Greg Pasternack
Description: Greg Pasternack is a professor of Hydrology and Director of the Pasternack Lab at UC Davis. His research focuses on water management, looking at the impacts of human activities on watersheds and the best practices for river restoration. In this episode we discuss the role of hydrology, geomorphology, and ecohydraulics in studying and understanding the interactions between water and the environment. In addition, we touch upon the societal and individual decisions that impact the quality and availability of water, highlighting the critical issue of water usage in agriculture. Professor Pasternack shares the value of water sciences and encourages students to be better environmental stewards.
Websites:
Publications:
Application of a 2D Hydrodynamic Model
How to Strengthen Interdisciplinarity in Ecohydraulics
Book:
Show Notes:
[0:00:14] The Journey to Ecohydraulics: From DC to Davis
[0:04:40] Wesleyan's Professors and Conversation Culture
[0:06:24] Graduation Experience: Heartwarming and Meaningful
[0:09:15] Climbing a Volcano in Indonesia: Profound and Challenging Experience
[0:10:28] Exploring the Volcanic Craters of Kelimutu
[0:14:10] Defining a River Doctor and Their Mission
[0:18:55] The Tinkering Approach: Problem-Oriented and Multidisciplinary Thinking
[0:26:33] Limited Resources and Societal Behavior
[0:29:26] Tracking and Understanding Groundwater Levels
[0:32:39] Exploring the Use of Desalination Facilities
[0:35:37] Applicability of Principles Across Different Rivers
[0:40:21] The value of expertise and its application to real-world problems
[0:48:02] Climate change: A Symptom, Not the Illness
[0:48:54] The Global Sand Shortage and Ecological Collapse
[0:50:09] The United States' Neglect of Hydrology
[0:51:18] Investing in Physical Models for Understanding Rivers
[0:56:01] The Social Behavior of Organisms
[0:58:22] The Enigma of Career Choices: Water vs Bugs
[1:01:16] Individual Actions vs Societal Responsibility
Unedited AI Generated Transcript
The Journey to Ecohydraulics: From DC to Davis
Keller :
[0:15] So we'd love to start off by hearing a little bit more about your story.
How'd you get to Davis, and what got you interested in ecohydraulics? Thanks.
Greg :
[0:22] Yeah, you know, it's funny because I didn't end up where I thought I would, I would, or my high school friends thought I would, but I think I ended up where I was meant to be.
And so I'll explain that. So I grew up in the Washington DC area and during the Cold War, and I think a lot of us, oh, we'll just go work at the CIA or FBI or some of the industries aroundWashington DC.
I mean, today it's like, who thinks that they want to go work at the FBI, right? But I mean, that was like, when you're growing up in Washington, you're driving by Langley all the time andstuff.
But I also grew up right on the Potomac River, which is a gorgeous river.
And I grew up at a time when we really were just seeing benefits from the changes from the environmental movement.
And specifically, like the Potomac River previously had been somewhat industrialized from mining operations and its headwaters, and had been quite dirty, also just from the urbanization.
And it became quite clean. So by the time like in the mid 70s and early 80s, I was out kayaking on the river almost every day through my childhood.
And I had no idea that I was enjoying that benefit. So I grew up on a river.
[1:37] And when I got to college, I went to do a liberal arts education at Wesleyan University and I just took a variety of classes like elements of world musicianship, witchcraft in medievalEurope, and psychology.
And then I said, oh, let's just take an intro to geology class and see what that's all about.
And as that unfolded, it really resonated with my beliefs and upbringing and kind of led me into a path towards working on the environment and ultimately to a job here at Davis.
Brent:
[2:09] And then, did you value so much the liberal arts education from your, like, from your College days. Do you ever try to bring that into the classroom with your own classes?
Greg :
[2:17] I mean absolutely from day one as a professor here I have tried to replicate what I saw as the best practices at Wesleyan as a professor here at UC Davis I mean, I should say like Idid my master's at UC Berkeley and my PhD at Johns Hopkins So I I have experienced other kinds of university settings But I for the most part what I saw at Wesleyan was just you knowa lot better with how the teaching was being done.
Some of those things were really trying to instill critical thinking through the kinds of content that I curated and how I engage students with activities, trying to avoid multiple choicequestions for a long time.
Also UC Davis has some kind of honor code and expectations, but it's not the same culture as it was at Wesleyan.
So I tried to bring the values of like, Hey, I'm here as your shepherd.
Like I'm not here to just check the box and that you did this homework, you did that homework. Like let's learn together. I've curated all this material for you. Let's work through ittogether.
And over time, my teaching has gone more and more in that direction of like not a top down teaching environment, but more of like, here's what I've curated, you know?
And so you consume what you want to consume and learn. It's your education.
But still there is some amount of like the police part of like being a teacher that you kind of can't avoid either.
Brent:
[3:47] Certainly.
Greg :
[3:48] But I think the strength of the liberal arts education has always been and remains that it's just such great exercise for the brain to think about a diversity of big questions.
I have a cousin who's a history professor at Western Washington University coincidentally.
And you know, sometimes it's sort of jealous like, oh man, you get to talk about all the the big questions of history and ancient civilizations.
It's like, okay, well, what are some of the big questions that I could think about? Like if I was gonna try to inspire people with the environment, what would we wanna do?
And so trying to bring that into the classroom, I think that's what the liberal arts is about. It's like trying to get the underlying issues, not just trying to look at immediate technical, how do you calculate this or whatever.
Wesleyan's Professors and Conversation Culture
Keller :
[4:40] That's a very beautiful message and I'm curious to see, did you feel like when you were at Wesleyan that your relationship, your immediate relationship with professors was just innately more, I guess, like, willing to conversate.
Compared to at Davis where it seems like sometimes, like you said, it is like a policing force and students don't always feel as receptive to go up.
Greg :
[5:01] You know, I think that each department or major at Davis can have a very unique culture and some have a very strong community culture that I think is very powerful and effective.
And I mean, it's the same even at Wesleyan, there are some departments, of course, when you have a department that's of a certain size, It's just hard to instill the same kind of things thatthat that could could go on in a small major I was the major advisor here at Davis for the hydrology major, which is a very small major You know anywhere from 8 to 25 students at a timeand you know for that.
