CAREER: Mitigation of Pollution Hazards in Ephemeral Streams and Estuaries; A Plan for Research and Education in Environmental Hydraulics

University Of California-Irvine, Irvine CA

Investigators

Abstract

9984579- Sanders This Faculty Early Career Development (CAREER) research and education project considers a promising approach for identifying key components affecting pollution hazards in surface water systems. A central challenge in developing strategies for hazard mitigation is identifying the key components that contribute disproportionately to outcomes. When these components are known in advance, engineering approaches for hazard mitigation can then readily follow. The approach utilizes an adjoint sensitivity formalism applied to a time-dependent and depth-integrated formulation describing flow and pollutant transport in streams and estuaries. The adjoint formulation yields a quantitative description of how system outcomes are related to system components and control actions -- information that can be used to determine the key components. This approach is particularly useful for examining pollution hazards in streams and estuaries, because the unsteady and nonlinear flow obfuscates the relationship between field observations, system characteristics, and source controls. The approach used is applicable to a wide range of pollution problems in streams and estuaries such as eutrophication, toxicity, and pathogen issues. It is particularly attractive in arid coastal regions in central and southern California, where the ephemeral hydrology presents challenges to the implementation of the TMDL (Total Maximum Daily Load) process set forth by the Clean Water Act. As a result, the TMDL process for a wide range of pollutants, including organics, metals, and pathogens, has not proceeded in a straight forward manner. This new methodology is used to identify the key components affecting microbial pollution in the Santa Ana River Watershed. It is expected that this will lead to insight into the equitable assignment of TMDLs for microbial pollution in a coastal watershed, as well as a better understanding of the true utility of the methodology, and strategies to manage pollution via control of the key components. With regard to education, the Problem-Based Learning method (PBL) is implemented in undergraduate and graduate courses in environmental hydraulics, that is, hydrology, hydraulics, and pollutant transport. PBL was first developed in the field of medicine, and results indicate that it better prepares students for life-long learning than the didactic method commonly used in engineering. A hybrid version of PBL that combines the PBL and didactic format is being tested, the goal being to foster critical thinking, self-direction, and self-motivation skills, while ensuring that the essentials of each course are covered. The objective is to prepare students for the Engineer-in-Training(EIT) exam--an important step towards professional practice. Watershed characterization and design problems from the field site are employed as the basis for PBL. Students are required to not only seek out and understand engineering methods of design and analysis, but to assess what site-specific data are necessary for analysis, and how these data can be obtained using rapidly evolving information technologies.