Episode 53: Sierra Snowpack
“I want people to pay close attention to what is happening to our mountain snowpack because this is the natural, free reservoir that provides anywhere from 3 to as much as 33 million acre-feet in a given year.”
A conversation with Dr. Safeeq Khan (UC Merced) about the Sierra Nevada Snowpack, snow-vegetation-fire interactions, and snow futures. Released May 19, 2023.
guests on the show
Safeeq Khan
Dr. Safeeq Khan is a Cooperative Extension Specialist in Water and Watershed Sciences at the University of California Division of Agriculture and Natural Resource. He is also an Adjunct Professor in Civil and Environmental Engineering at the University of California, Merced. Dr. Khan is the director of the Forest Ecohydrology & Watershed Systems (FEWS) Lab at UC Merced, which focuses on understanding watershed processes under changing environment and climate. He is leading cutting-edge research on developing alternative forest management and land use solutions for building water and watershed resilience.
Dr. Khan's research broadly focuses on understanding the interaction between climate and ecosystems to inform land and water management. He uses data-driven numerical models as a research tool to aid in the understanding of watershed systems and predicting hydrological change. He has led several projects, from investigating the impact of non-native tree species and groundwater overdraft on streamflow in Hawaii to mapping hydrological vulnerabilities to climate change in the Pacific Northwest. Dr. Khan is also a co-director of UC Merced’s first Innovations at the Nexus of Food, Energy and Water Systems (INFEWS) grant that focuses on connected wildland storage-cropland subsystems in California. Connect with Dr. Khan here.
TRANSCRIPT
Mallika Nocco
Welcome to Water Talk. In today's episode, we are talking with Dr. Safeeq Khan and assistant Cooperative Extension Specialist in water and watershed sciences with the University of California Division of Agriculture and Natural Resources, and an assistant adjunct professor in Civil and Environmental Engineering at UC Merced. He is the director of the Forest Ecohydrology and Water Systems Lab at UC Merced, which focuses on understanding watershed processes under a changing environment and climate. He is leading cutting edge research on developing alternative forest management and land use solutions for building water and watershed resilience.
So, Safeeq is a wonderful person for us to talk to right now because we've all got snowpack on our minds, or many of us have snowpack on our minds. And Safeeq really has a ton of expertise thinking about the Sierra snowpack, thinking about how best to manage it, and thinking about these interactions between snow and vegetation and water and fire. So, we're really excited to talk with him. And also, just do some Sierra snowpack 101 to get some general information about the Sierra snowpack. A lot of people have been talking about how rare, or unique, of a year this is for snowpack. But, , it's also nice to just have some intuition to understand what's happening right now. So, it's really great to talk to Safeeq.
And he's also just a wonderful colleague in UC Extension. We've all known Safeeq for a long time. He's kind of a leader in the water community across the UC system. He is one of the leaders of our water program team, which is our network of water scientists throughout California. So, he's really been a wonderful person to just know, within the UC system. And I think we all really enjoy talking with and working with Safeeq. So, Sam, Faith, what do you think about talking about snow and talking to Safeeq today?
Faith Kearns
Yeah, I think like you, Mallika, I'm always happy to talk to a good colleague, I do feel like Safeeq is definitely one of our most collegial and generous colleagues. And I am really grateful to him and Ellen Bruno for all the work that they do just coordinating water across UC Cooperative Extension. And it is obviously a great year to talk with Safeeq about the snowpack and the concerns that people have about lowland flooding over what really is probably going to be the next couple of months to even what sounds like a couple of years in terms of water in Tulare Lake. So, yeah, it's a great time to talk to Safeeq.
Sam Sandoval
Not only a leader on the specific title, but also a leader in terms of service, bringing people together, and being able to empower others. So, I think that that's something that Safeeq has helped us out. One other thing that is true: Water Talk will go from the headwaters to the ocean. Well, we've been talking about water and focus quite a lot on use or cities. Now we're going to the headwaters and understanding some of the processes.
