Friday, August 26, 2022

An Interview with Norm Crawford: Inventor of the First Computer Model of Rivers

The tops of the curvaceous hills above Stanford University look like someone caught in the middle of shaving. There are occasional patches of forest here and there, but the Open Space Preserves above the Portola Valley are mostly grasslands. Up close, one can stand in a single spot and see tall grass, lonely shrubs, lush ferns and twisted forest. Near the peaks, there are no flowing streams, but plenty of mud and moss in the shady areas. In places, the hiking trails have gouged away at the land, exposing rocks and soil.

The Windy Hill Open Space Preserve in the hills above Stanford University
The rocks are exposed in some places
A path through the nearby woods
Close-up of lichen growing on the trees

Steps away from open land, mossy trees cover the pathway.

There are innumerable ways to measure out this landscape. The tallest peak is 1,905 feet high. A cup of soil beneath my feet weighs about two thirds of a pound. This spot is about a 40 minute drive from San Francisco (depending on traffic). With its infinite detail, reading aloud an inventory of the land could conceivably take forever. These exhaustive descriptions would not even include all the aspects that are changing. “Here a fallen tree is half decayed.” “After Wednesday's rain, there are 73 puddles left along the trail”.
These descriptions wouldn’t even be possible, anyway, since most of these details are unknown; some modern geologic maps of the San Francisco Bay Area are humble enough to include question marks in certain locations.
Science is about simplification and summarizing, however. There are so many details in the landscape, but which details are important? “Importance” naturally depends on purpose. For someone wanting to drive through the area, the roads are what matter the most. Descriptions of every inch of pavement are not even necessary, but rather knowing the length of roads and how they connect are probably enough for finding one's way.
Similarly, someone wanting to know how a stream flows could use a hydrologic model. Around 50 years ago, in the valley below Windy Peak, Norm Crawford was the first person to use a computer to simulate a river. Much has changed since then. My small laptop in 2010 is about 100 million times as powerful as the 1960s computers. Printers, alone, at this time were half the size of an automobile. Now, computer models are a nearly indispensable tool in river forecasting. What Norm developed (the Stanford Watershed Model, named after his Alma Mater) continues to evolve and is still used around the world. In particular, it forms the core of many water quality models.
Even though Norm was there at the birth of river simulation modeling, he still keeps a hand in the game. His consulting firm, Hydrocomp, makes river modeling software, sets up modeling systems and provides other services to government and private industry. He gives talks at international conferences, offering seasoned wisdom but also ambitious vision.
During a recent talk in Peru he ran his model in real-time “on the cloud” (i.e. through the Internet) rather than on his own computer. Decades ago, he would have had to schedule time with the computer operator to submit a job to run overnight. Norm has said “People underestimate what’s possible not only at the present time but in future time. My philosophy…is to build software systems that anticipate hardware that isn’t here yet.”
Norm and I met in the Netherlands last year to share his ideas on models and reflect on what he started. Earlier that week, we had participated in a workshop of hydrologists interested in testing ways to make river forecasts that are honest about their uncertainty. It was something like a “bake-off” where everyone brought their own technique to the table and applied it on a common dataset provided by the organizers. We were asked to pretend that we were making forecasts in a semi-realistic way (i.e. no peeking at the answers) so the results could be compared. In total, the team from CSIRO (Durga Lal Shrestha and I) churned out roughly ten billion forecasts by harnessing a network of thousands of desktop computers in Australia.
This week will include a series of posts with excerpts of our three-hour interview and some of the discussions that followed. Norm’s story has been chronicled a few times in the scientific literature, such as the History of the Stanford Watershed Model and a chapter from the book Watershed Models although these focus more on the connections between different researchers and how the original “DNA” of the Stanford Watershed Model can be found in other models used widely in the community. My comments and questions are in blue and Norm is in black.   
This interview has several parts, click on a link to jump ahead to that section:
What is a computer model?
What are these models used for?
What did people use before Norm Crawford invented the first river simulation model?
How did he become the inventor of the Stanford Watershed Model?
How does someone build a computer model?
Can models mislead people? Can people mislead models?
What is a computer model?
Norm Crawford: It’s the numerical equivalent of a physical simulator built to represent flying of a 747 [airplane]. If you were trying to be a pilot, you’d go and sit inside a reproduction of the [cockpit and its controls]. You can land and take off, and it recreates the entire environment of flying a plane... If you crash the simulator, nobody dies and you don’t lose a multi-million dollar airplane.
Digital simulation models represent the hydrologic processes that occur in a watershed. Measure one is moisture in the soil – when rainfall occurs, this computer model will calculate whether it infiltrates into the soil or [becomes runoff] as the soil becomes more saturated.... Then water, if it does run off, moves into a small tributary and then maybe into a larger tributary and is measured downstream at some stream gauge. And the computer model calculates the hydraulics of movement of flow into channels along the river until it gets to the stream gauge.
These models are calibrated [tuned to improve the results] by changing parameters that represent infiltration rates into the soil, rates of evaporation loss from the land surface, and transpiration from vegetation. It’s keeping track of what is referred to as a “water balance”. The model is just tracking a raindrop from the time that it falls and hits the ground, and then it keeps track of what happens to it to the point where it either evaporates or it flows in stream and flows out of the watershed that you’re interested in.
Tom Pagano: ...A lot of hydrologists would think of soil as being like a sponge...When it's dry and you put water in it, the water just soaks right into the sponge, it doesn’t leave. But once the sponge is full and saturated, any more water you put in will erupt over the top or drain out the bottom.