I mean we we could we could order catering from Alibaba You know and and have have like everybody get together and hang out and I mean just the camaraderie that can take placewhen you're in a smaller unit, if everybody, you know, shares that the cultural value of doing that is very powerful.
And I think at Wesleyan, all of the units that I was involved in were, you know, a small to medium size that where a real effort was made to do that.
I'll give you an example.
At graduation, okay, here it is, all of us. I mean, you know, Wesleyan has about, at the time, like 35 to 4,000 undergrads and about 1,000 masters or PhD students.
Graduation Experience: Heartwarming and Meaningful
[6:24] And there's a hill and then there's the football field and all the beautiful brownstone buildings.
And then there's the back side of the hill. So all of us graduating were on the back side of the hill.
As we came around to the front side of the hill, all lined up, there were two rows of professors and they were all clapping and we walk through as the professors around us clapped for usall the way through down to the stage.
Like that just was such a heartwarming and meaningful experience.
And I mean, it's hot in June in Connecticut. It's not quite as difficult as it can be here in the middle of June. I mean, you know, the sense of belonging and camaraderie and I think also, uh,Times have just changed in some ways, but you know the idea of like being invited over to a professor's house as a group and hanging out more more individual interaction was very umCommon and and in the in the you know in the 90s We were already doing a lot of first name basis for professor, which is now the norm So there there there was a closeness that's thereand I think there are professors here who try to bring those same values have that same passion so I you know I don't want to like Be particularly negative about Davis per se, but youknow if you've experienced or seen graduation, you know, it's a quite different experience here Yeah, my prep school commencement was the exact same thing.
Brent:
[7:52] I went to chote down the right down.
Keller :
[7:54] Yeah, I figured you would There's a certain level of connectedness like you were saying that it's very valuable at times And when we were preparing for the interview, we saw that inyour bio, in your time as an undergrad, you traveled a lot.
Could you tell us about your trip to Indonesia and kind of how that shaped your trajectory? Yeah.
Greg :
[8:13] Well, I mean, I think one of the other powerful things about a small school is that of all of the resources that exist there, because there isn't as much demand, then there's moreaccessibility.
And so, you know, professors use undergraduates to do a lot more or facilities that exist are more open and that just opened a lot of doors.
And so, one of the things that I had the opportunity to do is that a professor who is a geochemist was like, oh, Greg, you know, okay, would you like to do some research this summer?
Well, option one, we can stay here in Connecticut and you can go to the salt marshes and play in the mud and, you know, pick out some bugs and stuff like, okay, what's plan B?
Oh, we could go to Indonesia and climb a volcano and study the, what's inside the volcano.
Like what? So yeah, absolutely.
Keller :
[9:05] Okay.
Greg :
[9:06] We're off to the volcano, which was a profound and challenging and life altering experience.
Climbing a Volcano in Indonesia: Profound and Challenging Experience
[9:15] It's still to this day, like I'll have dreams about my experience on that volcano. And yeah.
The, uh, the, the volcano there is called Kelly Moutou. Um, it's on the island of Flores and, um, it's really a beautiful volcano, but just, it is incredibly challenging.
I mean, so basically, I mean, the professor was, was like, okay, Greg, like you figure this out.
You have like six months before we go, like figure out what are we doing?
You know, how do we do it? What are we going to do? And like, you know, I mean, obviously he was assisting me, we were working together, but it was like a huge burden, but also anexciting opportunity.
And everything you, you put on. Paper that you think, here's how it's going to go. Like none of that is going to work.
And then it's just about, okay, you know, what can I, what do I have in my chest here that I brought, you know, I carry a chest full of stuff, like, what do we have that is going to make thisall work?
You know? And so it was the professor, myself, there were two other undergrads who came to help And then there were two or three local scientists there from the Volcanology Institute.
Exploring the Volcanic Craters of Kelimutu
[10:28] And, you know, we had just this profound experience because it's a – the crater – there are three craters in the volcano.
And if you look up Kelimutu, like, on Google Earth, it's worth the time to take a look.
And the craters are, like, straight down. Like if imagine if you had an empty soup can and you're standing on the rim and you're looking down this hole It's like 200 meters or so orwhatever to the water surface At which time you have potentially boiling acid and then it's another you know I don't know 75 200 meters from there down to the bottom of the lake.
There's each lake is different And you know if you fall in you're dead one way or the other Not so pleasant Um, and so we had to figure out how are we going to get bottles down into thatwater, sample it at different depths and, and, you know, uh, and bring them back up.
And we had brought with us, um, a variety of tech now analogies to try to do that. Nothing really high tech.
[11:34] Um, because, you know, you're going to a faraway land with limited, uh, weight that you can carry and resources.
And, you know, we're not going, it's not like super high tech.
I mean, you know, we didn't have like the military supporting us or whatever.
We're just try to go and on the, on the fly, get some stuff. And so a lot of just.
Making making things up a lot of tinkering and it kind of just Let led to my thinking about science in a lot of ways is a tinkering process Which is true for any anything that's likeinvention related when you have to create something you just have to say well I'll try this or try that but it's just way more pressure when you've flown halfway around the world and And,you know, like half the people are sick and, you know, you're trying to like figure it out on the fly on a volcano.
So anyway, but it was a great experience. I think the biggest lesson I got out of that is just, you know, you try to prepare as much as you can.
You try to think of all the ways things can go wrong.
But you also bring enough materials that you can tinker on the fly and try to figure things out.
Brent:
[12:45] Definitely. from the professors who do a lot of field work that that is a very common theme that you can never truly fully prepare.
But you talk about tinkering and we want to talk to you about how do you tinker with rivers? How are you a river doctor?
Greg :
[13:02] Yeah so when I was in college and I was thinking about what I was gonna do after I graduate you know I was talking with a major professor and I said well I want to be a riverdoctor and this is the early 90s and he just said well There's no such thing that this sounds childish, you know, it doesn't, you know, like you have to say like I'm going to be a hydrologistor I'm going to be a, you know, you know, something ologist.
It has has to end in the ology or engineer or whatever.
And, uh, but that was always what was in my mind. The idea that, you know, uh, that why can't we just treat nature like a patient and then we try to diagnose his problems and come upwith solutions and, you know, um, that, that can help it.
