Weathering the storm
As an El Nino condition is gathering strength in the tropical Pacific Ocean this year, researchers from various schools around the UC Irvine campus are preparing to monitor its effects. Those may include high surf and tides at our region’s beaches and heavy precipitation that can cause landslides and flooding in inland areas. One of these investigators is Connor Broaddus, a Ph.D. candidate and soon-to-be postdoctoral scholar in the Department of Civil and Environmental Engineering. He’ll be out in the field to see how runoff-swollen rivers and creeks are transporting sediment to the coast, a natural mechanism for beach replenishment. Broaddus is our guest in this episode of the UC Irvine Podcast. It’s another installment of our special El Nino podcast series.
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“To Weather a Storm,” the music for this episode, was provided by Dan Lebowitz via the audio library in YouTube Studio.
TRANSCRIPT:
Brian Bell:
From the University of California Irvine, this is the UC Irvine Podcast. I’m Brian Bell.
This is another installment of our ongoing El Nino series here on the podcast. We’ve been reaching out to researchers across the UC Irvine campus in search of information about this large climate phenomenon. What causes it? Does it mean we’re going to have a lot more rain this winter? Will it result in flooding, landslides, and coastal erosion? How can Southern California residents protect themselves and their loved ones? We hope this series will provide our listeners with answers to these questions and much more.
This episode features Connor Broaddus, a PhD candidate and soon to be postdoctoral scholar in the Department of Civil and Environmental Engineering. He’s one of many UC Irvine researchers who will be out in the field this winter, along riverbanks, in flood-prone urban areas, and at Southland Beaches to measure El Nino impacts. The goal is to use these observations and data to better inform future responses to events like El Nino.
Our conversation with Connor Broaddus is up next.
Connor Broadus, welcome to the UC Irvine podcast. Why don’t you start by telling us a little bit about yourself?
Connor Broaddus:
Yeah. Hi, Brian. Thanks for having me. So I am currently a PhD student in the Efi Foufoula Lab here at UCI in the Civil and Environmental Engineering Department. I’ll be defending my dissertation in December and then starting as a postdoctoral scholar in the lab of Dr. Brett Sanders starting in January.
Bell:
So working with these distinguished professors here at UC Irvine, you’ve probably come in contact with some research related to weather impacts of El Nino on flood infrastructure, on coastal environments. Tell us a little bit about what you have seen and what you might expect to see from this year’s large El Nino event.
Broaddus:
Yeah, so it’s obviously El Nino is a hot topic of conversation in the popular media and among scientists right now. It’s expected to have some pretty significant impacts both inland and along our coastline. And maybe you know this, maybe you don’t. El Nino effectively warms up sea surface temperatures in the tropical Pacific. Those warmer temperatures can lead to increased storm activity along our coast. And those storms bring both heavy rains that can cause flooding, erosion, and they also bring large waves that can cause coastal erosion. And so there’s, there’s a lot of things that can happen with El Nino. They’re not necessarily guaranteed to happen, but we’re sort of taking this opportunity to study some of these impacts.
Bell:
We’ve already seen this year some heavy wave activity on the Southern California coastline impacting some areas. Dana Point, I think, got hit pretty hard so far this year. Has that been your observation that you’ve seen a lot of activity along the coastline this year?
Broaddus:
Yes. We’ve seen, we’ve seen some pretty large erosion events along the coastline. As you said, Dana Point got hit pretty hard. Laguna Beach maybe took some of the worst of it. Long Beach got hit pretty hard. And these, these large erosional events are based on some of the preliminary data we’ve seen are outside the range of observations that we’ve seen before. So there’s been a lot in the news about this being the strongest El Nino event on record and certainly some of the coastal erosion events that we’ve already seen so far in the late summer have definitely reflected that.
Bell:
I think a lot of people expect to see more winter rainfall as a result of El Nino, but what you’re saying is we’re already seeing impacts now and we haven’t even, we just entered fall.
