Themes in our research

Urbanization

The global urban population is expected to double in the next 30 years. Our goal is to understand how these dramatic changes will impact water quality.

Social Vulnerability

The populations most susceptible to flood hazards are also the most vulnerable. Our goal is to understand how climate and land use change will shift social vulnerability into the future.

Landscape Modeling

Human alteration of the natural landscape changes the sources, pathways, and residence of contaminants. We model these interactions and identify solutions.

Aquatic Sensing

Many aquatic processes occur over short time-scales that are not observable using traditional data. We employ high-frequency sensors to identify cycling and transport of nutrients in rivers.

Ecohydraulics across scales

Reach Scale

We investigate small-scale processes, like turbulence, contaminant dispersion, nutrient
uptake, and toxin production. We use instruments that can sense the community composition of algal mats (fluorometers) and the micro-fluctuations of velocity induced by turbulence (acoustic doppler velocimeters).

River Scale

We investigate the impact of land use change on sediment and nutrient dynamics. We use instruments like high-frequency aquatic sensors to give us important information about water quality at sub-minute resolution. We also use physically-based numerical models to simulate connectivity.

Region Scale

We investigate the drivers of structural and dynamic connectivity of water and contaminants across landscapes. These drivers include climatic, tectonic, and anthropogenic forcings and require high-performance computing. We also use global datasets of hydrologic extremes and benefits.

Current projects

High-frequency sensing of water, sediment, nutrients, and algae in a rapidly urbanizing environment

Urbanization drastically alters water quality across space and time.

We use in situ aquatic sensors to understand the transport of contaminants at  novel timescales down to minutes and seconds. Our suite of sensor arrays includes measurement of turbidity, chlorophyll, nitrate, dissolved organic carbon, and other analytes. Our research findings highlight the impact of urbanization on increasing the connectivity of contaminants to stream corridors.

Key Readings

Husic et al. 2023 (Water Resources Research)

Gerlitz et al. 2023 (Journal of the American Water Resources Association)

Zarnaghsh and Husic, 2021 (Environmental Science & Technology)

Kelly et al., 2021 (JGR Biogeosciences)

Tracing land use controls on the sources, timing, and pathways of sediment transport

Sediment is the most common pollutant on the Earth’s surface.

We use sediment fingerprints (or tracers) to track the movement of sediment, from its erosion source to its depositional site. One such set of tracers are termed radionuclides, such as plutonium, which were introduced from nuclear weapons-testing fallout into the atmosphere. Another set of tracers are organic carbon and nitrogen, which encode the effects of vegetation and fertilizer on the fate of transported sediment.

Key Readings

Zarnaghsh and Husic, 2023 (Science of the Total Environment)

Percich et al., 2022 (Geophysical Research Letters)

Husic et al., 2021 (JGR Biogeosciences)

Modeling the connectivity of water and sediment, from hillslopes to streams, at local and continental scales

Hillslopes are dynamic features that link uplands to streams.

We assess how human, climatic, and land use influences modulate structural connectivity and infer how connectivity may impact the occurrence of hydrologic extremes and benefits, including floods, landslides, and wetlands. A better understanding of the drivers and consequences of connectivity can allow us to make informed decisions as anthropogenic forces shape climate and geomorphology into the future.

Key Readings

Michalek, Villarini, and Husic, 2023 (Nature Communications)

Mcvey et al.,, 2023 (Science of the Total Environment)

Husic and Michalek, 2022 (Geophysical Research Letters)

Michalek, Zarnaghsh, and Husic, 2021 (Science of the Total Environment)

Advancing knowledge and modeling of karst hydro-biogeochemistry

Karst systems transport groundwater at turbulent velocities.

Karst topography, which is characterized by caves, sinkholes, and springs, covers 12% of the earth’s land surface and provides drinking water to a quarter of the world’s population. However, the same characteristics that make karst unique also make it susceptible to contamination. We explore the pathways of transport in subsurface karst through machine learning and physically-based modeling as well as high-frequency aquatic sensing.

Key Readings

Husic, Al Aamery, and Fox 2022 (Journal of Hydrology X)

Al Aamery et al., 2021 (Journal of Hydrology)

Husic et al., 2020 (Water Research)