I like also to have this podcast to be one of the 101’s. While everyone is talking about snowpack. In this case, it will be good to have a good refresher on a snowpack in the Sierra, the importance, and I think he also brings a long-term perspective from what used to happen to what is likely to happen due to climate change. So, I'm really looking forward to talking with him.
Mallika Nocco
Awesome. Yeah, I'm super interested. I'm curious, maybe Sam? Faith? One question that I had, and I guess we can also ask Safeeq, but a question that I was thinking what to talk to Safeeq about is of the snowpack in California, the Sierras are not the only place that their snow, but they seem to be the most significant component of California snowpack, but I was curious if either of you kind of had any sense of how it compared to other parts of California where there is also a snowpack. Is the Sierra snowpack like 90% of California snowpack?
Sam Sandoval
Yeah, definitely, we should talk with him. And I mean, there is some snowpack in the San Bernardino Mountains and the Tehachapis and so on. But yeah, the bulk of the snow is in the Sierras.
Faith Kearns
I mean, my sense is definitely that the what the snow that supplies water to the most people in California primarily comes from the Sierra, and so even though you do get fairly significant snow on, say Mount Shasta, that also will melt over the summer, it doesn't supply nearly as much drinking water to nearly as many people. And so, I think it's both the biggest source of fresh water from snowpack in California, and it provides water to the most people. So yeah, I definitely say it's important.
Mallika Nocco
For our listeners outside of California, because I've been noticing you. I've been noticing you listeners outside of California. You’re starting to grow. So, for those of you who are listening outside of California, one of the things that was kind of surprising to me was just starting to think about the snow as, Faith you were mentioning as, a reservoir in and of itself for water. And I just watched Sam give an extension talk a couple of days ago, and that was one of the things you said too Sam, just you talk about snow in a different way than I grew up thinking about snow.
Sam Sandoval
And I think we're going to also cross it another topic that might be of interest for what is coming: the fire season, and we're going to be talking about Sierra and fires. And it will also go through some of the cultural practices, Indigenous cultural practices that we are implementing, trying to implement again, and what have been the impacts of not doing it in the past. So, Safeeq definitely is crossing a lot of the different topics that we have discussed from a headwaters perspective.
Mallika Nocco
Absolutely. So, without further ado, let's talk with Safeeq.
Welcome to Water Talk, Safeeq, we're glad to have you here.
Safeeq Khan
Thanks for having me.
Mallika Nocco
Yeah, so you've had some really cool interests in montane, watersheds, forests, and snow hydrology. Can you tell us a little bit about what your path was like getting into this type of work?
Safeeq Khan
I kind of took a very unusual path. And this is simply because I grew up in a very rural part of India. I had no idea in terms of a research career, or, going abroad, to be honest with you. So, I was basically helping out my family with a lot of the farming activity day to day kind of, making sure that things are taken care of. My dad was a primary school teacher, so he was pretty much always out, and I was the only one at home.
So, I was kind of juggling between my own education and taking care of the family. Doing that, I think I had this natural kind of fascination towards nature. Just seeing plants, seeing soil, seeing water kind of flowing in the landscape and that part of India gets flooded quite frequently. So we saw that the flooding was kind of like an adventure. Every year, you wait for the flooding, to get out in the flood and just have fun. And so, I had that natural curiosity.
But I would admit that growing up in India, and many kids who grew up in India during my time in the 80s and 90s, we had no luxury of picking your career. We tried our best, and then we just grabbed the opportunity, whatever came our way. So, I basically got, after trying several years for the engineering, I finally got into the Ag Engineering Program, and then tried to make use of that and kind of align my interest what I was fascinated with, and then make that program actually fit.
So water came naturally to me. But I was mostly focused towards the on farm type of work. So, you probably don't know this, but my master's thesis was actually looking at earthworm activity in rice fields and how the dual porosity, or microporosity, that earthworms actually create impacts water and solute transport.
Mallika Nocco
Wow, that yeah, I wouldn't have guessed that. That's awesome.