And it just seemed to me that a medical kind of analogy is a little bit better than an engineering analogy, although it requires engineering tools at times, but not always.
There may be other solutions that don't involve engineering things.
[14:01] And so that's sort of always been in my mind. And it took a long time before I could stand up and say, I am a river doctor.
Defining a River Doctor and Their Mission
[14:10] But it, I think it kind of started to come back again when I had kids and, you know, daddy, what do you do?
And it's just, it's very easily understandable to somebody to say, yeah, I said, I'm a river doctor, you know, like that was something they could relate to.
Because my wife is also a professor in her own right. And she's a veterinarian, which, you know, you'd call an animal doctor. So we could just say, well, you know, mom is an animaldoctor and dad's a river doctor.
[14:41] So that's really, you know, I see like my life's mission is about figuring out what are the problems we have with individual rivers and what kind of actions could we take to healthem. And I see myself.
There, there may be other roles, like even with human health, you could be an epidemiologist looking at large scale patterns, you know, you could be a lawyer or politician or aneconomist like trying to work on health issues at a larger scale.
But somebody has to be there one river at a time, doing the hard work and mindfully figuring things out.
And that's where, where I feel like my role has been effective.
Keller :
[15:22] So what is a river? Yeah.
Greg :
[15:24] I mean, well, I mean, at the simplest form, a river is just the U shape on the surface of the earth that's been carved out by water.
You know, like water accumulating as rain runs off the land surface into a large enough amount that it can literally just, you know, push the dirt aside and make a U shaped channel andflow down there.
And then that get bigger and bigger as more water accumulates and you go down the hill.
So all rivers have in common that the force of gravity is driving something to carve them out.
And most of the time that's water, although sometimes it could be an earth flow of like landslide debris or something else. But generally, rivers carry water and materials from highlands tolowlands.
Brent:
[16:15] Yeah, and then could you define some of the general terms for us of hydrology, geomorphology, and ecohydraulics?
Greg :
[16:23] Well, it's so funny because like I was a first year student and I, after I took my first geology class, I went to the professor and I was like, okay, yeah, this is interesting. I like to takesomething else.
And I, and he, and I said, well, what's, what is there?
And he's like, looking at the course catalog and he's like, well, there's a course called geomorphology and I'm like, geomorpho whatto?
I mean, this is like, what kind of word is that? And what does that mean?
And, and yet, yeah. And, and so, but basically everything begins with the fact that the Earth's landscapes change.
You know, a lot of times we may not see them change, sometimes we do, and it can be quite shocking with landslides and floods, but the landscapes are changing, and so ageomorphologist tries to understand how it's changing, why is it changing, and what are the significance of those changes.
[17:13] And then, on Earth, water is one of the dominant mechanisms.
I mean, if you're in a desert, maybe it's wind. If you're in the far north or south, it's glaciers, but for most of the earth, water is one of, if not the most important ways in which the land getschanged.
And so, hydrology is the study of how water flows around, you know, where is it stored, where does it go?
And then, eco-hydraulics deals with the mechanisms of how biota is intertwined with all of these earth processes and water processes. home.
You know, life is, you know, water and life are quintessentially defining of Earth.
And so, yeah, so the, you know, that we can see on the Earth's surface, how things are changing, then organisms have adapted to that.
And so it's all that intertwining that's interesting to me.
Brent:
[18:06] Trevor Burrus And then would you say you are putting, you are in every one of those buckets? Dr.
Greg :
[18:11] Jonathan Sarna Well, that's, I think, yeah, that's, that's the thing that I think has changed over time that historically you would be an ecologist or, you know an engineer or ageologist or a lawyer and now there's a much greater understanding that if we don't look at something from different perspectives like multicultural perspectives or or the perspective ofwho is struggling with a problem, then we can't get to a solution because solutions usually are complex.
They're not simple. They're not obvious, you know? And so you have to be able to cross those traditional boundaries.
The Tinkering Approach: Problem-Oriented and Multidisciplinary Thinking
[18:55] And that's where the tinkering thing sort of comes into play because, and it's funny because a lot of who we are ends up coming back to our parents and our upbringing too.
You know, it's not like the training that I had, But, you know, when I was a kid, my dad was the kind of person who would try to just tinker with things like, oh, we have some littleproblem, I'll just make something, you know.
And it was never particularly pretty and elegant, but it worked.
And I think that is still applies here, it's just like, oh, well, what is the problem we're trying to solve? Or what is the thing that the river, what is its problem?
Now, if you tell me, oh, I've got to go learn about whatever the issue is, it's so it's a sociological issue or it's an engineering issue or it's a geological issue, whatever it is that we have topull in, uh, is that mindset of being problem oriented.
The risk of this approach is that you could become what some might call a dilettante is in other words, you could be like a pretender almost, you know, like, you know, you think, know,but you don't haven't really studied anything intensely enough to really understand how that works. Do you know physics?
Do you know chemistry? You can't know everything. No one is the avatar of everything, right? Yeah. You know, you can be a firebender or an earthbender, but you can't, only one personout there could be the avatar, right? It's not me.
[20:18] So, yeah, I mean, I think there's an extra burden to try to learn things deep enough to understand them.
But also, there are trade-offs there of finding the right balance of being a generalist and being a specialist that each person sort of has to work through.
I wouldn't say, like, I'm not the best at understanding the details of how fluids flow on Earth. You know, I'm not a computational fluid mechanicist at some fundamental level, you know,but I use those tools.
Or geology, or other aspects of engineering, or ecology, you know. Certainly.
Keller :
[20:52] So with that in mind, do a lot of these projects tend to be interdisciplinary when you're working with a given river or a given project?
Greg :
[20:59] Yeah. I mean, most of the time, the problems are, I mean, usually what people care about is how are things affecting some segment of society, you know, like the people part of it,and then some organism or some set of organisms.
Nobody's like, boy, that rock sure looks unhappy. You know, we better do something to protect the rock, right?
I mean, it's, you know, but if it's like there's some charismatic fish or the beavers, you know, or whatever, whatever the organisms are, bird.
And I, you know, I think it's valuable to focus on both humans and biota.
