Connecting Sources, Solutes, and Metabolism to Characterize Urban Stream Biogeochemistry

Rivers integrate the hydrological and biogeochemical processes occurring across their contributing landscapes. As human activity reshapes both land surfaces and in-stream conditions, understanding water quality requires linking how water and solutes move through a watershed with what happens to them once they reach the river. In this talk we bring together two perspectives that span catchment-scale hydrology and in-stream biogeochemical processing, in systems ranging from mountain headwaters to urban and wastewater-impacted rivers.

The first talk will examine how hydrologic flow-path partitioning and watershed structure shape the export of carbon to streams, drawing on reactive transport modelling in mountain and snow-dominated catchments. This talk will discuss ongoing work extending these frameworks to urban catchments, where infrastructure can redistribute natural flow paths and alter the water quality signals delivered downstream.

The second talk will be focussed on the effluents of wastewater treatment plants (WWTP) as sources of solutes and organic particles along the fluvial network. The talk will examine the biogeochemical and metabolic responses of WWTP-receiving streams and will provide insights on controlling factors. The talk will end with a discussion of strategies to mitigate the WWTP inputs to streams. Particular emphasis will be placed to urban streams in the Mediterranean region, where water is scarce.

Bios

Dr. Devon Kerins is a Lecturer and Assistant Professor in the School of Civil Engineering at University College Dublin in Ireland and Principal Investigator with the UCD Dooge Centre for Water Resources Research. Prior to UCD, she received her PhD in Environmental Engineering and Biogeochemistry from the Pennsylvania State University and was a Voss Postdoctoral Fellow at Brown University. As a hydrologist and biogeochemist, she utilizes data-driven and reactive transport models to untangle how climate, watershed structure, and land use influence interactions between water flow and biogeochemical processes to drive carbon and nutrient cycling and, ultimately, water quality. Currently her research projects span mountainous, agricultural, and urban catchments in the US and Ireland.

Dr. Eugènia Martí is a stream ecologist and biogeochemist working at the Center for Advanced Studies of Blanes (CEAB, Blanes, Spain) as a Research Professor of the Spanish National Research Council (CSIC). Her research focuses on the dynamics and processing of organic matter and nutrients (N and P) in fluvial ecosystems and the environmental controls and biogeochemical mechanisms driving them. Her research has been conducted in Mediterranean streams draining both pristine and human-altered catchments. She is also one of the leaders of the Urban River Lab (www.urbanriverlab.com), an experimental platform aimed at assessing the effects of inputs from wastewater treatment plant effluents to urban streams and searching for Nature Based Solutions to mitigate them.