2.2. Sediment Sampling Post Harvey
Six deposited soil samples (dried soil left after Hurricane Harvey due
to overland deposition) from the banks of Brays Bayou, and five
deposited soil samples from the banks of Buffalo Bayou were collected on
October 6 and October 9, 2017, respectively (Figure 1T). Brays Bayou is
the most urban bayou in Houston, whereas Buffalo Bayou is characterized
by its Addicks and Barkers flood control reservoirs that reached
capacity during Harvey and released water that exacerbated flooding and
significantly affected water quality in the Bayou (Kiaghadi and Rifai,
2019). Most of the stations where deposited soil samples were collected
were located in residential areas except station B6 (Figure 1T) that was
located in a commercial area. The deposited soil samples were only
tested for trace metals and not for Total Organic Carbon (TOC) and grain
size due to the dominance of white sand and silt. In addition, no
microbial analysis was conducted on deposited soil samples due to their
exposed nature to wildlife.
Bed sediment samples in the tidal segments of the HSC-GB estuarine
system (referred to as bed sediment samples for the remainder of the
paper) were collected from 11 sampling sites (see Figure 1B) during the
period from October 6 to October 27, 2017 (6-9 weeks after Hurricane
Harvey landfall). The number of samples was determined based on prior
knowledge of the HSC-GB while taking into account limitations in budget
and sampling logistics. Most of the bayous and streams were back to a
normal flow regime at the time of sampling with the exception of Buffalo
Bayou. In addition to lower flow rates from the discharging bayous,
satellite imagery (see Figure S1 in the SI) showed that sediment
transport had largely abated at the time of sampling. Thus, all sediment
samples were collected when the system had reached quasi-equilibrium in
terms of sediment transport and deposition. The details of bed sediment
and deposited sediment sampling and quality assurance are presented in
the SI.