Safeeq Khan
So that's the scale I was looking at. But then, I kind of felt like that was just too small of a scale. And I was more interested in something that was scalable, over which your science can be applicable to management. And then basically, during my grad school, I started looking at more watershed scale processes. So that was in Hawaii again, I landed in Hawaii.
Mallika Nocco
I know that's a piece of luck.
Safeeq Khan
That's a piece of luck. And, and basically, there is no snow in Hawaii, unless you go to the Mauna Kea and Mauna Loa, so the snow hydrology was not part of my training, other than just reading in the textbook. So, I really kind of started paying attention to snow and snow hydrology when I started my postdoc back in 2010, at Oregon State. So, that was my first exposure. So, I consider myself a newbie when it comes to snow hydrology. It's been only 14, 13 years.
Mallika Nocco
You've obviously done a lot in that time.
Safeeq Khan
If you're thrown in the water, you just learn how to swim, I guess.
Sam Sandoval
So the Sierra snowpack is a large component of all the work that you do related with watershed management in the headwaters. So, what better year to have Sierra snowpack hydrology 101 than this year? So, can you help us and help our audience to let us know how the snowpack works in California, and why and how this year is unique?
Safeeq Khan
Yeah, so the way I really look at the snowpack, and this is what really fascinates me, the snowpack is really nature's gift to us. And the reason I say that, because if you think globally, before we dive into California, there are about 8 billion people and over a billion people actually out of those 8 billion rely on snowpack for their freshwater supply. So, the snow, even though it's not always in front of our eyes, plays a big part in making sure that people have access to safe and clean drinking water for both, to use as well as for food and everything that we need water for.
Coming back to here in the US, in California and western US in general, I mean, about 60 million people actually rely on mountain snowpack for their freshwater supply. So, it plays a really big part in our day-to-day life, even though we don't really think about it. Just to give some more numbers to you. In California, we get about 100-million-acre feet of precipitation every year on average. And depending on whether you have a wet or dry year, anywhere between a quarter to half of that precipitation falls as snow.
So, there's a big variation from year to year. But that's quite significant. That's a lot of water that we get in the form of snowpack. And the reason I said early on that this is nature's gift to us, is because this is a natural storage. Because of this Mediterranean climate that we live in we don't really get precipitation or rainfall at the time when we need it the most.
So, imagine a life in California without snowpack. So, just the sheer magnitude of the snowpack water supply that we get, and we are blessed with the life imagining life without snow in California. It's hard to like even to comprehend. And I want people to actually really pay close attention in terms of what is happening to our snowpack. I feel like there's a lot of discussion on the groundwater depletion and drought and subsidence and everything that really comes with that, which is well justified.
But I think people really need to pay attention to what is happening to our mountain snowpack, because that is the natural reservoir that we really pay nothing to keep that reservoir running. But it provides I think anywhere, like if we just look at the Sierra snowpack, it varies from 3-million-acre feet in a really hot 2014 type of year, to as much as 33-million-acre feet of water in the snowpack, which is the same magnitude [as] I think our agricultural water uses about 30-35-million-acre feet a year. So, it's a lot of water we are talking about here.
Sam Sandoval
And Safeeq, I mean this year, so I typically go and download the snowpack on April 1st and then compare it throughout the different years. And for instance. I noticed 2011 was a wet year, 2017 was the wettest, but when you compare them head-to-head, actually the snowpack was less. And now in 2023, it is a larger footprint. So, why is this year unique? Or how can you tell us what is the difference between this year and other years in terms of snowpack?
Safeeq Khan
California is a very big state when you think in terms of latitude-wise. So even when you get on average the statewide let's say a year like 2011 and 2017. That doesn't mean that it's a good year for snowpack. Because if you think of the state's climate as you go towards the higher latitude from south to north, things get colder. Because you're gaining latitude. So, precipitation increases as you go from south to north, but you lose altitude.