These models are a set of equations that describe how the water would flow through the sponge. When you talk about parameters- that’s how you relate those general equations to your specific catchment, like how big is your sponge, what's the texture of your sponge?

Norm Crawford: Right. Is it an open sponge with large holes in it or a dense sponge that doesn’t absorb much water?
Tom Pagano: Who would use these models? What would they use them for? You mentioned a flight simulator [for training pilots]; was it a teaching tool?

Norm Crawford: Initially, we did use it quite heavily as a teaching tool. It was a very good way for students in hydrology to get a feel for the way a watershed would behave. And we actually built a classroom, probably the first in the country, maybe the first in the world, where we had computer terminals that would link to the Stanford University mainframe. Students could assemble some data for rainfall, evaporation on a watershed, and then change the character of the watershed surface, like change the infiltration rate, to get an immediate response back as to how the watershed was dealing with the rainfall.
[Nowadays, hydrology models are used very widely, inside and outside universities. As mentioned above, they are used for teaching, but they are also used for academic research. They are also used by consultants, engineers and a host of other professionals.]

What did people use before Norm Crawford invented the first river simulation model?

Tom Pagano: Were there river forecasts before computers?

Norm Crawford: Oh yeah, sure. The standard methodology was called “coaxial correlation”. It was a big piece of paper with a series of lines on it and you would enter a amount of rainfall, an index called an API [Antecedent Precipitation Index], and a drainage area, and it would kick out a number [for the flow of the river].
[An API is like a index of how dry the catchment is, how much water is in the soils. For discussion of something similar to coaxial correlation, read about Manila hydrologists using such charts to forecast runoff from a typhoon]
Norm Crawford: The professor [Ray Linsley] that I had actually developed [the API] for the Weather Bureau and for the stream forecasting service. And he had spent some years doing flood forecasting. He was also the head of civil engineering in Stanford at the time, and published [the books “Applied Hydrology”, “Elements of Hydraulic Engineering”, “Water Resources Engineering”, and “Hydrology for Engineers”, the last two of which are still in print].

Tom Pagano: So [the forecasters had look-up tables as a way of converting rainfall to runoff]. Someone would phone up with the rainfall amount for certain areas... or was there real-time [automatically transmitted] data?

