[00:00:00] Bridget Scanlon: I'm really delighted to welcome Kyle Davis to the podcast. Kyle is a professor at the Department of Geography and Spatial Sciences at the University of Delaware. He has numerous appointments at the university, which is extremely interesting, including an appointment at the Data Science Institute and also Water Science and Policy.
Kyle runs the Sustainability Lab, at the university and, what I was really impressed on the website, Kyle was, you indicate that it's science-based solutions for people and the planet, and I think oftentimes we're just focused on describing all the problems we have and everything.
So I really like that it's solution focused. So that's great. Kyle has received numerous awards, including U. S. Department of Agriculture, National Institute of Food and Agriculture, New Investigator Award. Science for Solutions Award. So solutions again, and Global Environmental Change Early Career Award. And the latter, both from American Geophysical Union.
So Kyle's research focuses on food systems and many aspects of food systems, including nutrition, sustainability, global environmental change, foreign land investments, human migration, and geospatial data science. So that's a lot of different things. So hopefully we'll just kind of get a smattering from the discussion today. Thank you so much Kyle for joining me today.
[00:01:36] Kyle Davis: Hey, great to be here. Thanks for the invitation and really looking forward to the conversation.
[00:01:41] Bridget Scanlon: Right. So,we, we interacted recently when we were putting together a proposal, with Lorenzo Rosa and, but I had been aware of your work for many years and, really admire what you're doing. So one of the things,Kyle, is, in some of your recent papers, you mentioned, the huge population growth globally 10 billion by 2050, and then also in addition to population growth, income changes and improving income that could lead to, changes in diet and maybe increasing meat consumption.
And so all of this then, putting pressure on food production. so one of the approaches would be to intensify agricultural production, using irrigation. And the recent paper, that you coauthored with Mehta and others in 24, you describe what has been happening with irrigation over the past 15 years since 2000. So we'd love to hear what your thoughts were from that analysis and, and what do you think it means for food production?
[00:02:45] Kyle Davis: Yeah, sure. yeah, so that paper, I guess it was intended to meet both an information need in that there's kind of these increasingly outdated global gridded data products on irrigation. And so that was kind of a fundamental information need that we wanted to fill in the water science community.
So we developed a time series of global gridded maps showing the evolution of the area equipped for irrigation from year 2000 up to 2015. And so we think that that's going to be really useful for global crop modeling community, for the climate research community, for the water science community, for being able to look at changes through time but also we wanted to see more of the science based question related to that was, the extent to which expansion of irrigation and decisions about increasing irrigation infrastructure are made being conscious of the availability or sustainability of water resources in different places.
So, the, the other part of that analysis that we did was to look at, okay, where are there places where there's current blue water scarcity? So, where ground and surface water resources are being, demanded and consumed at a faster rate than they're being replenished. And we wanted to see, okay, In those places where there's a state of blue water scarcity, to what extent has there been irrigation expansion and we found that it really kind of is an even mix of outcomes where it's about half of the irrigation expansion that's happened globally since the year 2000 has been in places where water is relatively abundant, but then the other half of that irrigation expansion has been in places where conditions of water scarcity and water stress already existed. so all of that, the long and short of that is really that the much of the efforts at sustainable and integrated water resource management that have been undertaken between 2000 and 2015, we don't see clear evidence of those have or are having an observable effect, consistently. Since the start of the century. So that's a quick overview of what what we found for that
[00:05:17] Bridget Scanlon: Right. And,we've been quoting the maps from the year 2000 and we have to acknowledge we're now 2024. So that's a bit dated. So I'm delighted that you updated those maps. And I mean, area equipped for irrigation, maybe you could describe a little bit about how you developed those maps and how it may be different from what Stefan Siebert maybe had done previously.
[00:05:44] Kyle Davis: We worked closely with Stefan Siebert. He and Matti Kummu and several other co-authors are on the paper. So I see it as kind of like a natural extension of the work that they that they that they began and undertook and helping to continue to build out those processes. Yeah, one of the goals with, the work that we're doing is to try and make everything more community focused in terms of the water research community.
So making all of the code to develop those types of maps open access, making all of the subnational irrigation statistics that we gathered freely available in open access and making all of the data outputs, freely available in open access. So that's, it's meant to kind of prevent this, the case where these maps, I mean, there's, it's substantial effort to be able to build these maps, it takes a year or two of just simple data gathering.