I think some people have also made the case that we do have to be mindful of the dirt and the rocks in their own right too, because for example, the world has a massive shortage of sand.
A huge problem for the future of civilization because we haven't taken care of that resource.
So, I mean, you know, you can overuse or ruin any anything, whether you could consider it a quote resource or it is more of like a living entity with rights of its own to care about.
Keller :
[22:10] And what are some examples of water management in everyday life?
Greg :
[22:15] Yeah, right. You know, it's so much of of what goes on inside.
We don't have to know about it. It just has to work, you know, and and water is one of those things.
Like for the most part, if we turn on our faucets, it works for whatever reason, people have been kind of conned into buying bottled water, myself included.
But, you know, we have a great water system, you know, you can pretty much just drink the water out of the faucet.
[22:40] But so much, there's so many things that society has made decisions that we as individuals aren't aware of about all kinds of things.
[22:48] And water is one of those things. So what is the quality of the water that we, that we drink or that we go and swim and recreate in?
Um, you know what, of course, having water available in the first place, um, when, if you have a house, where did, where is that water supply?
Who's paying for it? I mean, here in Davis, we went through a big debate, I think around 2015 about getting new water supplies that have been extraordinarily expensive because decisionswere taken by past generations to not participate in other water supply opportunities that could have been done at a much lower cost if they'd been taken.
So there's a lot of things behind the scenes.
And then of course, water at an international level, conflict between countries or states, you know, we see that in California, Nevada, Arizona, New Mexico, like, you know, fighting overwater, but then what about Mexico?
Like, do they get any water from whatever's coming from North America or, you know, and, and other countries as well. But on a day-to-day basis.
Most people, you know, if, if they're turning on their faucet and they expect, or they're buying bottled water, or they're trusting that that water is safe, it may or may not be.
But, but then it's the unexpected, it's the hurricane Katrina, or like this winter, we've had a, uh, in 2023, we've had a lot of flooding in, in California.
[24:12] And then we've had landslides, Um, a lot of homes have been ruined and, you know, it's, it's sort of when these disasters strike that, um, you know, reality is imposed on people andyou sort of just assumptions that were made that, you know, people don't say they don't want big government, but then the minute something goes wrong, they sort of expected thatgovernment wouldn't would be there for them, but you then only makes them want a smaller government, which then when something else goes wrong makes them unhappy even moreand it's sort of a cycle, you know.
Brent:
[24:46] And then with this winner as an example, are we kind of, through like the largest part of the snowmelt? Are we, haven't even seen it yet? Do you think there's gonna be moreflooding issues coming from the snowmelt particularly?
Or is that majority just caused by all the rain?
Greg :
[25:03] You know, I haven't kept up with where we are on the snowpack at this point, but, you know, for the, the last time I checked, cause I was interviewed for the news like a month agoor so, and as the snowmelt was getting underway in early May, and what I saw is that for the northern part state, there really isn't a concern of flooding.
There's still storage capacity in the reservoirs and even when they get full, to release from those reservoirs for most of them, there's not an issue.
It was really the Southern Sierras that had a really big snowpack and as well, a lot of flooding in the San Joaquin Valley that was already overwhelming the infrastructure that was there.
Um, I mean the, you know, the valley was largely a wetland historically.
It was meant to have water spread all over the place and that's really hard to stop. So there's, you know, uh, I've had people in the mountains send me videos.
The rivers are flowing clear, they're cold, but there aren't giant tree trunks coming down for the most part, you know, like big boulders washing around.
I mean, especially for the northern half of the state, It's a normal situation.
Brent:
[26:20] That's good to hear. And then overall, do you think we are managing our water correctly?
Maybe focusing a bit more on the rivers in cities or our tap water?
Like those two, I feel like are a bit more tangible for people.
Limited Resources and Societal Behavior
Greg :
[26:33] Yeah. Well, let's look at it. I always like to look at things from the perspective of civilization first.
And in general, I think individuals behave very similarly the way that societies behave or civilizations behave.
And that is that you don't worry about out a resource, if it isn't limited, you just use it. And you don't worry about it. You brush your teeth, you leave the water running. Why not? I mean,it's there, it costs so little, just whatever.
But when something becomes extremely scarce, then things really start to change and how you manage it.
If you're living on a desert Island all alone, suddenly a rubber band could be worth like a diamond.
So, you know, in California, from everything that I've seen, we have a tremendous amount of resilience to change if we so choose or if the citizens pass laws that demand that we makechanges.
And since the majority of the water is used for agriculture, it's not used in cities.
So, you know, I mean, you could use no water at all, yet a nearby golf course could be blasting its sprinklers all night long or an almond orchard that's a legacy orchard, maybe it's stillflooding its ground, it's flooding it rather than using drip irrigation.
[27:55] So there are still a lot of opportunities to conserve and change as the economics of of water change.
Keller :
[28:04] Do you know the stat off the top of your head of how much of our water goes for agriculture in California?
Greg :
[28:09] Well, I don't have it memorized, but I think it's around 70%, right?
Now one thing to keep in mind about water for agriculture is that there's the surface water like we store in dams and then we run through canals to get there.
But then there's also the groundwater that's being pumped out of the ground.
And the key difference is that the water that's in reservoirs is something we know.
It's like you see, you look in your cash register and it's what's there.
What's happening in the ground, most people aren't really aware of, but it's essentially, it's like mining.
It's like we're playing the game Minecraft and somebody's dug down there and you've dug out all the diamonds and coal, and there's just a bunch of rock left.
And so the problem is that when we take water out of the ground, on human time scales, it's almost irreversible.
I mean, you could pump some amount of water back down in there, but we've mined out, we have mined water out of the ground to produce almonds to send around the world.
[29:07] So most of that production is not serving us in California.
It's serving the world markets by a one-way transfer, by taking our valuable limited water resource and turning it into a food product that goes elsewhere, never to return.
So that's a very big difference between the surface water reservoirs and the groundwater reservoirs.
Tracking and Understanding Groundwater Levels
[29:26] And so a lot of the water we're using for municipalities coming from surface water reservoirs, although, um, for those, that's for the major municipalities, but still many peoplethroughout California are reliant on wells, because they're just, there are no pipes and infrastructure that's setting them clean water.
So they just are pumping whatever they can out of the ground too.
