We study how surface hydrologic processes interact with humans and climate. Our research focuses on two topics. The first is to quantify the relationships between climate, water, and food. The second is to understand the hydrologic processes that lead to floods in large river basins, including their connection to large-scale climate patterns.
CLIMATE, WATER AND FOOD NEXUS
Given the twin pressures of climate change and population growth, understanding the climate-water-food nexus is increasingly important to ensure water and food security in the coming decades. Irrigation plays a significant role in agricultural production, both through buffering against climate variability and allowing for crops to be grown in regions that would be too arid for rainfed agriculture. However, irrigation is the largest consumptive user of water, both within the US and globally. Climate impacts both the water and crop yields through climate variability, extremes, and change.
Our research focuses on characterizing the tradeoffs between crop yields and agricultural water use under varying climate conditions. We do this using historical observations and statistical models. One thread of research addressing this topic is how to model human activities in physically-based models to understand how human impacts propagate through the river network.
FLOOD PROCESSES AND SOCIETAL IMPACTS
Flooding is one of the costliest natural hazards facing the US and other countries. This is not a new area of research: some of the earliest hydrology problems were that of flood risk. However, with new, easily available datasets, we can quantify the physical processes that lead to floods across a variety of drainage basins sizes, from a small catchment to the Mississippi River. This research teases apart the relative role rainfall magnitude and duration, snowpack, and antecedent soil moisture play in determining whether a flood occurs. To do this, we have developed computationally efficient, high resolution modeling of flood flows.
Student-driven research is examining how the characteristics of floods – their magnitude, duration, and volume – impacts flood damages across the continental US.
HUMAN IMPACTS ON HYDROLOGIC PROCESSES
Humans affect hydrologic processes in a wide variety of ways. We extract surface and ground water for domestic, industrial, and agricultural use. We build small and large infrastructure, including dams and levees, that affect streamflow. We alter the land surface through changes in land use, creation of impervious surface, and stormwater structures. Our research is examining whether these alterations and activities change the hydrology, specifically the streamflow, in detectable, characteristic ways.