Ethanol is playing a key role in current discussions on energy, agriculture, taxes and the environment. This work addresses the potential environmental impacts and behavior of subsurface fuel-ethanol releases. A continuous-flow 8,150-L pilot-aquifer tank packed with sand was used to simulate two spill scenarios: (1) fuel-grade ethanol (E95, 95% v/v ...

Recent studies have proposed the application of exposure-based criteria in developing alternative primary ambient ozone standards. Historically, epidemiological studies of ozone have approached exposure assessment in a simplistic fashion with simplistic methods used to estimate ambient ozone concentrations in exposure assessment. A new method for ...

This thesis presents a framework for a radar-based flood alert system (FAS) for the Oyster Creek Watershed to aid the City of Sugar Land in flood forecasting. The motivation for using this particular system stems from a radar's ability to provide flood warning lead-time when calibrated with available gauge information. This study follows a typical ...

Cypress Creek is an urbanizing watershed in the Gulf Coast region of Texas that contributes the largest inflow of urban runoff containing suspended solids to Lake Houston, the primary source of drinking water for the City of Houston. Historical water quality data was statistically analyzed to characterize the watershed and its pollutant sources. It ...

Flood Alert System (FAS2) incorporates adjusted real-time NEXRAD radar data, GIS, hydrologic models and the Internet to provide advanced warning to the Texas Medical Center (TMC) in Houston, Texas. It has been tested during 2006 season with excellent performance and was used as a platform to develop a real-time hydraulic prediction tool---the Floodplain ...

The behavior of a numerical solute transport model is examined under calibration conditions. Predicting ground water remediation using pumping wells is also examined. Model calculations are compared for calibration conditions and remedial conditions to determine the reliability of parameter estimates obtained from model calibration. Parameters ...

The design and performance of soil vapor extraction (SVE) systems can be evaluated using mathematical models. A lack of knowledge in how to select the appropriate model and use it properly for field settings are major obstacles limiting the usage of existing codes. The predictive capabilities of many of the commercially available models have never ...

This study evaluates a 1D and a 2D method for analyzing the combined effect of inland rainfall and hurricane-induced storm surge on a coastal floodplain. Horsepen Bayou near Clear Lake, southeast of Houston, Texas is vulnerable to storm surge, which can travel upstream into the Bayou and exacerbate flooding outside the designated floodplain. However, ...

Use of a standard three-dimensional flow model to simulate the saltwater interface in coastal and island aquifers as a no flow boundary is introduced. The method was used to simulate flow in a generic circular island aquifer. The results of this model compared favorably with those generated by an analytical solution and a numerical simulation. The ...

This study uses a distributed hydrologic model to assess the impact of wetland loss on flood peaks. There is large agreement among hydrologists that wetlands have significant flood-mitigation potential. However, the lack of data availability and the appropriate model have generally prevented this impact from being quantified and applied to city planning. ...