Brent:
[29:51] And then when we're thinking about groundwater, how well are we able to track its current levels? And then also if.
I don't really have much of an understanding. Do we, should we think about it as like a underwater lake that's there for across the whole state or how many of the different ways is itbroken up?
Greg :
[30:11] Yeah. Well, um, the way that I, you know, if I was going to try to make an analogy is that you have, imagine a stack of sponges.
So you just piled up a whole bunch of sponges in a stack like a sandwich and then each sponge is made out of a different material and it holds a different amount of water.
So it's, it's not like a, an open lake, like a journey to the center of the earth. And you, there's some dinosaurs down there, whatever in the water, it's like, you just have these layers of asandwich.
Some have more water, some have no water. And we don't often know where all those are.
I mean, it's, it's like an art form and an expertise to be able to like drill a test hole down and try to find, find water down there. And then the water has to be the right quality and the rightpressure.
So it's a little bit more complicated, but there, you know, I mean it was Transformative to the state of California and its economy when groundwater began to be used because in the 1800sThe state started off as a cattle based economy, you know, it's Spanish cattle cattle were so strong They could fight off wolves and bears, you know, they had a chance until the 1850s.
And so they were really hardy animals and they were harvested on these very large ranches and then ox pulled carts would bring the hides to the main ports in places like Monterey andSan Francisco.
[31:39] And massive number of hides were removed from the state in a three-way trade between Boston, Asia and California.
It's pretty interesting story with all that trade. But so.
But we were a dry land economy. They didn't know. They didn't know.
So there were some crops that people grew, but I mean, people from 1769 until 1870 or so were primarily a dry land economy reliant on the cattle.
Once we had the steam engine pumping up lots of water in California, which really came into effect in the late 1860s, 70s, 80s, increasing more and more, then now we changed over toirrigated agriculture.
And that fundamentally changed everything about how our state functions to this day.
Keller :
[32:29] Wow, that's fascinating. I had no idea. Yeah.
Exploring the Use of Desalination Facilities
Greg :
[32:39] Are there any cases in California or in the US where using desalination facilities is common?
It's best to start off by conserve where you can, reuse dirty water into other places that don't need that top level of water.
Like even at my house, the same water that comes to my house is used for irrigating my landscape as what we're drinking, but that isn't really necessary.
We could be using lower quality water for the irrigation if it was separate from the drinking water.
So I think there's a lot more that we could do, but there are certainly places where desalinization is an option. You just have to remember, what do you do with all the sludge that youproduce.
That's usually contaminated with all kinds of heavy metals or other contaminants so now you have a toxic waste you have to dispose of and in very large quantities.
Brent:
[33:56] And then we're thinking about rivers as a whole. What makes for a good healthy river?
Greg :
[34:02] Yeah. Well, you know, rivers have some general things in common, but they're, they're often quite different.
I mean, I think first thing is what's the chemistry of what's going on.
So, you know, the pollution level of how much stuff humans have put into that river, that's heavy metals, that's organic herbicides, pesticides.
[34:23] And so even caffeine, I mean, there was a study done in like Boston Harbor and Baltimore Harbor showing like massive amounts of caffeine in the water and chemicals from waymakeup and microplastics.
I mean, it's just this massive amount. So, first of all, like, is the water substantially clean to support a food web?
Web. Are there from small plants to like small animals to eat the small plants and then increasing size?
Do you have a food web that's alive and can survive given the chemistry of the water?
So those would be two parts of it. And then the part that's harder for people to appreciate is the physical side of it, that a river, almost like a person, it kind of has to be free.
You know, it needs to have free to receive water and have high flows and low flows.
It needs to be free to alter the channel and move around, make flood plains.
You know, a lot of the very productive farmlands we have are only productive because of thousands of years of rivers moving around, depositing nutrient-rich fine sediment, you know.
And so when you lock them in place and, you know, imprison them so that they can't do their normal functioning physically, then they won't provide what we need either.
Brent:
[35:36] Certainly.
Applicability of Principles Across Different Rivers
Keller :
[35:37] And how easy is it to transition? Like let's say you're studying a given river in California, are a lot of those principles, easily carried over across the world? Or are there differentdistinctions of rivers?
Greg :
[35:50] Well, yeah, it's a really important question. So some things, of course, are universal. Gravity, right? I mean, wherever you go, water flows downhill. I don't know.
Some people claim some places water flows uphill.
I don't know. But, you know, water flows downhill.
And so, you know, from areas of high pressure to low pressure, Um, there, you can make a fluid mechanics, weird things happen, but you know, because there are the general laws ofphysics, then those hold everywhere.
But still every river is peculiar because of the local conditions that are there.
Like the, the type of rock that's there or geological structures.
Like if you go to cash Creek here, so cash Creek is a, is a stream to the Northwest of Davis.
And if you go, it's in Cape A valley, and then you go up into that valley and you go up into the canyon, you'll see that there are ridges of rock running straight down the river vertically.
It's like take a sponge and turn it vertical and have that run right down the middle of the river. It's like really bizarre. But then as the river meanders, sometimes they're cutting across andthey create waterfalls and sometimes they're aligned with the river.
Like that kind of geological structural control of a river makes it unique and creates different opportunities and challenges for management.
So, I mean, there are general principles.
This winter, I was teaching a class for the first time formally as a class, ESM 125, River Conservation.
[37:20] And I started off with.
[37:23] You know looking at some laws and practices but as the class moved on i said you know let me do something very practical here and i just voluntarily took this class on a field tripif they wanted to go we went around we started in san francisco and worked our way north around the bay and we just went to rivers and i was like what do you see here let's just workthrough it and so like the same strategy you can start off with the same kinds of questions for all rivers and say yeah what where is the water coming from what is the sediment supplywhat do i see when i look at this river.
But you also just have to be open to the fact that A, humans have changed just about everything. So where are those human impacts on the system?
Don't assume what you're looking at is natural. And then B, what are the unique things here?
What are the assumptions about my training that I'm bringing to this?
As an example, some parts of the world, especially in the north but also in far south, southern America, are heavily glacier-dominated.
[38:22] And, uh, my very first postdoc was from Canada and ever he'd go here.