Norm Crawford: There was real-time data collection in a way. I remember Professor Linsley telling us about [river forecasting] in class one day, and he said this activity is done 24 hours a day, in the middle of the night, and on weekends. If heavy rainfall is occurring, flood forecasters are on duty trying to figure it out. And one guy in class said “why are you telling us about that?”, [as in:] “we’re not going to work in the middle of the night, you’re crazy!”. It was a typical student wise remark.
But the real-time data collection; they did have devices on some rivers based on the telephony system and you could call up and you’d get a beep response from a sensor. You could translate that [like Morse Code] into a stage [river depth] that was being measured at that location.
One story that Ray [Linsley] told was about one of those remotes gauges… It was the only way that they could get that kind of information in [to the office], in time to be useful. Now, on a really large river, you could depend on somebody observing the stage [river depth] and calling you, but they did have these other devices where no human needed to do anything except call a right number. And they had a gauge that was giving frequent false alarms. The little beep system wasn’t working very well.
And so this one day they called this gauge and it reported that the stage was five feet higher than normal. And in the flood forecasting office, they thought “well, that darn gauge is misbehaving again” and of course about three hours later the flood peak arrives and they realized the gauge was telling the truth.

How did he become the inventor of the Stanford Watershed Model?

[I asked about Norm's early influences and what shaped his thinking at the time. How did he get interested in science and computers? What was the context for his invention?]
Norm Crawford: I was born in the mid-1930s, and I grew up in Western Canada on the family farm and then in a small town of 1500 people. My family was basically farmers, although one of my grandfathers was an early graduate from the University of Ontario, and he was a minister.
He moved to Alberta in 1908. Prior to radio or modern communication one of the recreational activities was for people to go to a community hall to hear someone lecture. My grandfather was one of the few educated men in the countryside, and (although he was a minister) he would lecture on astronomy and geology and politics. He was a college graduate and was an educated fellow. He had that kind of knowledge that other people did not have. And moreover, he was a very entertaining speaker and very outgoing.
There was a defence line across Northern Canada to protect against Russian bombers flying over the pole with atomic bombs. There were these air bases with radars built in the middle of nowhere in Northern Alberta and the Northwest Territories. They were supposed to detect planes coming in, and they had fighters that would go up and engage them. One of the air bases that I visited with a number of other engineering students [from Alberta] had a very early and relatively small digital computer. These guys sitting up in the winter in that climate wouldn’t necessarily have a whole lot to do so they programmed that computer as an Artificial Intelligence [AI] machine. You could type into a typewriter and ask it questions like “how are you today?”, and the computer would answer, “I’m fine, how are you?”
The early AI code could play checkers and talk to you in its fashion. One of my classmates was a very clever guy and he managed to defeat the computer at this one game, and the computer said “Wow, I can’t beat you!”
Tom Pagano: And since it hadn’t been programmed to say that, it was truly remarkable! [laughter]
Norm Crawford: So that opened my eyes of possibilities that these machines had. I then went to Stanford University, a pioneer among universities in computers. This was an era [where some saw a limited long-range demand for computers]. Perhaps a few offense labs and maybe a bank or two and that was all the computers that the US would ever need. Stanford had one of those machines and I took a course in [computer] programming.
[The professor remarked that] revolutionary events happened in the way humans operate because of changes in speed. The impact of steam locomotives was such that you could build a railroad that would run fifteen times faster than a horse and carriage. That caused a revolution in a way that goods and services could be delivered around the country. He had a couple of other examples of the same kind.
He said already the few computers [that existed in 1958] operated 100 to 1,000 times faster than one could operate the huge mechanical hand calculators (that could add, and subtract, and multiply with some difficulty). The concept of stored memory also meant you didn’t have to punch the keys to add two and two, but you could put in an instruction to do the addition.
His statement [about changes in speed causing revolutions meant] changes in the way engineering science was done. Methods in engineering and science were tailored to the calculation speed that was existing. You could think of doing some calculation that would take ten years of typing, but you couldn’t actually do it.
His feeling was that new methods had to be developed to take advantage of this orders of magnitude change and speed of computation, and that the old methods were simply obsolete. I thought, “wow, that’s true that things have to be entirely different. You couldn’t just do the old things in your old way”. It was trivial to use an engineering method designed for pencil and paper and put that on a digital computer because it would take a digital computer no time to do it. However, you wouldn’t get a better result than doing it on pencil and paper [just quicker] so why do it that way? I thought that was very neat idea....
[Norm later recounted how he chose his graduate research topic. In his first year at Stanford University, he started working on an existing project that was trying to estimate the size of floods on small basins. The project was not very successful- the methods were not correct, the results not very good and the funding was ending.]