So, Northern California, the elevation is much lower than, let's say, Southern, central, and southern Sierra. So, the amount of snowpack increases as you go from north to south. But precip increases as you go from south to north. So, and the reason I'm saying this, is because it really matters when it comes to the atmospheric rivers that hit California. So, it really depends not only from where they're originating in the Pacific, but also where they land where they have the landfall.
So, imagine, atmospheric river hitting close to the central and southern Sierra, where the elevation is pretty high. So, a lot of that precip, the moisture will get pushed by the mountains. So, you get a lot more of that person falling as snow. But if that atmospheric river moves northward and hits the Northern California coast, or Southern Oregon, then because of the lower altitude, a lot of that precipitation falls as rain.
So, you ask what is unique in terms of this year. If you think like all the atmospheric rivers that came this year, a lot of them actually hit, between November through March, a lot of them actually hit the Central Coast. So that was kind of a sweet spot when it comes to maximizing our snowpack storage. So, principle wise, I totally agree that this year is not too extreme, especially when you look at the Northern California and the northern Sierra. But the snowpack is pretty intense, simply because it just happened that a lot of the atmospheric rivers really hit the coast, which was really the sweet spot when it came to the snowpack accumulation.
Hopefully this gives you a larger perspective in terms of multiple factors and controls when it comes to the snowpack accumulation in the state.
Mallika Nocco
So, one question Safeeq, that's like not on the list was just a question that came up that we were wondering, is it with all of the snow that potentially falls in the Sierra, there's like snowpack in other parts of this state, and it seems like the Sierra snowpack is definitely the most significant snowpack in California. How does it compare? Is it like 90% of the whole snowpack that we get, when you think of Shasta, or you think of some of the other places in California where there is snow?
Safeeq Khan
Yeah, I would probably be close to 90%. If I have to just throw a number and this is basically my guess. And the reason I say that, because on average, I think just the Sierra alone, the peak snowpack is about 16-million-acre feet. And if you look at the statewide, on average, the total precip, that falls as snow is about 20-22 million-acre-feet. So, when it comes to really, the snowpack, it's all about the Sierra. Northern California does get some snowfall, depending on the year, but a lot of that snow doesn't really last very long, unless you are in Shasta, because most of that snow really falls and then it melts within a very short period of time.
Mallika Nocco
Are there any rules to be considered part of the snowpack in terms of when the snow falls, if it melts in a few days, "Oh, that's not the snowpack,"? You know what I mean?
Safeeq Khan
The snow falls, and then it melts, depending on what happens between the storms? And the question that people often ask, is it really the amount of precip that falls as no is relevant for water supply, or the amount of snow that you have accumulated over a long period of time, is really irrelevant. And it really depends whether you're talking about water supply for downstream users.
Then I would probably say it really doesn't matter what happens on an event-by-event basis, but really how much total you have accumulated over the entire season. Because by the time you start kind of preparing the farm and all types of the use cases, I think it's really the April, May, June, that's the melt season, that really dictates alright.
But the earlier melt, that's also relevant for the ecosystem. Imagine if you get really intense rainfall, a lot of the rain will not infiltrate into the soil, and it will probably runoff. But instead, if you get that precip as snow and if the snow sits there and even if it melts over a week, there's going to be a very slow melt. So, a lot of that water actually recharges the soil. It provides the water for the habitat. So, I wouldn't really say that this short-lived snow is not only relevant for us, it's relevant for the ecosystem.
Mallika Nocco
Okay, that makes a lot of sense. No, Thanks for clearing that up. These are just kind of getting all my snow questions out.
Safeeq Khan
These are very good questions. These are all nuanced questions.
Mallika Nocco
This brings us to this idea, because we have on Water Talk another Sierra episode we talked to Dr. Joan Dudney out at UC Santa Barbara, and we focused on the forests, and we just talked about forests and forest health. And we didn't actually talk too much about snow. But there is this connection.
So, I was wondering if you could tell us a little bit about the relationship between the snow hydrology, and then the forest vegetation that's in the Sierras?