Going through agricultural ministry reports, combing through FAO STAT and AQUA STAT and a variety of different data sources just to gather and compile all of that information. so that's part of the reason why those products become outdated is because it's such a heavy lift, but our idea is, okay, we want to help extend those things, but we don't want to be the only group to extend those things.
And so, the, the area equipped for irrigation maps that we've developed and we, we've just, worked with Stefan Siebert and his group to also update the MIRCA crop specific irrigated and rain fed harvested areas up to 2015. all of that is out there for the community. So that's, that's, that's kind of the goal of all of those efforts is to be able to provide that information basis more regularly and in a more updated way
[00:07:29] Bridget Scanlon: Right. And, and I always quote Stefan's work from 2010 where he says, global water use irrigation accounts for 70 percent of global water withdrawal and 90 percent of consumption. So it truly is the elephant in the room in terms of blue water and blue water for the listeners is like surface water or ground water and green water is rainwater that goes into the ground that the crops can use and access through the soils.
So, 50%, about half of the irrigation expansion then over the past, from 2000 to 2015 was in areas that were water stressed and of course there are a lot of factors impact where you irrigate. I mean, where you have been irrigating where there's plenty of sunshine in many regions, in semi arid regions, where we grow a lot of our food.
[00:08:16] Kyle Davis: Even in the U. S., the Central Valley,we tout it as a great thing, but really should be growing most of our vegetables in the desert, or. Yeah. And I think the important thing to point out about that study is it's really only focusing on 1 aspect of sustainability water sustainability, and there's lots of other considerations that come into play when farmers and governments and investors are deciding on where they want to implement irrigation.
So, the types of crops, obviously, that can be grown in a place based on the soil and climate characteristics, how deep the groundwater table is. If it's going to be a groundwater based irrigation system, how far away the river is, all of the farmer income considerations and livelihoods considerations, value chain considerations and food security considerations.
There's all type, a whole host of aspects of sustainability that really come into play. And our study suggests basically that water sustainability isn't necessarily the primary consideration in a lot of contexts when you're thinking about these. The benefits of agriculture, increasing agricultural productivity,
[00:09:25] Bridget Scanlon: Right. And so you're mapping the area equipped for irrigation. And sometimes when I look at these irrigation circles, people look in Google Earth or whatever, they can see these big circles and, and oftentimes they're irrigation circles and see the high plains or Texas or Kansas and places like that.
But oftentimes now, I think sometimes if it's a dry year, whatever, they might not irrigate the full circle. And so, so, Is there a difference between the area equipped for irrigation and then what actually happens in that year? Do you take that into account?
[00:09:58] Kyle Davis: Definitely a difference. the maps that we develop aren't able to capture interannual variability or crop rotations or following anything like that. and that's, that's an important piece of the puzzle too. So I think our, our, the area, the information on area equipped for irrigation provides kind of a, a stepping stone for them understanding.
Okay. We were pretty confident that there's irrigation infrastructure in these places, but we don't know for a given year, whether the field is actually being actively productive and actively irrigated. And so, that's where things like remote sensing and other types of techniques become really important for, for understanding those year to year dynamics.
[00:10:42] Bridget Scanlon: Right. And you mentioned an important point, Kyle. following, if it's a drought period, maybe the farmers would fallow, but I know from, Claude, talking to Claudia Font, in the Central Valley, with all of the nut trees and their high economic value. Things that are going in, and these are perennial plants, trees and stuff, they can't fallow, and so they harden the demand and, and then they can respond like in the past where they would, it was an annual crop, they would just be able to fallow, and then respond to the drought, but now, with those, hardened demands, it's, it gets more difficult.
[00:11:18] Kyle Davis: No, I think that's a great point. Great point that, really defines the, the types of crops that are planted in a particular place, whether they're annual or perennial, really help define or limit the solution space that you might, you might be able to consider when you're thinking about improving the, the water sustainability outcomes for a system.
[00:11:37] Bridget Scanlon: Right. And, do you have an idea, from that mapping, whether the, irrigation sources, surface water or groundwater, or, if you're looking at the high plains, you would say, well, it's mostly the Ogallala aquifer. So you would know from that context, but, is there, can you tell, Because it really makes a difference, if you're irrigating with surface water sometimes and then groundwater other times, then you can replenish the groundwater with the excess recharge from the surface water.
So, these are all pretty complicated things, but I don't know, were you able to map or can you determine or just from experience people know?