Norm Crawford: So [Advisor] Ray [Linsley] told me, “to heck with that stuff, just forget about it… why don’t you move to electrical engineering and they’ve got something over there called a digital computer. Well, I jumped on that because I was interested in digital computers. I went over and found a small room in electrical engineering where they had an IBM 650 machine, one of the 50 that existed in the country.
So out of that I started developing a methodology for representing the rainfall and runoff in river basins. I chose to do this in a way that [took advantage of not having to do the calculations by hand]. Repetitive computations were unlimited, as if you had this assistant who would calculate anything for you, and it didn’t matter how long it would take him because you could hardly think of anything that would take him terribly long. Running programs would take 10 to 20 minutes, and we had to sign up to use this machine. You’d go in and you’d actually operate the digital computer yourself, which a few years later was not allowed. The big deal about it was that the computer at the time cost $200 an hour in 1950 dollars, so that was a lot of money [and it was paid for by the National Science Foundation].
So I developed, as a PhD thesis, the first continuous digital computer model called the Stanford Watershed Model. It was the first of its kind and nobody really knew what to make of it. When I published my dissertation, it did receive some attention (that was in 1962). In 1966, I published an update to the model that was very widely distributed around the world. Some 10,000 copies of this technical report were published and distributed by the University. That became the foundation for continuous digital computer models.
[As a side note, the famous technical report describing the model calls it the “Stanford Watershed Model IV.” Model I was a daily-timestep model that apparently did not work very well. Model II was Norm's dissertation (which had an hourly-timestep). Model III was an unpublished incremental change in the model.]
Initially, people didn’t really quite know what it was. One person at a technical meeting around that era told me that it would set the science of hydrology back by 50 years… and he was serious, too! I can understand why he felt that way.
Tom Pagano: So we’re probably just recovering now?
Norm Crawford: Well, maybe never have recovered.
How does someone build a computer model?