Safeeq Khan
Yes. Thanks for bringing that up. And it just happened that one of my PhD students, just this morning, got his first paper accepted, looking at the relationship between the snow and the forest vegetation. Every time when we talk about snow, we talk about the downstream interest, we don't really talk about the role of snow in shaping or reshaping the mountain vegetation. So, it's really, really important, even if the snow is going to last there for a week.
Thinking broadly, I think the vegetation and snow have somewhat this love-hate relationship. And the reason I say this, because if you have a lot of snow on the ground, it's really good for the vegetation, because that's the water that is kind of stored there. Otherwise, the water would have gone off and not accessible by the tree. So, if the snow sits there, and melts during the peak growing season, the trees can actually tap into that resource and do what the trees are supposed to do. So, they really benefit otherwise, imagine in the peak summer with no rainfall how these trees are actually going to survive this four- or five-months long summer drought.
The snowpack is really a critical component of our forest ecosystem. Without the snowpack, I think you already kind of got the glimpse of what the future might look like during the drought when you had this massive tree mortality. And a lot of that was actually driven by the lack of snow on the ground. So yes, we had lower precipitation overall, but not having the snow actually amplifies the impact. Because whatever precip you got, the storage wasn't there, it's just runoff. So, the snow helps the forest basically grow and accumulate more biomass. But then what happens when you have this dense vegetation, that really lowers the snow accumulation. So, they're kind of fighting, I think nature is fighting in itself.
So, the snow, you may have heard that the snow does a lot of good things, other than providing water, it really suppresses the ground vegetation, it can actually thin the forest from the snow loading. So, it's really trying to create these patchy areas where the snow can actually accumulate. And then the trees basically provide the shading, and make sure that whatever snow that is on the ground stays long enough and kind of hidden in this microclimate. So, they're kind of protecting each other. But at the same time they're having this feedback between the snow and vegetation. It's a really nice nexus between these two processes that are feeding off of each other.
Sam Sandoval
Just use a follow up question. So, at the beginning, you mentioned that about 100 million acre-feet falls. And then between half or a quarter million drop as snow. So, what happened with the other half or three quarters? Is it just evaporated or taken by the forest and sent it back into the atmosphere?
Safeeq Khan
No, let me clarify that. So, what I was implying is that on average, here in California, we get about 100-million-acre feet of total precipitation. Out of that 100 million acre-feet, anywhere between 25 to 50 million acre-feet of that precip falls as snow. So, the rest will be rainfall. In terms of the total water that is available for runoff–it's anywhere between 40-to-45-million-acre feet. So, half of that total precip actually gets used by the vegetation. So that's basically your interception, transpiration and sublimation and all the other fluxes that return back to the atmosphere.
Faith Kearns
Safeeq, this leads nicely into the next question. It's still snowing in the Sierra, but, of course, people are already worried about fire season because we're always slightly worried about fire season at all times in California. So, can you talk a little bit just about what the snowpack might mean for fire season in California this year?
Safeeq Khan
Yeah, so the previous question was really kind of, feeding into this one. And as I was saying that the snow plays this dual role, where it's really, in a good year like this. If you go and hike in the Sierra this year, you will see way too many trees half broken from the snow loading. So, the snow basically does this thinning of the forest without us having to take the saw and machete and trying to clear the field. So, it's doing the work for us. So that's one thing.
The second thing is when you have snow sitting on the ground, and the ground fuel is literally covered so it's not accessible, and it's probably not ready to be burned. So, it really shortens the wildfire season, especially in a year like this, and then we are already in May, and we are just beginning or at least we started the melt season, but then got pushed into this cold front. So, we have yet to see the peak melt. And we are already in May.
So, if you have a good year in terms of the snowpack, it can really lower the window over which you get most of the wildfires. So, the snow cannot only lower the ladder fuel, it can also keep the ground fuel moisture wet for a longer period of time. And that really reduces both the likelihood of having a fire. But even if you get a fire, a lot of these microclimate, micro refugia, where you may still have snow or wet ground, that will really not let the fire get out of control.
