Research Grant Recipients
Bhuwan Shah, Department of Agricultural and Biosystems Engineering
Mentor: Ryan Mcgehee, Department of Agricultural and Biosystems Engineering
Bio: Bhuwan Shah is a Ph.D. student in Agricultural and Biosystems Engineering at Iowa State University, specializing in high-resolution climate projections for environmental assessments. His research advances statistical downscaling and bias correction to enhance the temporal accuracy of climate models, supporting hydrology, agriculture, and infrastructure planning. He holds an M.S. from North Dakota State University, where he developed sensor-based drip irrigation systems for specialty crops. Beyond climate modeling, he explores water quality and watershed-scale assessments. Currently, with Water Resilience Collaborative support, Bhuwan investigates future climate impacts on runoff and soil erosion in Iowa, aiming to connect global climate projections with local water resource planning for sustainability and resilience.
Abstract: The HighResMIP activity within CMIP6 provides high-resolution (as fine as 18 km) climate data, offering a crucial opportunity to improve hydrologic modeling by addressing biases in coarser GCM projections. This project proposes to bias-correct (BC) and spatio-temporally downscale (DS) historical and future HighResMIP climate products using a novel stochastic method to be validated with Iowa Mesonet 15-minute and ASOS 1-minute weather observations. These subhourly input-tested as raw, BC, DS, and BC+DS forms, and paired with SSURGO soil and NLCD land use data will be used to drive a physical hydrologic model. This study will provide high resolution climate inputs for WEPP and validate them in Iowa’s Upper Duck Creek watershed, an agriculturally dominant region facing severe soil erosion and water quality challenges in its connected river network. By integrating bias-corrected and downscaled climate projections into hydrologic modeling, this research will establish a framework applicable to other watersheds and land-use settings globally, enhancing the representation of extreme events and improving climate impact assessments across diverse hydrological models. The findings will support adaptive water management strategies and inform conservation practices to mitigate climate-driven hydrologic risks. This research aims to strengthen the connection between global climate projections and local hydrologic impacts, demonstrating how climate data enhances water resource planning and adaptation strategies. The findings will directly support WRC’s mission to improve water security across the urban-rural continuum, guiding conservation practices that mitigate climate-driven risks.
Mia Waid, Department of Ecology, Evolution, and Organismal Biology
Mentor: Wenjuan Huang, Department of Ecology, Evolution, and Organismal Biology
Bio: Mia Waid successfully finished her B.S. in Environmental Science in 2024 at Iowa State University. Where she developed a strong interest in soil and water quality through her work with the Soil Biogeochemistry Laboratory at the EEOB department. Currently, she is pursuing a master's degree in Environmental Science, focusing on soil phosphorus cycling and water quality. Her graduate research is studying the performance of saturated riparian buffers, an edge-of-field practice, on reducing nutrient pollution in agricultural landscapes. By investigating phosphorus cycling in soil and water within the buffers, she hopes to encourage more effective conservation practices throughout the Midwest through her research.
Abstract: Saturated riparian buffers (SRBs) that intercept and redirect tile drainage water into the subsoil of a vegetated riparian buffer, are a relatively new edge-of-field conservation practice to mitigate water pollution from agricultural drainage. SRBs are proven to be effective in removing nitrate from tile outlets, but effectiveness of SRBs on phosphorus (P) retention remains unclear. We posit that a mechanistic understanding of the relationships between soil geochemical properties and P retention capacity can provide insights into potential co-benefits beyond nitrogen removal. Here we propose to leverage the ongoing research at two SRBs characterized by fluctuating saturation and conduct lab incubation to complement field observations of P loads to the surface water. We will collect soil samples (up to 100 cm depth) from two SRBs and incubate them under field capacity control and fluctuating saturation treatments to investigate how soil geochemical properties control soil P retention in environments with fluctuating soil water levels. We will test the hypothesis that soil P availability will vary as a function of soil geochemical properties in the SRBs as fluctuating water levels affects P binding to soil minerals and/or metals. We will (1) assess P transformations among different soil pools under fluctuating and static soil water conditions and (2) identify important geochemical predictors for soil P retention/release. This project will enable us to fill the knowledge gap about P dynamics at SRBs and offer opportunities to collaborate with professionals, develop mentorship skills, and participate in academic conferences.
Shoaib Ahmed, Department of Agricultural and Biosystems Engineering
Mentor: Michelle Soupir, Department of Agricultural and Biosystems Engineering
Bio: Shoaib Ahmed is a Ph.D. candidate in Agricultural and Biosystems Engineering at Iowa State University, with a background in Urban Engineering and a specialization in Water Resources. His research centers on hydrological modeling, watershed management, and spatial data analytics. With over a decade of experience in water conservation and modeling projects, he focuses on understanding environmental risks linked to antimicrobial resistance (AMR). Recognized as a “One Health” issue, AMR connects human, animal, and environmental health. Shoaib's current work models the fate and transport of antibiotics and AMR bacteria in agriculturally dominated watersheds.
Abstract: Antimicrobial resistance (AMR) occurs when bacteria become resistant to antibiotics, raising concerns for human, animal, and plant health. In the U.S., approximately 80% of antibiotics are used in animals, with 40-80% of ingested antibiotics still present in manure, contaminating agricultural fields and posing risks to water quality and public health. We have monitored the Black Hawk Lake (BHL) watershed in Iowa for AMR in stream water, identifying eight antibiotic-resistant genes (ARGs) through quantitative polymerase chain reaction (qPCR). However, the role of streambed sediments as reservoirs for ARGs remains underexplored. This research aims to quantify ARBs and ARGs in
streambed sediments for an improved understanding of AMR fate and transport dynamics in the BHL watershed. Sediment samples will be collected biweekly from two sub-watershed outlets (S11 and W12) between March and July 2025, with additional post-manure application sampling in the fall. Quantification of E. coli, Enterococci, and antibiotic-resistant Enterococci (tylosin- and tetracycline- resistant) will be performed using selective agar plating, while quantification of selected ARGs (tetT, tetM, tet33, strB, intI3, ermB, erm35) will be conducted using qPCR. Statistical analyses will be used to assess seasonal variations and relationships between bacterial and gene concentrations in sediment and streamflow. By integrating these findings with streamflow AMR data from BHL, this
research aims to provide a more comprehensive understanding of AMR transport and persistence in agricultural watersheds. The results will contribute to improved understanding and environmental monitoring of antibiotic resistance in freshwater systems.
Travel Grant Recipients
- Taylor Vroman, Performance Evaluation of a Dual-Chamber Pumped Woodchip Bioreactor: E. coli Removal, Denitrification, and Greenhouse Gas Emissions
- Emily Rehmann, Microcystins and biodegradation in Iowa lakes
- Karol Lopez, Transport of Antibiotic Resistance Genes in Aquatic Systems: Influence of Sediment Particle Size
- Logan Didier, Engineered living materials using biologically active hydrogel composites: Applications for environmental engineering
- Lillian Chang, Microbial Communities as a Pathway to Improved Woodchip and Corncob Bioreactor Design and Performance
- Alejandra Chavez, Fate of Wastewater Derived Antibiotic Resistance Genes in a Receiving Stream
- Wendy Yarborley Abbey, Regenerative agriculture to support soil health and water quality
- Jessica Rehmann, Application of a novel biofiltration media to remove taste and odor compounds from drinking water