Tom Pagano: You could say these models were a way of learning about reality [i.e. for use in the classroom and in doing research]. But at the same time, you had to put someone's idea of reality into the model. How did you figure out what should go in the model?
Norm Crawford: Well, there were two elements to it. One is what might be called the model structure... the physical processes that you choose to include in the model [the other element to model building is algorithms, which is discussed elsewhere]. A feature of the Stanford model was that it was comprehensive, including both surface and sub-surface flows. Previously, the common way of doing things was, if you were dealing with floods, to just worry about the surface runoff or immediate runoff.
But the Stanford model took the approach of representing all of the processes. And also, the common way of doing calculation for a flood, for example, was you would just calculate during the flood. After the rain stopped and evaporation started to occur, you just forget about it, and wait until the next flood. But the Stanford model operated continuously, and that was unique.
Tom Pagano: So in for metaphor of the sponge, surface runoff would be water flowing up over the top of the sponge that couldn’t get in. Base flow or subsurface flow is what’s draining out the bottom. During floods there’s lots of water coming out the top, and you don’t really care what’s coming out the bottom?
Norm Crawford: Yeah. Base flow is usually relatively small, at least in a major flood. Hydrology is full of exceptions, so what I just said is not always true.
Tom Pagano: Right. So how do you make a model if hydrology is full of exceptions?
Norm Crawford: Well, you represent the physical process as best you can. If you cover conditions that represent 98 or 99 percent of all the watersheds in the world, then that’s good enough for work, even if there are 1 or 2 percent that don’t work that way.
A major example is that for most watersheds (like 99 percent) there’s a strong relationship between moisture in the soil, and the infiltration rate (the rate at which water will move from the surface into the soil profile). Dry soil takes much more water than a saturated soil profile. And so the rate of movement of water from the land surface into the soil can change by two to three orders of magnitude from dry to wet....When the soil profile becomes saturated, you’ll get lateral flow that moves water... down a slope gradient [i.e. out of the soil and up on to the surface as it goes downhill].
[To put it another way, there's two effects going on here. Soil that is dry (“empty”) has more room to store new water in it. When the soil is wet, there is not as much room for additional water. Also, new water goes into dry soils relatively more quickly than it goes into dry soils. Think of it like someone eating until they're full. Someone with an empty stomach can eat a bigger meal than someone with a half full stomach. Also, as the person gets fuller, the rate that they can eat gets slower and slower. If the person can’t eat fast enough, food spills all over.]
Tom Pagano: So what happens to that other 1 percent [where the standard model of soil moisture and runoff doesn't apply]?
Norm Crawford: You say “too bad”! There are two conditions where this happens.
When you get into permafrost (areas of continuously frozen ground), the relationship between moisture and soil and runoff just isn’t there… It doesn’t work that way. The runoff will be more associated with temperatures. You might get a warm rain and only the top two or three inches of the permafrost may be frozen, and you get a lot of runoff like it’s flowing off of concrete.
The other [exception] is that there are some soils that become hydrophobic [water repellant] when they become extremely dry. That happens in desert areas. That water will bead up like water on windshield of your car, and it will form dusty drops, and those drops just roll across the surface, and the soil profile doesn’t pick it up – it effectively blocks infiltration in the extreme; the soil is totally hydrophobic. That second phenomenon is usually somewhat intermittent. And then the whole thing will switch, the soil profile’s hydrophobia goes away and all of a sudden it switches to acting in a more normal fashion....
Tom Pagano: You developed this model, based on some idea of how the world works. Did you ever find out that you were wrong, or that some part of the model doesn’t work? Do you ever get rid of parts of a model?
Norm Crawford: Yes. There’s almost a continuous process of trying to improve the model. In fact, we made significant changes in parts of the model a couple of months ago when we were doing some things with snow melt and snow heat exchange. [We did a process of improvement of the soil moisture model between 1960-1966] when I first started building that model, but then not many changes were made in the detail of how that’s done. After [1966] there had been considerable change [in other parts of the model], but that original core of the way the soil moisture and infiltration worked has not changed because I couldn’t find any way that it would work better.
Can models mislead people? Can people mislead models? 
[River forecasters often refer to model outputs as “guidance”. The phrase implies that the models can inform the forecast process, but shouldn’t have the final say on the product going to the customer. However, there are varying opinions about how much model outputs should change a forecaster’s mind, or how much a forecaster should use his mind to tinker with the model so it gives a better answer.]
Tom Pagano: What’s your feelings about the relationship between people and models in that sense?
Norm Crawford: Well, you don’t change [model] parameters in the middle of a flood. Model design is such that the parameters are supposed to be constant, and they’re developed by continuous simulation over a long period of time including a number of [historical] floods of different characters and so on.
