Dr Tian Guo

Postdoctoral Research Associate
National Center for Water Quality Research

Heidelberg University

Dr Tian Guo is a Postdoctoral Research Associate from the National Center for Water Quality Research at Heidelberg University, Ohio, USA. She obtained her PhD degree from Department of Agricultural and Biological Engineering at Purdue University under the mentorship of Dr Bernard Engel. Her research focuses on evaluation of the impacts of climate and land use changes on crop yields, and sediment and nutrient reductions in the Great Lakes region. Her primary research goals are to address water resources and water quality issues. She has authored or coauthored 18 peer-reviewed papers and successfully obtained external funding. Her teaching experience and organizing Women in Engineering Program activities have required her to teach, assist and mentor students. Her professional experience included engagements with various stakeholders including government agencies, university researchers, industry partners, and nonprofit organizations, enabling her to build a network of diverse collaborators and solve complex environmental problems.

Multi-objective and multi-site calibration of APEX/NTT at the Edge of Field sites across the Western Lake Erie Basin

Field- and watershed-scale models are potential tools to evaluate management practices in reducing nutrients and sediment exports from agricultural lands. The Nutrient Tracking Tool (NTT) is a web-based frontend of the Agricultural Policy/Environment eXtender (APEX) field-scale model. The goal of this research was to identify a single parameter set of APEX/NTT to simulate annual crop yields, water balance, and nutrient loads across 19 fields in the Western Lake Erie Basin (WLEB), USA. A new tool for performing multi-objective and multi-site calibration of APEX in R was developed and was used to calibrate a common APEX/NTT parameter set for all the above sites. The calibrated APEX/NTT reasonably simulated annual crop yields, tile flow, surface runoff, dissolved reactive phosphorus (DRP) and nitrate-nitrogen (NO3-N) in tile flow, and DRP, particulate phosphorus (PP) and NO3-N in surface runoff. The results also showed that the tile drainage and phosphorus (P) transport subroutines in APEX/NTT need to be improved to realistically simulate flow and P through tiles. Nonetheless, the producers and stakeholders can use the resulting APEX/NTT model without calibration to evaluate the impacts of conservations practices on nutrient reductions and guide the implementation of agricultural conservation practices across the WLEB, to help alleviate P loading to Lake Erie. The research results can improve understanding of mechanism of the impacts of various conservation practices on crop yields and nutrient reductions at fields. Moreover, it can also benefit research on solving systematic water quality issues associated with both the old the new tile drainage systems.