It was like, Oh, the glaciers did this. And the glacier was like, no, no, no, that wasn't a glacier thing here.
You know, like, so the lens of like what his training was in was driving his thinking and conversely, if I go to somewhere that's glacier and I haven't thought about it, I mightmisunderstand that entirely, or like I spent a sabbatical year in Australia and it has, you know, just these vast flat landscapes that are very different.
Like, so, yeah, so you have to be mindful to not bring your assumptions.
And it isn't that true in so many of things in life. Like, it's no different with rivers.
Brent:
[39:02] And is that what it means for your research to be like practical and problem-driven versus principle or like driven?
Greg :
[39:11] I mean, it is in the sense that we have to start, start with no assumptions when I go to a place. The first thing when I do, when I go to a river I haven't been to before, I have nothingto say. What do I know? I have to just start experiencing the river, get a feel for it.
Understand what the problems are at that place. First, what are people telling me? You know, are there indigenous people who have insights about what's going on there? Are there peoplewho've been living there for a long time?
What are they, what do they think?
And, um, start bringing those different narratives together, interpreting them, and then start bringing the science to bear on it.
So don't start by just saying, okay, yeah, I'm going to assume a trapezoidal channel and apply this formula and, you know, use that graph.
I mean, no, you know, it's like, let the story tell, let the river tell me what its story is. And then I've got to change my math or biology to fit its story, not the other way.
Keller :
[40:08] Could you talk about some of the science that you do bring to these problems when once you've had the chance to analyze and get feedback from the locals, like is that wheresoftware is like river builder come into play?
The value of expertise and its application to real-world problems
Greg :
[40:21] Yeah, well, so, you know, a lot of when you take a science and you bring it to real world problems, inevitably, there's an expert basis to things, you know, you're taking yourtraining.
And that's one of the values of going to college and going to grad school is like, you know, you're getting training, you become an expert.
And that has value and people value that. And that's what you essentially monetize in your career, right? And it was like, you are an expert in something.
So you're bringing that expert holistically.
But I've also always felt, you know, you get somebody where they've had their whole career, and maybe they're one of the best in the world at something.
And then eventually, they're going to pass on and that's lost.
[41:02] So I think that the quantitative approach in science and the software-based tools that apply quantitative methods.
The value there is trying to take expert capabilities and bring them down to people who have the critical thinking to understand, but don't have that technical expertise to have made alltheir own decisions.
And so much of what's happened in the last 20 years in our society is all about that from this very podcast. I mean, like, you know, none of us have to be, you know, sound engineers orvideo producers and engineers and cinematographers.
We're all producing video. All these technologies, that is, I think, one of the great advancements of the information age is taking very complex things, breaking them down quantitatively,producing tools that people can use. And so, that's what we try to do.
So, throughout my career, even on the volcanoes, we've tried to produce software that you can use to solve problems.
And so, for rivers, we do have a set of those tools.
Brent:
[42:09] And then, is your biggest goal being able to teach your master's students or undergraduates who are working for you how to think critically at a larger scale and then just apply thesedifferent tools when the problem suits it?
Greg :
[42:23] So, for the masters and PhD students, the first thing is I want them to create new tools. Like, I want them to identify a new problem that we haven't worked on yet, you know, couldbe, hey, we haven't worked on this vegetation or we haven't worked on beavers or turtles, like find something that we haven't applied our way of doing things to.
And then let's try that and make a tool for that. And especially, I mean, I think, I think especially it's really for me, it started more like 2008, 2009.
Before that, I was helping river managers on a river by river basis.
And we were making some tools, but it was still at a smaller scale.
But it really started to change as technology and remote sensing opened the opportunity to look at bigger scales.
[43:13] And then it's just sort of exploded since 2017 now where programming, most people in my lab group are doing coding as part of what they do.
And it's a challenge because across all of our experiences now, being able to code is becoming a fundamental language to be able to be productive.
It's not necessarily what we set out to do. Someone sets out to study rivers, but then they partly have to learn how to code as one of those things.
So anyway, but for your point, so masters and and PhD students, like their goal is to learn, you know, as becoming an expert, but creating a new tool that they're contributing, and thenthey move on, and then they're an expert of all the tools that we have.
Brent:
[43:59] And then are those tools public facing?
Greg :
[44:03] Yeah, so, you know, all of our stuff is free in the public domain, open source.
You know, I'm not an expert in computer management systems, but we generally, you know, just put it on the internet, either through my website or GitHub or other venues.
So anybody can use them. Now, the challenge is that throughout the sciences, like we're not alone.
Many, many people are producing many, many codes. We're all the scientists, not computer coders.
So there's a wide range of information about how do you use it and what if there's bugs in that stuff, right?
So when you have things that are academic and are not monetized, then it's hard to get the funding to put the level of detail to make it as good as like a commercial product that you couldfind off the shelf.
But there's a lot of tools that are out there.
Keller :
[44:54] That's good. Are there any commercial alternatives that exist?
Greg :
[44:58] For the things that we do, there aren't. No, no.
Keller :
[45:02] And then you briefly mentioned it earlier about the remote sensing, how that started to change the field. Could you describe what some of those changes are and kind of thedirection that it's heading?
Greg :
[45:11] Yeah, so the first five years of my career, I spent a lot of time outside on the rivers. I'd go out with my students and we'd be mapping a river and we you know we'd be...
We, we get, you know, you know, 50 to a hundred meters down the river.
We've mapped in great detail and it's like, oh my God, you know, like I've done like 50 meters.
How am I going to do 5,000 kilometers? Like, you know, right.
And so, but what has changed is now these new laser based tools.
So like, you know, you can fly in an airplane or be in a satellite and you can shoot a laser down to the ground, just like you're like a laser pointer, red or green or whatever color.
And, um, that laser will hit the ground, it will fleck back and it'll provide information about what's there.
And so this is, this is called LIDAR light detection and ranging.
Um, it's in a lot of products we have, you know, I think some of our phones or, you know, virtual reality sets, like they have these, they're using them.
They're just not necessarily making accessible to you. The connect was another example could do that.
Um, so these tools allow us to map in great detail, but still you just get this massive amount of data.
So how do you process it? So there's a lot of tools then that have to be developed to, to figure out how to, how to take advantage of that.
