WHERE ARE ALL THE DROUGHTS AND FLOODS COMING FROM? HAVE OUR WATER CYCLES FUNDAMENTALLY CHANGED? IF SO, WHY?
Ricardo Aguirre is an innovative civil engineer focused on flood control, seeks to change how we think about rainwater, desertification and how to leverage the genius of Nature.
HART HAGAN: My guest is Ricardo Aguirre. Ricardo is based in Arizona. He is 25 years into a civil engineering career with a focus on hydrology, storm water, flood control, and groundwater recharge. As part of that, he has trained himself in Holistic Land Management and is Executive Director of the Drylands Alliance for Addressing Water Needs.
Ricardo, how are you today?
RICARDO AGUIRRE: I’m fine, Hart. How are you?
HART HAGAN: I'm great, thanks. Ricardo, you live in the American West which is famously drying and desertifying. Do you have a solution to this problem?
RICARDO AGUIRRE: Well, I'd say Nature has a solution to this problem. We’re just leveraging Nature's intelligence and applying those practices and nature-based systems to demonstrate that the water issues in the southwest can be resolved.
HART HAGAN: People normally think of flooding and drought as two opposite things. Flooding is too much water, and drought is not enough water. But are flooding and drought related to each other?
RICARDO AGUIRRE: They're related to each other through the hydrologic cycle. As you indicated, I'm a civil engineer, and my focus is on drainage. One of the things that we study is the hydrologic cycle, which has dramatically changed, because land has changed. Much of the former world grasslands have become desertified.
As that has happened, it changes the hydrologic cycle. Under a functioning watershed the land tends to transpire as opposed to evaporate. Transpiration is a function of plants giving off water into the atmosphere. And when that occurs, you have a local microclimate.
When plants are removed and you've got bare soil--or rather desertification--then that local microclimate, that local hydrologic cycle, is not there anymore, and you get droughts.
But then when the rains come, they tend to come from oceans bringing in large clouds and large rain events that happen infrequently, but when rain does happen, it delivers quite a large volume of water. So it's definitely a change in the hydrologic cycle.
That's the short version of how the water cycles have changed.
But it's this change from a local hydrologic cycle to a more regional hydrologic cycle that changes this relationship between floods and droughts.