So, the relationship between the snowpack and wildfire is well established. And this is really as a scientist, and as someone who really cares about our headwaters, imagining a future without snow in the Sierra is very frightening. Because if you don't have snow and our precip pretty much kind of stops in March. I mean, you get fewer storms here than there. But the peak of the wet season is from November to March. So, imagine a dry, hot summer, from April all the way to October. That's a very long summer hot window. And I can't really see how we can go and manually fight these wildfires without snow helping us.
Faith Kearns
Yeah, I mean, the only thing that I have been telling people is that's definitely the case in the Sierra. But , in sort of lower lying areas, particularly grasslands and Chaparral systems, we still need to worry about fire season, particularly as there's been so much precipitation and vegetation growth due to how much rain we've had.
I was just curious, when you brought up the issue of the downed trees, I was almost expecting you to then say that those would become more accessible fuel, but you're really talking about it from the perspective of thinning, essentially. And so, I'm just wondering, if when you think about that because the trees aren’t necessarily taken out at that point, they're just sitting there to essentially become fuel.
Safeeq Khan
Yeah, you're right, that they will eventually become ground fuel. But we don't have the same level of ladder fuel. I think the problem in the Sierra is really: if you get a fire and the fire burns on the ground, I'm not too concerned, as long as it's not threatening life and property. The problem is really these situations where the fire basically leaves the ground and then reaches the top of the canopy. And ladder fuels play a big part in that. So, we're not really fixing the whole wildfire problem, but at least the snow is helping us at least in one aspect of that wildfire puzzle.
And you're absolutely right, every time when we say that the snow and how the snow reduces the wildfire window. The years when you have a higher snowpack tend to be wetter years and with a lot of moisture coming in, we also do a lot of fuel buildup in non-snowy regions as you were saying. These foothills, Southern California coastlines and if you have a lot of these grasses and shrubs accumulating all that all that biomass so that's the other side of the story. So wet, wet season, good for water supply. Not so good if you happen to be in this lower mid elevation where you don't really have the protection from the snow when it comes to wildfire.
Mallika Nocco
That's really tricky. It's just so complex. I mean, it's hard. It's very mind bending to think about that. So, back to the frame of thinking of snowpack as being great for water supply. What are some of the strategies for enhancing snowpack for years that are not like 2023? And what resources might be needed to put these strategies into place?
Safeeq Khan
Yeah, so as I was explaining earlier you need enough opening in the forest where the snow can accumulate, but not as big of an opening where the snow is really exposed to the sun. Because in that situation, even if you get a lot of accumulation, that snow will melt, rather quickly. So, it's not really very useful for us when it comes to water supply for downstream users. So now, the question really is how can we create these patches where we can accumulate above average snowpack? And this seems to be tricky. There's been a lot of research on this on this topic into what's the right size of opening. And as you can imagine, there are way too many factors that really dictate that.
So, it not only depends on where you are relative to the equator, because the sun angle plays a big role, then, also how tall the trees are, because the solar radiation if you're sitting straight, then probably the tip, the height of the tree doesn't really play that much. But if it comes at an angle, then how much shade you're going to get on the snow depends on the length of the trees, and then you have the slope of the landscape, you have the aspect whether you are a north facing aspect, or south facing aspects. So, a lot of these factors that drive the water and energy budget really dictate what's the right size of opening, we should create. So, it's very nuanced.
And I think what we really need is basically landscape based prescription. We cannot really create something statewide that [says] this is how you go about doing it, because it's just so localized. So, the prescription needs to be localized, as well, otherwise, you may end up creating these large gaps that instead of doing good, they will end up actually harming the snowpack. I'm going to say this, and it's going to be controversial. A lot of the focus right now, when it comes to managing our forest for wildfire, is driven by really this fuel reduction. I think everybody's so much focused, that let's get the fuel out of the forest.
My fear is that if we take this wildfire view when it comes to managing forest and do not really pay attention, in terms of how is that going to change the hydrology, in particular, the snow hydrology, then we might create a different kind of problem both in terms of that you will not get the same level of protection, the wildfire protection that you're getting, when the snow is not lasting long enough. And plus, you're going to jeopardize the water supply for downstream users.