[00:12:15] Kyle Davis: Yeah, I guess that's something that you need to combine with additional information to try and understand whether a particular location is groundwater surface water dominated, or to what extent there's kind of reliance on both. And that's, yeah, I guess that's kind of a next step for, for the work that my group is doing is we want to, we want to understand.
Globally, kind of the distributions of crop production and where, to what extent the production for different crops is exposed to different levels of water scarcity. and also differentiate that between groundwater dominated and surface water dominated systems. But then take it one step further to try and understand, okay, this, Fraction of production for wheat or this fraction of production for corn in the U.S. Is, being produced under water stressed conditions or in places where there's water scarcity, but it's not necessarily the U. S. Or the people in those places where the production is happening that are actually consuming or utilizing those crops. And so our next step is to then connect production and consumption, both within countries, but also internationally to, to understand, really what's kind of the, the risk profile of different countries, given their engagement with food trade and all.
[00:13:38] Bridget Scanlon: Right. And I know I keep harping back in California because it's so much written about it but, during a drought, they will use 70 percent groundwater oftentimes in the Central Valley, and then during a wet period, they may use 70 percent surface water. and that's actually good because then the surface water irrigation and now they talk about flood managed aquifer recharge or things like that, where they flood the fields in the winter, can help to recharge the, the depleted groundwater.
So all of these complexities are important to, but you have to take it a step at a time. And so I'm delighted that you guys develop these maps and really pleased that you make the data open access and the codes and the scripts. and everything. So, that's a huge contribution to the community and really appreciate it.
[00:14:26] Kyle Davis: I mean, I think it's kind of the direction that all of these global products are going is, fair guidelines, basically.in terms of data and code, which I think is great. I think it, it enhances the equitable, the equity across the, the entire community and allows for folks to kind of more readily adapt the tools to their particular purposes.
So that's exactly what we want.
[00:14:52] Bridget Scanlon: Right. And one of the things that I was interested when I looked at the maps in that paper, was that I think there was one map where you say where irrigation expanded sustainably and it seemed like, Brazil showed a lot of green and even the eastern U. S., more humid part of the U.S., so maybe more irrigation where there is more water available. Maybe you can describe that a little bit, Kyle.
[00:15:18] Kyle Davis: Oh, yeah. the main thing to keep in mind with that categorization of sustainable expansion is it's strictly related to water sustainability and water availability. So if there's cropland expansion and irrigation expand, like in the case of Brazil, if there's cropland expansion and irrigation expansion that's happening into natural systems, and there's widespread land use change that's happening. That's another dimension of sustainability that's being compromised, obviously. and so, yeah, I think that's that's something that that I'm really interested in understanding is okay. There are these decisions that are made and there are certain priorities that are, being focused on in influencing those decisions and the changes that we're observing.
But there's all these hosts of other outcomes that are that are potentially manifesting as a result of an intervention focused on that specific goal. so Brazil is kind of a hallmark example of that. We're in the maps that we developed. Brazil looks all green because there's plenty of water available in most places in Brazil to support that irrigation expansion, but that comes with substantial environmental consequences.
[00:16:32] Bridget Scanlon: Right. So, I was recently down in Brazil and, and so the Cerrado area, an awful lot of people talk about the Amazon forests and stuff and the issues there, but the Cerrado biome, which is a huge part of central Brazil and the Amazon. Yeah. Southeast,,there's a lot of agricultural expansion there.
And when I spoke to Esteban Jobagi from Argentina, agricultural expansion there, groundwater levels rising, flooding, creating rivers and all of that sort of thing. So, we kind of talk about things piecemeal, but,the cascading impacts of some of these things. but also, I think, I'm just wondering, in the eastern U.S. where it's more humid, maybe with a little irrigation expansion, I mean, they use the term in, in Brazil, I think, Salvation irrigation. So it's not a huge amount of irrigation, but with that additional water, do you really bump up the production? And so if there is enough water, maybe you're not going to nuke the water system, the sustainability of water.
And I think I've heard some people in the past talk about banks requiring people, even in Alabama and places like that to have irrigation so that they would be able to pay back their loans. So there are a lot of factors, insurance agents and banks and all of these things that come into play to the decisions that people make.
[00:17:49] Kyle Davis: Oh yeah, definitely. And yeah, I think, I think some of these global products offer you insights into the broad patterns of things. but if you really want to know why those patterns are manifesting, you really need to do a deep dive into the laws and policies and legislations and regulations and markets and economies all shaping why those things are, are changing. So, deep dives are required in particular places to really understand what the dynamics are.