[46:35] The fundamental questions about rivers haven't changed, but what's changed is our ability to answer them in great detail and a great spatial scale that we couldn't ever do before.
Brent:
[46:45] And then when you're looking forward into the future of water management, what are some of the biggest issues you think maybe the U.S.
Is going to experience and have to tackle?
Greg :
[46:56] Yeah. I mean, I think like a lot of the problems are not technical.
They are, you know, societal, like, you know, we've talked about earlier.
I mean, still conservation, interstate issues.
But I still would bristle if anyone were to allege that water is a solved technical problem. It's not a solved technical problem.
We still can't accurately predict when it's going to rain more than 10 days in advance.
And even when they say it's going to start raining tomorrow at 5 o'clock and then it doesn't or it starts raining at midnight, it's still everything from the atmospheric science and the oceansand rivers, there's still a lot that needs to be figured out.
And investment in science is a real challenge. Investment in universities is a big challenge.
So overall, what I believe, based on my professional experience, is that the Earth is undergoing systemic ecological collapse.
Climate change: A Symptom, Not the Illness
[48:02] Climate change is just a symptom of this. It's not the defining problem of our times.
It's maybe the most important symptom, but it is not the illness.
The illness is that systemically humans have changed so many things on Earth at such scale everywhere that lots of things, all the large predators on earth have been removed. And whatare those consequences?
I mean, things as simple as like pigs used to eat seeds and then they would wander off and then they would poop the pit seed out and all the nutrients in the seed and it would grow a newtree. Like the whole structure of our forests have changed.
And water is part of that too, that the lack of availability of water from how we've used it is all taking place. place. The fragmentation of habitats around the earth, including in rivers.
The Global Sand Shortage and Ecological Collapse
[48:54] The fact that our earth is running out of sand and high quality soil.
Sand is a funny thing. You have all these deserts. You think, oh, how can we possibly run out of sand? But the problem is that deserts have rounded sand.
And when something is round, it just slips off. It just rolls away.
But when you go to to a beach on the coast, the sand there is not round, it's angular.
And so those bits of sand all interlock to each other. And that's the kind of sand that's needed to make cement. So we're almost, we're running out of sand around the earth.
And that why, you know, of course, where does sand come from?
It comes from the rivers, right? The rivers have eroded that material and carried them down to the coast. So it's, these are holistic problems where the whole earth is undergoing systemicecological collapse.
And so, if one accepts that or thinks that's a possibility, then some number of people have to be involved in trying to stop that.
And part of that is finding technical solutions, and part of that is working on societal solution.
Keller :
[49:57] Do you think part of that societal solution is going to come from new investment?
And along with that, in your career, have you seen an increase in investments in more climate-focused solutions?
The United States' Neglect of Hydrology
Greg :
[50:09] No, I mean, I mean in the United States, you know, it's it's been the opposite.
I mean, I feel like we're living in the era of scraps, you know, like the 1950s and 60s.
Well, coming out of World War Two, I mean, the lesson of what science could accomplish that facilitated victory in World War Two. who led to the growth of big science.
Why did we invest in oceanography?
We spend, I don't know the exact number, but last time I checked, it was like $280 million a year in the NSF budget on oceanography.
We spent a similar, about $280 million a year on atmospheric science.
Hydrology, or like the study of rivers. I mean, the hydrology budget at NSF is $10 million, the last time I checked.
I haven't checked it, but I mean, you know, it's an order of magnitude less than it is for oceanography. Why? Because oceanography and atmospheric science are part of the military-industrial complex, right?
Investing in Physical Models for Understanding Rivers
[51:18] I mean, so, it's, the 1950s and 60s, though, there was a huge investment in understanding rivers.
Here on this campus, we had a facility where they could rebuild rivers at a small scale. But you could say, hey, I want to build a dam or I want to build some facility in the state ofCalifornia.
And we had something called the Hydraulics Lab. It's still here, but it's not like it was then.
And, you know, and you could rebuild that thing as what we call a physical model, like, you know, almost like a sandbox, and then you could run experiments on it.
Today we rely on computer models more, but last week I was actually in Switzerland and I visited two facilities that, you know, make ours at Davis look like a joke. I mean, they're juststunning facilities funded by the Swiss Federal Institute.
One is right next to the University of Luzon and the other one is next to ETH Zurich.
I mean, they're remarkable facilities and in the U.S. There are only a few universities left that have those kinds of facilities.
One is like Utah State, Colorado State, to some extent. There's a few of them around, but there's been a dramatic de-investment in a lot of these problems.
[52:34] You know, the NSF's budget as a whole certainly is a sizable number, but Yeah, I think that a lot of us are just trying to fund what we can with very small amounts wherever we canget it Yeah, do you see a tangible benefit to those physical models versus the computer models when teaching people are experimenting?
[52:58] Yeah, it's a good question. I mean if you know Computer models are very powerful.
But of course, they only can simulate what you can program into it and And early in my career, I had an opportunity to go to University of Minnesota.
They're another one. They have a physical model facility right on the Mississippi River.
And I got funding where I could divert water from the Mississippi River through the building into this nine foot wide by six foot high, you know, like rectangular channel.
And I built the waterfalls in there and was doing research. It was pretty cool.
But you know, you could, when you're in a physical model and you're watching it, you You think?
Here's what I think is going to happen. Here's what I think and then it doesn't do that and it does something else and It's because the mechanisms of what the real world can do is very hardto put into a computer simulation We have to make assumptions and trade-offs for computational time costs like we just can't quite do it So the physical model is a really useful tool and itisn't necessarily that much more expensive Compared to the labor of you know when you have to make a complex computer model.
Brent:
[54:06] That's fascinating.
Greg :
[54:07] Yeah, another point about it is that most people, if you say, well, what's the purpose of science? The purpose of science is to find out why.
Why is this? Why is that? But the practice of science is really about why not?
It's about trying things that no one else in their right mind would bother to do. Why not? Let's just give it a try. And I have to give credit where credit's due.
I'm stealing this to some degree from a video game.
If anyone's played portal two, you know what I'm talking about.
Cave Johnson science is it's not about why it's about why not.