The major thing, on the set of major flood, is that people are pretty shocked by what’s going on. And people will often be sleeping on the floor of their offices, making decisions that are unlike anything that they’ve done before.
In Tuolumne River [in California] in 1997, just right around Christmastime, there had been quite a lot of heavy rain. There was a series of storms that are known as Pineapple Express storms, were coming in off the Pacific into California.
The man who was responsible for Don Pedro Dam (which is a 600 foot high earth dam on fourth largest lake in California) was busy checking with the forecast office. He was told that there would be a break between the storms, and he figured he could go home and not worry about it for a couple of days. This turned up to not be true, and they started to get very heavy rain. And they were getting rain at high elevation as opposed to snow, which makes a great difference. And this man was busy running models and he was seeing risk [of failure] to the dam, and the dam at that point had been build about 30 years prior and had a large spillway. The spillway had never been used.
Sometime in that three day period, he’s talking with the head of the agency (Tuolumne Irrigation District owns the dam), and he’s talking to his boss. His boss was asking “are you sure about these numbers?”, “are you sure this has happened?”. [The dam manager] was saying “that’s what’s going on, we’re getting this huge flows coming out of the upper river!” And so they opened the spillway for the first time ever, wiped out a [well used] road immediately below [the dam]. The amount of water coming out tore out a 150 foot wide, 20 foot deep channel immediately. It took all that soil and just took out and caused flooding downstream in the city.
Events like that become legendary [and stick in the minds of water managers]… The first time that spill way was used, and [the operator] sleeping on the floor of his office for three nights. For people who make that kind of decision, it becomes a combination of “I hope I never have to go through that again in my life”, which is pretty likely that they won’t have to. And “it’s also very exciting time to go through”.
Tom Pagano: Maybe even there’s an addiction to the drama –
Norm Crawford: Yeah, it might be addictive, but it’s not something that you can readily form an addiction.
Tom Pagano: …We were talking about guidance and models and whether humans should trust them or try and change the model results…You’ve got an idea of what you think the model result should be, and maybe you adjust the model to make it match how you think it should behave. But then the rest of the result you get is [given to you by the model. For example], say you know what the peak flow should be, but you don’t know how quickly the river is going to drop after the peak… You let the model articulate all those other things that you don’t have time to figure out?
Norm Crawford: Well, I’ll tell you another instance. We have a model on a river in Southern California, with a fairly large dam upstream. A large flood developed – again, something bigger than anybody has seen in their lifetime. Based on model results, the downstream town’s Mayor and police department were told that they would expect the stream to go out onto its floodplain. Also, there are a number of people living there, and they should expect the peak to arrive in about eight hours. The Mayor was a fisherman and he knew from fishing in this river that if they released flow with this dam it would take 24 hours to get to the city.
So he told the police department “Relax, I know what the river’s doing, don’t worry about evacuating anybody”. What of course he didn’t know is that a high flow moves much faster than a low flow. The flood arrived in eight hours. It was pretty dicey. They had to go in and get people under emergency conditions just because the mayor didn’t understand channel hydraulics.
Should users be able to see the raw output of models? Or only know what the forecasters tell them? 
[In the age of powerful computers and the Internet, it is becoming much easier for users to access model outputs and make their own interpretations of the results. An analogy for this would be like patients doing their own research on the internet about their medical symptoms and what treatments should work. Independently of a doctor, a patient may self-diagnose that they have, for example, the flu… or maybe something more serious and exotic like pneumonia. They might be right, they might be wrong.]
Tom Pagano: What do you think about giving users model output? 
Norm Crawford: My inclination is to make the information available and just trust the public to read the caveats about it. That’s a better policy generally than to try to restrict the information. There’s always been in the United States [people interested in weather]. NOAA [the parent of the National Weather Service] takes advantage of an individual’s interest in those activities and will provide a rain gauge to someone [so they can measure rainfall at their house]. If [NOAA wants to] gauge in a certain area, they’ll go and find someone who would be the observer. Some of these observers traditionally were not paid. They just filled in a form every month with rainfall amounts and temperature [at their home] and mailed it in.  
There are citizen networks of automatic gauges [such as Weather Underground] that report in- there’s thousands of these stations within the U.S. were people are measuring temperature and precipitation and sometimes wind and other things. It isn’t much of a stretch for these people to acquire some software that would represent hydrology and set up their own personal forecasting system for flow in a little creek that goes by their house. That latter part, I’m not sure how much that is done but it’s a perfectly technically feasible to do.