[00:18:21] Bridget Scanlon: so you mentioned a little while ago that, you're,this past summer, this summer you have been working with people and applying machine learning, to try to develop a rapid approach, to develop these irrigation maps. and I think that's fascinating. a lot of people questioning, well, how much should we use data analytics and AI and ML to do things these days?
And it, it reminds me when I was starting off in my career 50 years ago, that, well, should we have a calculator? And the calculator costs like $250, Yeah.
or should we continue to use a slide rule? So I think maybe you can describe a little bit about what you guys are are doing in that space, using machine learning to help with mapping.
[00:19:03] Kyle Davis: Yeah. Yeah. I guess, just taking a step back, I think, I mean, machine learning, I think of it as kind of a complimentary tool to a lot of the existing approaches in the water science community. So I don't think machine learning is going to replace process-based modeling or anything like that. I think that machine learning helps to identify novel or undetected associations between things, but it doesn't describe the mechanisms or the processes by which they take place. So I think it's a really powerful tool, but as with any tool, it has its limits. but yeah, the, the machine learning work that we're doing related to irrigation is primarily meant to address this time lag in irrigation information.
So the traditional way The goal of developing these global gridded maps is you rely you, you gather, information from agricultural censuses, globally. And those occur only every 5 or 10 years. Some countries they don't occur regularly. and they. The information often gets put out two or three years after the data is actually collected.
And so there's all types of time lags that, that restrict how up to date global graded products can be. And so this, the machine learning that we're trying to do with the, it's meant to develop. a year 2023 right now global irrigation map at a very fine resolution. So we're using Landsat data primarily, which is a 30 meter pixel resolution.
so we're what we're doing is we're taking, the cropland products that are developed at the University of Maryland, based on Landsat information, and then we're assuming within we're assuming that those cropland products are truth, which we know that there's uncertainties and errors and those types of those types of products.
But then we're, we're looking at each pixel within that product and with, a variety of satellite information, things like NDVI and, precipitation, dry spells, soil moisture, a host of variables where we're making a determination for each of those pixels. whether or not it's irrigated, whether or not we think it's irrigated.
So the, the goal is to have annually updated maps of irrigated extent, so that we can see, okay, things like you're talking about where, where some years maybe part of a pivot is fallowed and other, other years that, that part is, So, that is, that is actively productive it with products like this, we can actually see, okay, how regularly is this field being utilized?
Is there multi cropping that's happening? so, so those, those types of, those are the types of advances that we're kind of working on in the machine learning area. And we're, the, the only point I'll add is that, right now we're basing it on the University of Maryland product because that's kind of one of the finest resolution one of the most reliable but as more cropland products become available the hope is that we can kind of apply our method in an ensemble way where we take different cropland products and then make determinations about irrigated or not irrigated so that it's not entirely dependent on the assumptions in our single Data product that we're using.
[00:22:26] Bridget Scanlon: I think that's fantastic. And I really like that you're harmonizing all of these different data sets. And that's the value of data analytics to help you. I mean, there's so much data out there these days and that you're combining vegetation indices and climate data, rainfall, temperature, drought indices, and then the soil moisture.
So trying to constrain then what's happening with so many different data sets. I think that is amazing. And then trying to reduce the latency with these data products, would be fantastic. We won't be able to keep up with you, Kyle, you'll be producing all these maps and we won't..I mean, the field of AI is moving fast, I guess. Right?
And I think it's a really nice way to harmonize data and so many different satellite products and everything. And so it's one of the few ways I think that we can try to do that. And I agree, won't replace process based modeling, but it's a good complement and we should avail of it. as, as much as possible.
[00:23:32] Kyle Davis: And, and the hybrid approach where you combine the process-based modeling with the, machine learning and stuff and data analytics, I think may be optimal going forward. Yeah.
[00:23:44] Kyle Davis: yeah, just 1 other point related to that. I mean, to your point about the difference between area equipped for irrigation and actually irrigated area products like this can allow you to see from year to year how things are changing and to try and understand how that's connected with climate variability, how that's connected with economic decisions and markets and food prices all types of things like that.
