Water Resources

Drought impacts on terrestrial ecosystems have increased globally in the 21st century, and droughts are expected to become more frequent, extreme, and spatially extensive in the future. Historical site-based observations are inadequate to predict how future extreme water deficits will affect the global terrestrial surface, because future droughts and their impacts may be more extreme than they hav

Groundwater plays a critical role in the water balance, however the groundwater component of the hydrologic cycle is frequently overlooked at basin scales because it is difficult to observe and quantify. We address this problem through a novel framework that combines existing hydrological models and data sets with groundwater flux estimates across Earth's largest system of lakes; the Laurentian G

Fresh water is arguably the most valuable resource on the planet, but human activities threaten freshwater ecosystems. For example, use of synthetic chemicals, such as pesticides, road salts, and nutrients, has led to the ubiquitous contamination of aquatic systems, jeopardizing the integrity of ecological communities. Given the importance biodiversity plays in maintaining ecosystem health and fun

Water in the United States is used for myriad activities on a daily basis, such as for food (irrigation, aquaculture, livestock), energy (thermoelectric power or hydropower generation), and public water supply for domestic, commercial or industrial purposes. Yet, we lack an national accounting of how and where water is used on a temporal scale more frequent than every 5 years, and a spatial scale

Streamflow is declining in many parts of the United States (US) due to factors including groundwater pumping, land use change, and climate change. Streamflow depletion, a reduction in groundwater discharge to a stream due to human activities such as pumping and/or land use change, tends to evolve slowly and can be entirely invisible for many years to decades. This is because streamflow depletion c

River ecosystems support a wide diversity of biota, including thousands of fish species, which are variously adapted to the dynamic environments provided by flowing-water habitats. One of the primary ways that human activities diminish the biological capacity of rivers is by altering the natural hydrologic variability of river systems through regulation and diversion of streamflow for other uses.

Groundwater contaminated with naturally occurring arsenic is a widespread problem affecting many alluvial and deltaic aquifer systems throughout the world. The human health toll from consuming groundwater with high levels of arsenic is staggering in its proportions. Furthermore, the use of arsenic contaminated groundwater for irrigation is observed to result in diminished crop yields and thus pose

Models that predict the flow of rivers and streams are critically important for planning flood control, hydropower, and reservoir operations, as well as for management of fish and wildlife populations. As temperatures and precipitation regimes change globally, the need to improve and develop these models for a wider spatial coverage and higher spatial fidelity becomes more imperative. Currently, o

Global hydroclimatic conditions have been significantly altered, over the past century, by anthropogenic influences that arise from warming global climate and also from local/regional anthropogenic disturbances. There has been never been an effort that has systematically analyzed how the spatio-temporal variability of land-surface fluxes vary in natural and human-altered watersheds globally. This

Everyone needs clean drinking water in order to thrive. The US EPA and public water purveyors in the US work together in adherence with the Safe Drinking Water Act to make water safe for public consumption. The recent media coverage of lead in public drinking water supplies in Flint, Michigan, and schools in many cities with aging infrastructure throughout the US has raised public awareness of dri

Groundwater storage depletion is a critical issue for many of the major aquifers in the U.S., particularly during intense droughts. The GRACE (Gravity Recovery and Climate Experiment) satellites launched in 2002, with sensors designed to measure changes in the Earth’s gravitational field at large spatial scales (≥ ~200,000 km2). These changes are primarily driven by changes in water storage on the

Climate change is expected to cause more intense and frequent extreme weather events, but we only have a basic understanding of how these events might alter freshwater systems. Storms are likely to impact lake systems through delivery of sediments from watersheds and mixing of the water column, both of which could have important consequences for phytoplankton. Phytoplankton are the base of the foo