This study examined the influence of landscape features on stream nutrient concentrations within the Ichawaynochaway Creek watershed in southwestern Georgia. Baseflow concentrations of both dissolved (SRP, NO3, NH4) and total (TN, TP) nutrients were measured at 17 sampling sites monthly for a period of six months (July 2012 to January 2013). A long-term dataset (January 2008 to March 2012) was also analyzed for baseflow/stormflow comparisons of dissolved nutrient concentrations. Relationships among land-use, geology, soils, physiographic features and nutrients were analyzed at both the sub-watershed and riparian corridor scales. SRP concentrations were lower and NO3 concentrations higher than reported in previous studies of the region. Due to dry conditions during the sampling period, nutrient input was likely limited to groundwater contributions and land-use effects were minimal. Trends among water quality variables varied between the upper and lower portions of the watershed, suggesting differences in nutrient transport pathways due to spatial variation.

This study characterizes the mass transport of ions in two streams in the Great Smoky Mountains National Park, comparing transport between stormflow and baseflow periods. By comparing ion mass transport between these two hydrological conditions, the importance of soil and the governing biogeochemical processes will be underscored. Two water quality monitoring study sites were located on the Middle Prong of the Little Pigeon River and Ramsey Prong within the same basin. These remote sites were equipped with YSI 6920 multi-parameter sonde to record continuous 15-min data of pH, depth, conductivity, turbidity, and temperature. Additionally, ISCO 6712 composite samplers were used to collect stream samples during storm events. Baseflow was collected by grab samples prior to storm events, and stormflow collected by ISCO samplers. Throughfall samples were collected after storm events. All samples were analyzed for pH, ANC, and conductivity using an autotitrator. Inductively coupled plasma spectrometry and ion chromatography were used to determine major cations, trace metals, and anions (Ca2+, Na+, K+, Mg2+, Aln+, Cu, Fe, Mn, Si, Zn, SO42-, NO3-, Cl-, NH4+). Stage-discharge relationships were developed at each site utilizing a combination of field measurements and modeling. Velocity and area field measurements were taken to calculate discharges for mid- to low-flow stages while mid- to upper-flow stages were modeled using RIVER2D and verified with field measurements. Stage-discharge curves and sample ion concentrations were used to compute ion mass transport for a two year period in 2006 through 2008. Differences in mass transport of ions between baseflow and stormflow periods found that greater mass transport of ions, except protons, occurred during baseflow periods. These results indicate that on an annual basis ions are stored from input throughfall sources and released gradually through groundwater flow over time more than rapid interflow transport during storm events. This information illustrates the importance of soils and groundwater storage in the regulation of ion transport and streamwater quality in the Great Smoky Mountains National Park.