So, yeah It'll be kind of like open up a a new avenue of investigation. I'm excited about it
[00:24:13] Bridget Scanlon: and also help us try to understand food security concerns, and you mentioned earlier trade, but we'll get into that shortly. So, I think you had a paper beyond the green revolution, which was very interesting. And, we had, the population has grown a lot in the past and, the green revolution, Norman Borlaug and intensification of production, technology, fertilizers, crop selection, monocultures, all of these things to help increase, food production and irrigation was one of those aspects. And I think, Peter Gleick, used the term, the blue and green revolution, because he felt that the water aspect had such a big part to play with that. so maybe, you can describe a little bit because food production touches on water, energy and all of these other aspects and, and what you were describing in that paper on beyond the green revolution.
[00:25:08] Kyle Davis: Yeah, sure. So that was that was kind of the the capstone of a guest focused issue that that me and a few other folks led at Environmental Research Letters focused on sustainable food systems. and yeah, within that editorial that we that we put together we really kind of outlined three main aims of kind of where we see research going in terms of moving beyond the Green Revolution.
Obviously the Green Revolution was really important for increasing food production rapidly and avoiding hunger and famine in a lot of vulnerable areas. But there, as we all well know, there's lots of trade-offs that came with that. So in our editorial, we kind of outlined that first, there's a need to, understand how sustainability is defined and who has a hand in defining that sustainability.
and then the second aim is, okay, if you can come to an agreement on what those different dimensions or different factors are that, that define sustainability in a food systems perspective. How do you, to what extent can you measure those different dimensions? And are there new methods needed to to develop ways to measure and assess a suite of sustainability outcomes?
And then third, once you're able to measure that suite of outcomes, how can you use that to then identify solutions that maximize co-benefits across those dimensions and minimize trade-offs. So that's fundamentally kind of steering the research towards, there, there's more and more work being done that's holistic, but pointing research towards these multi-dimensional or holistic considerations that, if you ultimately intend to do solution testing, you really need to know how that solution is going to cascade through to other outcomes and other dimensions, even though the solution itself may be promising for, for the particular indicator, the particular dimension that you're really interested in.
[00:27:22] Bridget Scanlon: Right. And I think oftentimes, our thinking can be siloed. I mean, I know getting onto a plane, you're walking down the gangway to the aircraft and you see all these things on the side, United is sustainable aviation fuel and everything and sustainable for the energy sector, but maybe not so much for the water sector because maybe they have long term contracts with the corn production in the Midwest. And that might heavily impact the water resources. So I think it's important to consider the trade-offs and, and more and more people are more focused on one aspect and, and then don't consider the negatives. And, and I think trying to optimize the co-benefits and reduce the negative impacts is, is a really nice approach and, and putting it in a larger context.
[00:28:11] Kyle Davis: I think that's ultimately what decision makers and policy makers are looking for. They're looking for kind of all of the information laid out in front of them to understand, okay, really, how are these, I need to take into account multiple considerations when making a decision. And so the extent to which I think researchers can do that, the more kind of linkage there will be with the policy or decision-making communities, just naturally.
[00:28:37] Bridget Scanlon: Right. Well, I think sometimes, they're so focused on energy sector or greenhouse gas emissions and let's do it at all costs to anything else, or land or water or other resources. So sometimes I think they are pretty siloed. And so, but I mean, as researchers, I think it's important for us to provide, the broader context, also, so, Kyle, I know you go back and forth to Africa quite a bit and, and you've been working in Nigeria and Africa, I think people kind of forget that Africa, global demography is going to change a lot in the future.
I mean, currently, population in Africa is about 1.4 billion, similar to India and China's population, but the projections are, that it'll exceed those other countries and maybe 2. 5 billion in Africa by 2050. Nigeria is kind of the poster child for that big population growth and, and how are they going to manage with food and water and things like that.
So, maybe you can describe some of the programs that are happening there and how you see it evolving as it may be a template for how Africa may try to cope, in the future. Right,
[00:29:55] Kyle Davis: I think, I mean, speaking from my experience in Nigeria, there's lots of opportunity and potential for enhancing food production and moving towards self-sufficiency. And I think that's true for a lot of other African nations. Nigeria, yeah, by the middle of the century, it's supposed to be the second or third most populous country in the world.
