Hurricane Harvey Essay

A sequence of SPM maps derived from VIIRS imagery using QAA-V revealed interesting patterns of SPM concentrations in Galveston Bay following Hurricane Harvey (Fig. 8 & 9). Hurricane Harvey, a category-4 hurricane, caused catastrophic flooding in the Houston metropolitan area and surrounding regions of Galveston’s Bay drainage basin with great potential to degrade the bay’s water quality. The dramatic increase in the discharge of water from the Trinity and San Jacinto Rivers into Galveston Bay (Fig. 9a) following the record rainfall and flooding associated with Hurricane Harvey reveals different patterns of discharge, with the San Jacinto River peaking and retreating to pre-hurricane levels much quicker than the Trinity River. This reflects

Although the Trinity Bay and the upper Galveston Bay responded similarly a few days following the hurricane, distinct SPM patterns emerged (e.g., lower SPM in the western and higher in the eastern part of the bay) just after two weeks suggesting different influences in the eastern and western parts of the bay. For example, flood waters from the Houston metropolitan and surrounding region appeared to have receded within a few days of the hurricane event (Fig. 9a), whereas the discharge of flood waters were elevated through the Trinity River over the course of several weeks after Hurricane Harvey. These flood waters could have accumulated first in wetlands and numerous water bodies in the eastern region and lower Trinity Basin during the hurricane event and eventually emptied to the main Trinity River channel. SPM was also elevated in the East Bay but concentrations were generally lower within the within the first two weeks suggesting this region of the bay mostly remained isolated from the other regions of Galveston Bay. Nonetheless, this region receives discharge from the surrounding wetlands which could have been elevated during this period. Overall, wind forcing was also important in controlling the extent and the dispersal of the sediment-rich plume waters into the shelf and in contributing to the SPM variability within the bay due to sediment

Despite the noticeable errors, especially in turbid regions of the bay, the application of QAA-V showed great potential revealing the SPM patterns due to post-hurricane variations in the freshwater inflow to the bay and in addition to wind forcing. The difference in field and satellite SPM matchups could be affected by several factors such as the errors associated with SPM measurements/techniques, atmospheric correction, and the assumption of linearity in the SPM-bbtnw532 relationship beyond the instrument threshold. A sequence of SPM maps after the passage of Hurricane Harvey showed that Galveston Bay received massive amounts of SPM due to large volumes of freshwater inputs from the major rivers and surrounding regions. However, while the freshwater inflow reduced within a few days in the western part of the bay, it remained high over the course of several weeks in the eastern part of the bay providing the evidence of the short-term storage capacity of wetlands and numerous freshwater reservoirs in the lower Trinity Basin. This discharge patterns coupled with differential residence times in the western and eastern parts of the bay resulted in distinct SPM patterns in the two regions of the bay. Furthermore, winds likely played in role in re-suspending sediments within the bay, but were critical in the transport and