Well, the slope of the Earth’s surface shapes areas that collect rainfall and direct it to a single point in a river. These areas can be as small as a football field and as large as covering half of the United States. We call them hydrologic catchments, and they are precisely what I want to talk to you about today. But before that, let’s talk about us, Humans. 

In our lifetimes, we experience a wide range of adversities: we get sick, we face emotional shocks and financial difficulties. Whenever we encounter those difficulties, it is always interesting to ask: why some of us are better than others at handling those difficulties? Why do some recover quite quickly while others don’t?

Now hydrologic catchments, as big and massive and different from humans as they are, they also experience adversities. These are in the form of floods, droughts, heatwaves, and wildfires. And recent studies showed that just like humans, the response of these systems to adversities can be quite distinct. Some catchments are vulnerable to droughts, some recover quite quickly, others a little bit slower while the rest might not recover at all. It is puzzling and unfortunately, we don’t fully understand the reasons behind this. Traditionally, environmental scientists have addressed this question by using expensive natural experiments or simplified model representations. 

However, these approaches have their limitations. So, here at Berkeley Lab, my team and I utilize recent advances in data science to address this question by learning from observations. In my research, I analyze a wide range of field measurements using algorithms of data science and machine learning to identify the key factors responsible for the behavior of these systems. By doing so, we are able to help decision-makers answer key questions such as: whether to build a dam? add a forest? or deforest a catchment area? How to optimally manage groundwater withdrawal during droughts? And so many other questions.

As the global climate continues to change, threatening our freshwater resources, these are the kind of questions we need to answer in order to make sure that hydrologic catchments always recover following disturbances to cope with future climate and provide us with fresh water for many, many generations to come.