant in late summer.
Conclusions:
- TOC load into the LSJR is influenced by both rainfall patterns and temperature-driven biological processes.
- Seasonal variations in rainfall impact significantly affect TOC dynamics.
- The study highlights the complex interplay of hydrological and biological factors in riverine TOC transport.
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