So, what I'm really arguing is that we really need to take a more holistic view of our headwater management. Yes, wildfire is on top of everyone's mind, and that's probably the biggest issue that we are facing. But how can we create a prescription that is looking at multiple aspects of the ecosystem, so it looks at the habitat, it looks at the fuel, it looks at the water supply, and not just the water quantity, but also water quality. Because if you open a big canopy, and you have a lot more snow accumulating, and then all of that snow melting in a really short window, then you might create water quality issues, because of the erosion and stuff.
So, how can you take a more holistic view when it comes to our headwater management? So, I don't know if we are really taking this view. So, that's why I said it's going to be pretty controversial because it's all driven by wildfire risk reduction.
Sam Sandoval
Other people that we have interviewed, Erica Gies and others, always talk about these systems perspectives rather than problem perspectives. And it is good to remember that we need to take a look at the system as a whole. Safeeq, you've been talking about fires, snow, forest, but we're missing our rivers. And so, could you tell us about headwater streams and why are they important?
Safeeq Khan
Yeah, so every time you hear the word headwater stream, I don't think there's a clear definition of what is considered a headwater stream. The way I look at it, anything above the dam, I consider that headwaters. Even though some of the rivers or the streams even above the rim dams, they're also dammed. But if you take a much broader view, I think every time when you say, headwater stream, I think in your head, you're thinking of first order or second order stream. These are small tributaries that's where the runoff begins, it starts accumulating and channelizing. So that's what we call the headwater stream.
And I'm glad that you asked this question because every time you think of a river or stream, that's not where your mind actually goes. You think of Sacramento River, you think of Mississippi River, or Colorado River. But if you add all the river length, 80 to 90% of the river length, or stream length, whatever you call it, those are the first and second order streams. So just the sheer amount of their footprint is pretty big compared to these big rivers that we often think of. And the reason I'm saying that is because of the ecological implication of that.
So, a lot of these small streams, they're really critical, especially in the western US where you have this Mediterranean climate. So, if you imagine if you don't have the base flow in these headwater streams, what would the species that really rely on those streams for their water needs. I mean, California is one of the most biodiverse states in the US, and many of those species rely on these small tributaries for their survival over this prolonged summer drought.
Sam Sandoval
And Safeeq, I'm really glad that you mentioned that. I mean, water is not created on the reservoirs. And the importance of protecting all the headwater rivers. I typically call them the water factories, when we have no one coming in there. So yeah, the habitat that they have there is good habitat.
Safeeq Khan
Yeah, I mean, I was just going to say that a lot of these small like the first, second order streams, they really sourced from snow melt. Because at that level, you don't really have a lot of base flow, it's really the snow, the late season snow melt, that it's trickling down and keeping those streams alive. And the reason I'm bringing this up, is because imagine a future where you don't have the snowpack, a lot of these streams will actually be dead and dry.
And just the ecological implication of a no snow future in these headwater streams is going to be a disaster. So again, I think we often get selfish when we say, the snow for water supply, but we mean water supply for us. But the ecosystem, even when both the streams are just trickling, their ecological implication is pretty big. So, again, another reason why we really need to protect our snowpack.
Mallika Nocco
I've never heard the term "no snow future", and it is a scary term. Is that a real concern? I mean, is a "no snow future" something that we should be thinking about? It's here, okay.
Safeeq Khan
It's already here. It's already here in this mid elevation, where the precip phase constantly shifts between rain and snow; a lot of those regions really don't see snow in most years. And a lot of the smaller streams were basically sourced by the snowmelt. And California is, in particular, very sensitive, when it comes to this mid elevation, what we described as the rain snow transition zone, because of this, just the steep topography. As we were discussing earlier, the northern part of California that is pretty low lying, lying, areas where the snow falls, and even just a half a one degree temperature warming will really kind of remove all of their snowpack.
