Semester

Summer

Date of Graduation

2022

Document Type

Thesis

Degree Type

MS

College

Statler College of Engineering and Mineral Resources

Department

Civil and Environmental Engineering

Committee Chair

Omar I. Abdul-Aziz

Committee Co-Chair

Radhey Sharma

Committee Member

Radhey Sharma

Committee Member

Yoojung Yoon

Abstract

Stormwater runoff response in a complex coastal-urban basin varies with the changes in climatic and land cover drivers. This thesis aims to assess the runoff responses to variation in climatic and land cover variables and perform a sensitivity analysis in complex coastal-urban basins. The Buffalo San Jacinto Basin (BUSJ) of southeast Texas, USA was considered a pilot study area for this research. BUSJ is a heavily urbanized coastal basin, draining an area of 3132 km2 through the City of Houston, Texas into the northern Gulf of Mexico, USA. A process-based hydrological model was developed with fine spatio-temporal resolutions for the basin by using U.S. Environmental Protection Agency (EPA)’s Storm Water Management Model 5.1. The model was calibrated and validated with historically measured streamflow data from January 1 to December 31, 2020 (termed 2020). Rainfall and evapotranspiration were selected to represent the key climatic drivers, whereas surface imperviousness represented the major land cover drivers. These stormwater drivers were perturbed by -30 to +30% (with 5 percentage points increments) from their reference 2020 baseline values. The results indicated predominant and varying seasonal sensitivities of stormwater runoff to the changes in rainfall. Evapotranspiration changes led to consequential, but much fewer changes in the runoff than that of rainfall. However, runoff had stronger sensitivities to the changes in imperviousness, compared to that due to evapotranspiration in this heavily urbanized coastal basin. The quantified runoff sensitivities can provide important guidance for stormwater infrastructure management, improvement and development to achieve resilience and sustainability in the City of Houston and other areas along the northern Gulf of Mexico, USA and similar coastal-urban regions around the world.

Embargo Reason

Publication Pending

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