Friday, February 21, 2014

What is a good forecast? - HEPEX Blog

Today I published my first of a series of guest columnist posts in the HEPEX blog. The topic is "What is a good forecast?" (click that link to read it). It is a non-technical discussion of what makes information trustworthy, relevant, useful and so on, in a forecasting context.

HEPEX is the Hydrologic Ensemble Prediction EXperiment, an international volunteer collective of scientists, forecasters and users interested in demonstrating the value of ensemble forecasts. This year HEPEX is celebrating its 10th anniversary. I fondly remember giving a talk in 2005 at the second workshop. It is a great effort, worthy of support!

Monday, December 16, 2013

Using balloons for flood warning

As highlighted in some previous posts about community flood warning in Nepal, it is challenging to get the attention of a community and give them actionable advice on what to do during a flood. 

Traditionally sound (e.g. from sirens) has been used for warning. However, urban sound pollution and the noise of heavy rain makes such sirens less effective. Malaysia just announced an innovative program for flood warning using balloons. 

Ahmad Phesal (second from right) with Ahmad Husaini (right) at Monday's balloon launch. (source)
KUALA LUMPUR: RESIDENTS of flood-prone Kampung Kasipillay and surrounding communities  can now act fast to take precautions, thanks to City Hall's Flood Warning Balloon.
The balloon is a project of Innovative and Creative Hybrid Group, City Hall and the Drainage and Irrigation Department (DID).
The Flood Warning Balloon, which cost RM120,000 [roughly $12,000 USD], is the first in the world, and was invented to warn residents and road users in the event of a flash flood.
When a sensor detects that the water level of Sungai Batu has risen to a dangerous level, a siren will sound and the balloon will gradually rise to a height of 50 metres in the air. It will rise to 70 metres when the water reaches a critical level.

Saturday, November 9, 2013

News aggregators- Typhoon Haiyan on Global Flood News

The major story in the news this week is "Stormaggedon" Typhoon Haiyan in the Philippines where one of the strongest Pacific Typhoons ever prompted the evacuation of hundreds of thousands and has affected millions. Some photo galleries are at Buzzfeed and the New York Times has some extended coverage. 

For an idea of the scope of the event media event though, the Global Flood News site links to over 56,000 items in the past 3 days, about 90% of which are from twitter. Their front page includes a map with counts of of recent news items related to floods. I've been watching this site for a few months and I can't remember any other stories breaking 10,000 items.    

It's possible to get information at sub-national scales, such as this zoom in to the affected region:

The website also allows you to subscribe to alerts for your area.

Monday, March 18, 2013

Spiders in the trees

Following on the earlier story about rats in New York, there is also an example of a flood's effects on spiders in Pakistan. National Geographic has a photograph and here's the original caption:

"An unexpected side effect of the 2010 flooding in parts of Sindh, Pakistan, was that millions of spiders climbed up into the trees to escape the rising flood waters; because of the scale of the flooding and the fact that the water took so long to recede, many trees became cocooned in spiderwebs. People in the area had never seen this phenomenon before, but they also reported that there were fewer mosquitoes than they would have expected, given the amount of standing water that was left. Not being bitten by mosquitoes was one small blessing for people that had lost everything in the floods."

Thursday, March 7, 2013

FEWS in the news (Indonesia)

The most widely read post on this blog is a photo essay of one of the dirtiest spots on the dirtiest rivers in the world, the Citarum River upstream of Jakarta. I also interviewed a few of the people who live along the river and those who are involved with monitoring floods before they reach the city and managing the dams upstream

 A man collects garbage washed together by Jakarta’s massive January 2013 flood (AFP Photo/Bay Ismoyo)

At the time, two years ago, there was effectively no official quantitative flood forecasting system for Jakarta, which is incredible for a city of ten million people. That has recently changed.

In January a major flood inundated large parts of the city, including unprecedented flooding of the central business district. It put a new forecasting system to the test.

Original caption: A woman stands in her food stall in the flooded business area in Jakarta January 17, 2013. Heavy monsoonal rains triggered severe flooding in large swathes of the Indonesian capital Jakarta on Thursday, with many government offices and businesses forced to closed because staff could not get to work. Weather officials warned the rains could get worse over the next few days and media reports said that thousands of people in Jakarta and its satellite cities had been forced to leave their homes because of the torrential downpours this week. REUTERS/Enny Nuraheni

From a dutch water sector news site article: "The Flood Management Information System (FMIS) that had been installed by HKV Consultants and research institute Deltares late 2012 was put to the test. The system is operated by the DKI Jakarta Public Works and connected the city’s telemetry to a flood forecasting model. The flood information is disseminated to disaster organizations. The implementation of the FMIS-system is part of a World bank flood mitigation project. The first phase was completed in December 2012."

