Document Type


Date of Award



College of Science, Engineering, and Technology (COSET)

Degree Name

Ph.D. in Environmental Toxicology

Committee Chairperson

Jason A Rosenzweig

Committee Co-Chairperson

Maruthi B Bhaskar

Committee Member 1

Shishir Shishodia

Committee Member 2

Yi Qi

Committee Member 3

Daniel Vrinceanu


Heavy metals, Remote Sensing, Socio-economic dynamics, Watersheds.


Intense urbanization and increased anthropogenic activity are two important factors contributing to the decline of soil and water quality in Houston watersheds, which poses a great environmental and human health risks. This study, therefore, was designed to: 1) determine nutrient and metal concentrations in soil and water samples along Carpenters Bayou (CaB), Cedar Bayou (CB), Sims Bayou (SB), Spring Creek Bayou (SC) and Vince Bayou (VB), 2) analyze land cover changes in watersheds using Landsat image analysis and 3) evaluate socio-economic characteristics and human health risks for each watershed. Soil and water samples were collected from three different locations with three replicates per location during the summer and winter seasons along each bayou. Samples were analyzed for a series of elemental concentrations using inductive coupled plasma mass spectrometer (ICP-MS) and total carbon and nitrogen (TCN) analyzer. Land cover changes and post-classification change detection for Landsat satellite imageries were performed using ERDAS Imagine v16.5 software. Spatial analysis and interpolation were conducted using ESRI ArcGIS-10.8 software. Analytical results showed that concentrations of Cd, Cr, Cu, Ni, Pb, Zn, P and N in water samples were in the range of 0.0–0.12, 0.0–2.80, 0.0–4.67, 0.0–2.62, 0.0–1.68, 0.0–44.35, 29.08–1829 and 539–4229 µg L–1, respectively, with concentrations decreasing as follows: CaB>VB>SB>SC>CB. Metal concentrations in soil samples for Cd, Cr, Cu, Ni, Pb, Zn, P and N were in the range of 0.20–1.02, 8.19–41.73, 3.33–35.57, 3.35–17.33, 3.56–31.66, 2.63–120, 48.94–883 and 323–3152 µg L–1, respectively, with concentrations decreasing in the following order CB>VB>SB>CaB>SC. Land cover change patterns were similar for all the bayou watersheds with high vegetative surfaces decreasing and low vegetative surfaces increasing significantly over the past three decades. All watersheds had increased population growth with population rates as follows SC>SB>CaB>CB>VB. Health risk assessments revealed risks for Cd, Cr, and Ni in soil via ingestion for children under age 6 as follows CB>VB>SB>CaB. This research is critical in improving our understanding on the impact of natural and human activities on Houston watersheds.



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