So there's really rapid change that's going on in the country. And even the past, I've been going there for close to 15 years now. And even just in that short period of time, I've seen really massive changes in terms of urban expansion, land use conversion,ind of a rising of middle sized and commercial sized farms. And so yeah, they're just at the beginning of increasing production, being able to infuse technology into agricultural systems. And what I think is maybe going to be one of the most difficult things to navigate. I mean, I think it's maybe a little clear and a little more straightforward in terms of technology transfers and building out value chains and, making sure that kind of the technology and innovation side is there to support that but there are big societal shifts that are potentially on the horizon. There's the farming systems are dominated by small holders. There's very little irrigation that's happening in Nigeria. And so I, I think one of the most difficult challenges there is going to be, okay, if we want to rapidly increase the productivity of crop production in the country, and we see a more commercial style agriculture as being the pathway to that. What does that mean for all of these small holders whose livelihoods rely on it and who don't have many times formal legal claim to the land. And so I think that in addition to thinking about those, those pathways towards, okay, how do you increase production?
How do you do it in a way that ensures that everybody's brought along? And that's, that's maybe one of the ways in which we can learn lessons from the green revolution too. So, so yeah, I think the, those two pieces I see as kind of the piece about technology and facilitating technology transfers and access to technologies kind of across an entire country, but also ensuring that rural communities and rural rural livelihoods don't just evaporate or, get brushed to the side. Those are the 2 main challenges. I see.
[00:32:43] Bridget Scanlon: Right. And so, I mean, when, when you visit Nigeria, do you find that we hear a lot about increasing urbanization and maybe, that the smallholder farmers are having such a difficult time that, maybe they don't want their kids to be in farming. Maybe the kids are going to the cities and stuff like that. So, going forward, maybe there won't be that many people to support the smallholder farming. And, so maybe consolidating the farms to some extent and making moderate sized or, and, and the technology is a big issue for Africa. I mean if you compare Africa and India, India is very innovative in advancing technology a lot, but in Africa, it seems like you have to import everything, and that just adds a huge cost and, and, and complexity, to the whole thing.
So, you mentioned, I think, the World Bank is trying with some of these programs that they have. I know I was familiar with the farmer led irrigation development, which was focusing on smallholder, but you also mentioned. A project in Nigeria called SPIN, and you know how these, projects are trying to help the communities, improve food security.
[00:33:53] Kyle Davis: Yeah. Well, I think that's a project that's under development. I'm not sure. It's fully been initiated within the country. Yes. Spin S. P. I. N. I forget what the acronym stands for, but it's about sustainable irrigation expansion and, the installation of additional and rehabilitation of irrigation dams across the country and irrigation infrastructure.
I think with those types of programs, I think they're critically important, but I think that they need to be again more holistic and maybe cast a wider net in terms of the things that they're considering to really reap the benefits of a project like that. Just from the irrigation dams that I've visited, many of them were created to enable access for smallholders to supplementary water but then it can be an issue. The way that the farmers access that water is through handheld diesel pumps. And so it can be an issue that farmers aren't able to afford their own diesel pump. It can be an issue that, they collectively, they're not able to afford to rent the diesel pump. There can be changes in fuel prices for the diesel pump that compromise, like even if a farmer has a pump, it may become unprofitable for them to use that pump because the cost of fuel is so high, which is what we've seen in Nigeria over the past and so I think that, supporting that within the portfolio of a project like that, I think is just as important as the creation of an irrigation dam itself, being able to, and I think also take carefully considering what it's going to imply if you establish an irrigation dam in a place where there's primarily smallholder agriculture that's happening, are you going to, encourage investors to come in and consolidate that land potentially, and potentially displace those smallholders? What are the rights of those smallholders? What alternatives or solutions. Have you come up with that? If a scenario like that arises, that's going to support them and make sure that they have opportunities elsewhere, potentially, and that they're consulted before the project.
All of those things, I think, are really important to a company, a big infrastructure installation like that
[00:36:20] Bridget Scanlon: Well, I think, we both work on the physical science side of things, but I mean, I think I really like that, organizations like NSF and others are, are pushing us to collaborate more with social scientists and and to consider the social implications of many of these decisions. And so, yeah, we might bring in a fix it solution, and then completely disregard socioeconomic aspects and things.
So I think very important to consider those. And also, behavior. I was talking to Nick Brozovick recently, and he was indicating that some farmers were accustomed to using surface water, and they would transport it for long distances, and they wouldn't even dream of drilling groundwater well, because it just wasn't in their DNA.