And I think that's a really important lesson because what we're supposed to do in science is try things that no one else will try, you know, usually there's some reason for it, but like whystudy waterfalls, but there's a tremendous amount that we can learn from waterfalls, but it doesn't even matter.
It's like, we should study things in nature simply because they're there.
Not just because they may have value to somebody down the line.
Often they will anyway, but there's a lot of things like we just have a part of the mission is just try to understand nature and how it works.
Keller :
[55:12] It's a beautiful message. With that in mind, what's been some of the most surprising discoveries or a particular discovery you've made in your career in the spirit of just trying tounderstand nature, something that you might not have necessarily gone in trying to learn about, but in your research, it kind of unfolded.
Greg :
[55:28] Right. Um, one thing that has been fortuitous, but also kind of surprising is that in some ways, organisms are really closely aligned to what the physical environment is doing.
You know, I mean, I, I do this, I do this, uh, experiment with, uh, one of my classes where I go over to the store and I buy a box of donuts, a big box of donuts, and I lay them out, uh,around the room And I asked them, go pick which donut you like, you know?
The Social Behavior of Organisms
[56:01] As as animals ourselves as humans like we're very social and you can look at other organisms and also identify that.
They have a lot of social behaviors to so there are things they might like or don't like or they may or are they just behaving innately there if they're following instinct in some way andthat's the point of the donut question is like trying to get at.
What is it that you really like and can an organism like something or not or is it just following its instinct.
But it's been remarkable the extent to which organisms align themselves with what nature provides for them to do.
And so we can surprisingly accurately predict where a fish is going to want to be in a river.
And that predictability opens up a lot of doors to be able to successfully manage rivers, which is surprising.
Because I've talked to a lot of people and they're like, well, fish might want to do this or might want to do that. But in the end, I just run the computer model. It tells me go look over thereand there they are. So I have been somewhat surprised that things can be predictable.
So some organisms are more specialists that probably are very predictable and some are more generalists that are harder to predict.
And humans are generalists, we're very hard to predict.
Brent:
[57:22] Have you been able to extrapolate some of the fish locations to mean, okay, that means the bears are gonna be over here, then that animal's gonna be over there. Have you been ableto expand it?
Greg :
[57:31] That's a good question. We haven't done that, and of course, that's because nobody's asked us to.
Brent:
[57:35] Fair.
Greg :
[57:38] Yeah, that would be interesting to see. And of course, that'd mean I'd also have to go put myself out where the bears are.
Brent:
[57:44] That's fun.
Keller :
[57:48] It seems like water sciences, despite the fact that we use them every day, Seemingly overlooked especially as undergraduates like I don't think I know anyone in the hydrologymajor here at Davis.
Brent:
[57:58] So there's only 30 Yeah, well there what not now there's like eight Wow.
I mean, yeah in a school 30,000. Yeah, right.
Keller :
[58:06] How do you write? How do you want to I guess? Very pretty is like how can we get students interested from a young age to where when they are in high school or when they're Inmiddle school water science is kind of like looked at as this field. That is more intriguing.
The Enigma of Career Choices: Water vs Bugs
Greg :
[58:22] It's been one of the enigmas of my career. I mean, when I was the master advisor for the hydrology major, I got it from like 8 when I started to 25 and then after I stopped it wentback down and now it's, you know, a decade later so it's about back at 8.
So, I mean, you know, it's a fundamental question.
Like, for example, the last time I checked, like two years ago, we have something like 35, 40 people majoring in bugs, entomology, right.
I mean, I'll tell you bugs and that's great. There's nothing wrong with bugs, but still like you have to do a reality check when you say, well, why we only have eight people on campusinterested specifically in water and, you know, bugs, uh, or, or anything else. And, um, I don't know. I mean, is it?
I mean, if you just say, well, water, water, I drink it.
I don't know. Right. I mean, there has to be something that inspires somebody to, to want to do something.
I mean, if you were to look at it from a financial perspective and you can say, well, gee, financially, oh, go be a doctor, go be a computer scientist.
But are those, are those going to work? I mean, already, like, you know, how many computer scientists have been fired, fired in the last year?
[59:42] But if you go into water, I mean, one of the points I make when, when the inevitably want to cancel the major, which is pretty much continuously for my career, it's to say, youknow, the world may not need us to produce a thousand new hydrologists every year, but the 10 we produce are going to have a really big impact compared to your thousand computerscientists or whatever else, you know?
And so it's that thing that there is, when you have a job or a career path where there is a shortage and is something that is technical, so it's hard to replace by AI or something, then itprobably is more resilient for a career into the future.
And so I think there is a practical message there that if you're looking economically, like what's a career that pays a good wage and will give me some better security into the future, thenwater is one of those that I think is resilient as much as anything looking ahead.
But from an inspirational point of view, usually it's somebody's, if I read an application, it's like, oh, I was rafting on the Colorado River and the sun beamed down on me just as mypaddle hit the water and I had an epiphany and I need to be a hydrologist.
[1:00:59] Things like that come to mind. Or for me, it's just, it was my way of life.
Like I grew up on the Potomac River. I was like a river rat, you know, like it just, it wasn't something that I, it was just part of who I was. And then when I made the connection that thatcould be a job, then that sort of resonated.
Individual Actions vs Societal Responsibility
Brent:
[1:01:16] And then as we wrap up here, do you have any parting words of advice or how to be better stewards of the environment?
Greg :
[1:01:24] Well, I you know on one hand people will say, you know You just have to look into your heart individually do do what you can do But at the same time I really feel like theburden is more at the societal level you know like society has to make decisions and pass laws and do things or Or what you do really, in my opinion, isn't going to make a whole lot ofdifference.
I mean, so, you know, you do what you think is right, but at the same time, we need to function as a society and a democracy to sort of get anywhere.
But I think like individually, the most important thing is just ask this question, why not?
Just try the things that others don't. That's really what I've done throughout my career is look for the contrarian thing.
What are the things that people aren't looking at and doing?
Was going out and studying waterfalls and the different things that I've done and yet in the end, when you can do something that few others can, then society will be the path to your doorand you will be valued and you will be able to support yourself and your family.
Brent:
[1:02:27] Wonderful.
Keller :
[1:02:29] Thank you, Professor. Sure.
Greg :
[1:02:30] Thank you.