Broaddus:
Yeah. So it’s, it’s tough to attribute any one event to, to El Nino specifically, but certainly some of the tropical cyclone impacts that we’ve seen from Hurricane Marie and, and other named Pacific storms so far this year have left the beaches in a state that they may be, maybe more vulnerable than usual to some of the impacts that could be coming this winter.
Bell:
You know, I went to high school in Florida and so Florida was a hurricane state. You would just normally see during the fall months these hurricanes and tropical storms come right up into the Florida and Gulf area. This year, there’s a really kind of weak hurricane activity in the Atlantic, but a lot of big storms in the Pacific. Do you think that might be related to El Nino?
Broaddus:
It’s possible. You would, you would have to speak to an atmospheric scientist to get a more definitive answer on that. But yeah, I would, I would agree that you, we typically don’t think of California as a hurricane-prone state, but we’ve definitely seen an abundance of these sort of tropical systems this summer so far. And they produce waves that come from a direction that we don’t see very often. And so those waves, because they’re coming from a direction that is not super common, can have sort of an outsized impact on our beaches.
Bell:
So we talked a bit about impacts on the coastline. Will there be impacts, do you think, in inland areas in Southern California
Connor Broaddus:
Yes, certainly if we, if we see some of the big rain events like we’ve seen in some previous El Nino years, then that can create, um, some flooding hazards. Oftentimes those flooding hazards end up coming with erosional hazards like landslides. And we’ve seen that in the past and, and it’s something that folks are definitely concerned about this winter.
Bell:
Are you, as a scientist, going to be keeping a, an extra sharp eye on these El Nino impacts this year?
Connor Broaddus:
Well, it’s, it’s funny that you ask, Brian. We recently in the, in the Sanders lab have been funded to study the possibility of moving sand along some of our river corridors to replenish the sediment along the coast. And we are taking this opportunity, this predicted wet winter, to study not only how water moves through these systems, but also how sand and other sediments move through these systems as well. So it’s definitely something that we’re keeping an eye on and, and sort of planning to take advantage of some of these storm systems to do some, some monitoring.
Bell:
How do you do the monitoring? You go out to a river, Santa Ana River or a San Gabriel River, or what have you with some kind of an instrument to, to gauge how deep the sediment is there or, how does that work?
Broaddus:
Yeah. Yeah, right on. We, we are focused right now on the Santa Ana River as well as San Juan Creek in, in sort of South Orange County. And yeah, the, what the monitoring looks like is essentially you go out there, we utilize bridges so that we have access to the full width of the river. You lower down a sampling device into the current while it’s obviously raining and storming outside, collect water samples, and then measure the amount of sediment in those water samples, the type of sediment, its size, um, things of that nature so that we can both, uh, understand how sediment is being transported through these systems, but then also be able to parameterize and calibrate models to represent how that sediment is moving through the river system.
Bell:
So, if El Nino produces a lot of precipitation this coming winter, does that not create an opportunity for us to do something with that water and exploit this resource in our very dry climate that we have here in California
Broaddus:
Yeah. Yeah, it absolutely does. There are already existing some locations along the Santa Ana River where OCWD, which is the Orange County Water District, does what is called infiltration. So they maintain a soft bottom channel that allows water to percolate down into the groundwater table and recharge our existing aquifers. But then also some of the considerations are how do we operate reservoirs in an efficient way so that we are able to retain as much of this flood water that comes down as possible for obviously use for drinking water and, and other sort of uses.
Bell:
Well, Connor brought us incoming post-doctoral scholar in the lab of Brett Sanders. Thank you very much for spending some time to talk with me
Broaddus:
Today. Yeah, absolutely. Thanks for having me on, Brian.
Bell:
You can read more about UC Irvine led research on climate change, El Nino, coastal conditions and flooding at news.uci.edu. While you’re there, please check out the other episodes of our special El Nino podcast series.
The UC Irvine Podcast is a production of strategic communications and public affairs at the University of California Irvine. Please subscribe wherever you get your podcasts. Thank you for listening.