So, we need to consider these aspects also in addition to coming in with our solutions and saying, Oh yeah, you could just do this, it's very complicated. But, it's great to get the data there at least and so important to provide that. So, I was just at a conference in Brazil and, I, I heard the presentation where somebody said that they could, rovide Brazil could provide enough food to feed another billion people in the future.
And,we know that they grow a lot of soybeans and, and trade a lot with China and, and, there's a huge potential. I know you mentioned deforestation and things like that, but, I mean, in some of your papers, you show promise, in Brazil and, when you map the irrigation expansion.
So, and that gets into, global food trade issues. And if countries are okay with relying on trade and, and you've looked at that a lot in your work also. So, what are your thoughts? I mean, we've just come through COVID. Everybody wants to be food secure, water secure in their own countries and stuff, but then a lot of countries rely on trade. What are your thoughts about some of those, those aspects?
[00:38:19] Kyle Davis: In terms to the point about Brazil, maybe being able to feed a billion people. Maybe that's true. I don't know. But, it's all about the trade-offs, right? So there's going to be, you need to really intensify agriculture, more fertilizers, more greenhouse gas emissions, more water use, more potential ecological impacts, and then who is the food for?
Or who are those crops for? May not even be for food, but who are those crops for? is it being utilized? It's partially in the countries and being presumably much of that would be produced to be sent elsewhere. So all of those things I think, yeah, are really important to consider in a target or goal or, a ceiling like that.
But yeah, in terms of, in terms of food trade, I think, I mean, it's critically important. I think it's about greater than three quarters of nations globally are net importers and yeah, as we know, going to the grocery store, there's all types of food products that are available in the grocery store, and those things, Some of them may be grown locally, but many of them can't grow in the soils and climates in the United States.
So they need to come from somewhere else. And so, food trade is more and more important in meeting these kinds of international dietary demands that we have. And yeah, I guess. Food trade, it's a bit of a double edged sword as we've seen with COVID and as we've seen with other kind of recent, economic and, political crises that, on one hand, it can help to increase the capacity of a country to support itself.
So maybe the local resources in a country are only able to produce the food to support one fraction of the population and it's required to import food in order to meet all of those food demands. So, in that way, you can play a real, it can be of great benefit from a food security perspective, and it can also be a benefit from a climate resilience perspective.
For certain types of climate effects that may affect a country's local production and they need ways to buffer shortfalls in production, then international trade obviously allows for them to compensate for that. But the other, the other side of that is then countries start to become exposed to disruptions that are happening beyond their borders and beyond their control.
We have environmental examples. We have, political examples of, of those types of things cascading through, cascading globally where one or two countries are the ones that are actually being directly impacted, but because of those impacts, they're no longer able to produce as much of a certain crop and export as much of a certain crop.
And so for countries that are heavily reliant on individual linkages in the food trade network, those types of countries in particular can become very vulnerable to international or global disruptions, I think.
[00:41:31] Bridget Scanlon: Right. I really enjoyed your paper on food supply chain resilience and, to environmental shocks, and, and how those shocks can propagate and what their impacts can be. And, so was recently talking with Yoshi Wada from Saudi Arabia and looking at their food trade. They're importing from many different countries, Brazil, maybe mostly, but also US and Australia and everything.
So by importing from a number of different countries, maybe that enhances their resilience and then to one country, going off. But also it may be the poorer countries that are exposed to these shocks, because I mean, there could be price increases when there is an environmental shock and some food is not as readily available. And then the poor countries may be less able to afford those price increases. Whereas the rich countries can maybe navigate around that.
[00:42:23] Kyle Davis: Or, yeah, yeah, I think there's some recent literature showing that richer countries basically get to go first in line when it comes to rearranging trade networks in times of crisis or disruption. And so, yeah, oftentimes it's the countries that are potentially most vulnerable and most food insecure are the ones that have the most difficult time in navigating those types of teleconnected disruptions, right?
[00:42:53] Bridget Scanlon: Right. And, some of your work also many of your papers focus on optimizing crop distribution. I mean, there are different ways we can try to resolve food issues, we can, what we've seen, we bring the water to the food like in the Central Valley. So we have many other aspects that are are good: climate and good soils and everything.
So we transport the water or we overexploit the groundwater in the interim to, to generate the food there. Or, we could take the food production to a wetter climate. I mean, World Wildlife Fund was looking at could we move the Central Valley to Mississippi? And, and emphasizing the social aspects and the pests and other things, so one of the things that you talk about, and also Brian Richter, I think, is, optimizing the, the crop selection, to improve, sustainability from a number, of different, perspectives, I think maybe just water, land and other things.