So, it's already here. It's just because right now it's in this transitional snow zone, that we're probably not paying attention and that that elevation over which you get the seasonal snowpack is really moving upward and there's evidence of that. You see the global trend or even local trend, in the snow-covered areas, they're getting smaller and smaller. So, we're not talking about the next 50 years. The no snow future is already here. It's just a matter of finding where these places are.
Faith Kearns
So, Safeeq, you've already obviously touched a little bit on the effects of climate change directly on the snowpack. I'm wondering if you have any thoughts about just climate change in the Sierra, in general, how it'll affect watersheds and maybe headwater streams? Or just any thoughts you have about the changing climate in the Sierra?
Safeeq Khan
Yeah, so I think we talked about a lot in terms of the role of climate in shaping the future of snowpack. And it's pretty obvious what we have seen in the last 10-15 years the direction in which we are heading. And again, I don't want to dismiss the year like 2023, we will keep getting years like 2023. But in between, you will have this other type of years, the other extreme. And I don't think it's really good, either way because it's very difficult to manage extremes.
But the other side of the climate aspect, the vegetation, for example, if you do not have the snowpack, and if the vegetation has to solely rely on the soil moisture in the subsurface storage, in the Sierra, there's just not enough to keep the vegetation alive for that five, six months of summer drought. So, in a warmer climate, lot of the vegetation will actually die, and we are starting to see the signal of that. So that's just the vegetation itself.
And the implication of that dead trees basically means that some other type of species will take over. Like species that are more resilient to drought, and oftentimes they tend to be nonnative species, because the native species, the climate has passed beyond their climate range. So, that might bring more invasive species. And if we try to keep the same vegetation there, I don't think they can survive, given the competition with the other types of vegetation that are more equipped to drier and hotter climates.
And then also we talked about the wildfire. So, the wildfire playing into the vegetation water feedback, some people like to describe that double whammy. The drought is killing the tree, and then the wildfire is basically turning them into ashes. And then the other type of feedback when you get wildfire, the wildfire will reduce the snowpack even further. Because the white snow basically reflects the light. And as soon as you start getting these ash and char sitting on the snow, it changes the color, which changes the albedo, that really starts the melt process even faster. So, everything is connected to everything else, and that feedback is pretty fascinating.
So, I think when it comes to just thinking of headwaters, I think our climate future is pretty, I don't want to use the word depressing, but if anything we learned in these previous episodes of the drought, I feel like that is really the future we are headed to. If we don't take any proactive action, I think we still can make amends, and we can start to do things differently, and make sure that our ecosystem is better prepared to cope with the future in a warmer and drier climate. Otherwise, I think, this cycle of drought, tree mortality, wildfire, this feedback will just continue.
Mallika Nocco
While Safeeq, we always like to ask our guests if there's anything more that you want people to know about your work and how we can all support your efforts.
Safeeq Khan
Yeah, through this forum, I want people to pay attention to their surroundings and see what is happening and take ownership even if you really have no direct connection, so to speak, or no direct reliance when it comes to water or other types of natural resources. Because if not today, tomorrow, you will be impacted. So, pay attention what is happening in your headquarters.
See what land managers are doing and make sure that they're not focused based on their agency mission only. Make sure that they are looking at the system as a whole. So, if we are going to continue to manage our forest, make sure that we are not only mitigating wildfire risk, but we are also creating a future that is more resilient. A future that is more resilient for our water supply, a future that is more resilient for our ecosystem, species, and trees, and all types of life that thrive on those.
So, all I want is really to get involved and stay informed and be loud and vocal about something you do not like, register your opposition, and make sure that the people who are doing those things, they hear your concerns. Otherwise, I think if you don't look at these issues then, I think at some point, the same way that the wildfire suppression came in and now we are facing the consequences, something else will get created and then our kids and grandkids will face the consequences. So, just become an informed and active citizen of the state.
Mallika Nocco
Thank you so much for joining us today and giving us so much food for thought and I guess, food for melt.
Safeeq Khan
I like that food for melt. Yes.