Estimating River Sediment Discharge in the Upper Mississippi River Using Landsat Imagery

Estimating River Sediment Discharge in the Upper Mississippi River Using Landsat Imagery
Author: Jonathan Acero Flores
Publisher:
Total Pages: 0
Release: 2020
Genre: River sediments
ISBN:

Excessive sediment transport adversely affects the hydrologic regime and water quality of a river and its drainage basin. With the decline of operational gauges monitoring sediments, establishing viable means of quantifying sediment transport is pressingly needed. In this study, I developed an alternative approach to address this issue where I applied the relationships between hydraulic geometry of river channels, river discharge, water-leaving surface reflectance (SR), and suspended sediment concentration (SSC) to quantify sediment discharge with the aid of spacebased observations. I investigated the approach with nine USGS gauging stations along the Upper Mississippi River — an important river system comprising almost half of the entire Mississippi River. I took advantage of the use of recent advances in remote sensing such as RivWidthCloud, Bayesian discharge inference coupled with at-many-stations hydraulic geometry (AMHG), and SSC-SR retrieval models. I examined 5,490 Landsat scenes to estimate the water discharge, SSC levels, and sediment discharge at nine locations along the Upper Mississippi River. Results showed that RivWidthCloud can be effectively used for Bayesian-AMHG discharge inference while the relationships between the SSC and Landsat SR are statistically significant at significance level [alpha] = 0.01 for all the study sites except in Clinton, IA. Acceptable gauge-specific SSC-SR model was obtained in the downstream having coefficients of determination R2 > 0.50. Similarly, acceptable regional-scale model was developed with R = 0.50. Further, results suggest that the three study sites at St. Louis, MO, Chester, IL, and Thebes, IL, in the downstream portion of the river, were the best locations for Q and SSC estimation with Landsat imagery. Estimations of Q were sensitive to the center of Q prior, which induces bias when inadequately estimated. Relatively, estimations of SSC were likely influenced by low reflectance of sediments during low flows due to chlorophyll and algae mixing in the water column. Lastly, I established in this study that combining the discharge and SSC retrieval from Landsat imagery can yield reasonable sediment discharge estimates having an average relative bias of 0.23, RRMSE of 0.95, and NSE of 0.40 for certain river segments in the Upper Mississippi River.

Sediment Response to Large-scale Environmental Change

Sediment Response to Large-scale Environmental Change
Author: Richard P. R. Pannell
Publisher:
Total Pages: 150
Release: 1999
Genre:
ISBN:

Knowledge about sediment yields is important in developing management strategies for fluvial systems. The effect of sediment must be considered in the design of river structures and in determining water quality for biotic systems. Changes in sediment transport regimes are difficult to understand or predict due to the complexity of factors that influence sediment flux in fluvial systems. Relationships about sediment source, sinks and transport have long been studied and many of these relationships have been quantitatively and qualitatively defined. However, due to the scarcity of long-term sediment records it is often difficult to test these relationships. This study examines one of these long-term suspended sediment records for the Mississippi River at East Dubuque, Illinois from 1943 to 1996. Daily suspended sediment concentrations from the United States Army Corps of Engineers station at East Dubuque were analyzed for the spring and summer months (March - August). Sediment concentrations were analyzed in terms of average concentration during different hydrologic events at the large basin scale. These events included the spring snowmelt runoff (low and high magnitude) and different intensity storm runoff (low, moderate and high). Additionally, peak sediment concentrations during storm runoff were also analyzed. The general trend for all of these analyses suggests a significant decrease in sediment concentrations from the 1940s to the 1990s. The strongest trends are found in high magnitude snowmelt runoff and in high and moderate magnitude storm runoff. Peak concentrations in storm runoff have decreased from about 1000 ppm in the l940s to about 200 ppm in the 1990s. Average concentrations have likewise decreased from about 200 ppm in the 1940s to 100 ppm in the 1990s. Changes in land management practices are identified as being the primary environmental factor influencing sediment concentrations.