So maybe you can describe that a little bit. I know you've had papers on China and India and other regions also, where they could switch some crops and then improve the sustainability.
[00:43:59] Kyle Davis: Yeah, and I guess the that work is it kind of stems from observing cropping patterns in different countries and, seeing that, yeah, obviously they're contributing to unsustainable water use and a number of other undesirable outcomes, and thinking about are there ways to maintain those levels of production, but do it in a smarter way that, reducing environmental burdens.
Yeah, we, we've done work in China where we've looked at, a number of different environmental dimensions and to what extent crops can be shifted in existing croplands. So we set constraints that cropland can't, it's the overall extent of cropland can't change the levels of production for each of the crops can't change at a national level, and then we, we say, okay, if we, increase the harvested area allocated to certain crops in these places and decrease the harvested area allocated to crops in places where these crops are already grown, to what extent can we reduce greenhouse gas emissions, reduce blue water demand, reduce pesticide use, reduce fertilizer use and enhance farmer's incomes.
Kind of, a multidimensional set of outcomes. So, we were able to find that in China, there's substantial opportunity to be able to do something like that. and it would contribute pretty meaningfully to some of their agricultural sustainability targets. So, so in a place like in a country like China, a national level shifting of crops like that is maybe realistic given that it's kind of a central planner government and they can take stock of the full picture and pull all the levers at once.
So, so that was what we looked at then as you mentioned, some work with Brian Richter focused in the U. S. we looked at, to what extent can you shift cropping? To what extent can you switch crops that are currently grown in particular places in order to reduce stream flow depletion and maintain maintain levels of production? And maintain farmers incomes. We looked at six different, kind of stressed river basins across basins across the US and performed a set of kind of spatial optimizations to see where you might reduce alfalfa, where you might increase barley, where you, where you might, move around all different types of crops at the same time and tried to quantify to what extent can you actually, potentially save water in doing so.
[00:46:48] Bridget Scanlon: Well, that's a really nice optimization analysis, and I know from working with folks at the North China Plain, they grow a lot of winter wheat and the winter is a time period where there's very little rainfall, so that's heavily irrigated, but the summer maize can take advantage of the rainfall. Switching these crops and trying to optimize, I think is really nice and probably has more potential there where they may be more, top down, control and that sort of, and, and I recall in that paper that you indicated that, that the water demand could be reduced below renewable levels in the Sahel region of Africa.
And maybe you could describe that a little bit.
[00:47:33] Kyle Davis: Oh, yeah. That was that's from a separate paper. That was. like a global optimization of cropping distributions, a real kind of thought experiment type analysis to see, explore the solution space really. But then we looked at, okay, to what extent can you move crops around? What are the implications for calorie production? What are the implications for reductions in blue and green water demand? and then what does that imply for water scarcity. So the ratio of consumptive water demand to renewable water availability taking into account environmental flows or or water that's needed to support ecological needs. So, yeah, in this Sahel region, and in a number of other regions, I guess we found that, through some of these, crop switching interventions are optimized kind of geospatial cropping patterns that you could substantially reduce the water demand to a point where you start to flip from conditions of water scarcity to unstressed conditions.
[00:48:40] Bridget Scanlon: Yeah, well, that's that's fascinating. I wish we had more time to chat, Kyle. I mean, you've done so many different things. We've only touched briefly on many different topics. I know you've done a lot of work on land grabbing and migration and all of these things. But unfortunately, we're running out of time.
I really admire your work. I mean, I think, the data that you're developing and with reduced latency, the irrigation data and making all that available and, using advanced tools like data analytics and stuff with traditional approaches and combining all of these different satellite data is amazing.
And so that would be huge help to people trying to figure out what's going on. And I'm impressed that you're working in Nigeria because I mean, the more insights you can gain from there, which could be a template for much of Africa. I think trying to enhance food security and water security in sub Saharan Africa is a huge issue.
And so it's great that you're working there. And so, focusing on solutions, the solution space and looking at all different options is fascinating, looking at the trade-offs and the co benefits and everything. So that's really cool. so thank you so much, for chatting today and, look forward to, to keep learning from your work and your group and wish you the best.
[00:50:01] Kyle Davis: Thanks so much for having me. The admiration goes both ways. so thanks. Thanks again. and I really, I really enjoyed the conversation.