The article also includes photos of the disaster control room.
Most remarkably, it has a screen shot of the river forecasting software.

This is quite possibly the first time that I have ever seen a time series chart of river flows and forecasts in a news article. This is also the unmistakable interface of Deltares' Delft-FEWS (Flood Early Warning System) software used operationally in the US, UK and almost 20 other countries. 

Today is actually the last day of a two week workshop to finalize the specifications for delivering a Delft-FEWS system to the Bureau of Meteorology in Australia. For the interested, I asked a Deltares representative what hydrologic model was being used in Jakarta and he replied the Sacramento model, the same as is used at the US National Weather Service. 

Better monitoring and forecasting are part of a broader flood prevention program in Jakarta. It also includes large infrastructure projects such as canals but also "soft" solutions such as improved management of garbage

Of course, Google also got in the action launching its own crisis response website for the January floods. There are also various reports from relief agencies about impacts from the flood here here and here.

Already the system is being tested again with another series of floods this week. Already 16,000 people have been affected by the March flooding (compared with 250,000 in January) although the management options are more limited because the reservoirs are now fuller than they were in January.

Wednesday, March 6, 2013

Rats! (Hurricane Sandy)

When a city floods, what happens to its rodents?

Tough as nails: New York City street rats

The AP asks "Did New York's rats relocate after Sandy?" Experts are of two minds. The city health department collects extensive surveys of rats and found that, although large storms can flush out rats, many also drown. In the end "the net effect of large storms is often a decrease in the rat population".

Some fear that the rats relocated into new territory and there has been a rise in calls to exterminators. According to a pest control expert "'They are adaptable. They can swim. They can move distances,' he said, citing radio telemetry studies showing that rats can move several miles if displaced by environmental conditions."

But this being New York, even the rats are resilient. "I have seen them dive over 70 feet (21 metres), swim 500 yards (450 metres), give me the finger and head for the hills," a rat hunting expert said, "Hurricane Sandy is not going to affect these critters."

The article mentions a serious blow to the rodent population, however- the loss of thousands of research mice in the basement of New York University's Langone Medical Center.

Original caption: In this Jan. 18, 2013 photo provided by the NYU Langone Medical Center, a researcher holds a laboratory mouse in a research building at the hospital's complex in New York. During Superstorm Sandy on Oct. 29, 2012, a storm surge flooded the basement housing some 7,000 cages of mice used for studying cancer, diabetes, brain development and other health issues. Each cage held up to five of the little rodents, and even four months later, nobody knows exactly how many perished. 

AP reports: "Now, about 50 scientists at the NYU Langone Medical Center are going through the slow process of replacing them. What they lost in a few minutes one terrible night in October will take more than a year to recover, at a cost of tens of millions of dollars."

Far from the gritty streets, these mice are kept in ultra-sterile labs and their lives are closely controlled. For some researchers it's a devastating setback. One scientist remarked about having to start over "The silver lining of the whole storm, what little there is, is the fact it allows me to refocus myself," he said. Now he can "go after what is interesting to me now, not what was interesting to me two years ago."

Monday, February 18, 2013

“I smell smoke.”

I stepped off the train at Southern Cross station in Melbourne and smelled smoke. I looked to my phone and opened EmergencyAUS (free). I started to submit a report. My options were:

“I can see”

“I can feel”

“I am”

“I can hear”

“I can smell”

I picked “smell”. I was then guided through another series of multiple choice options to describe my situation. Eventually I constructed:

“I can smell… smoke… at my current location… now.”

EmergencyAUS then showed me that a lot of other people in Melbourne smelled it too. By the looks of the map of everyone’s observations I was on the western edge of the plume; icons of noses were densest in the northern suburbs but there were reports extending straight down to the coast an hour away.


Noses in and around melbourne- other people who smelled the smoke (sorry for the terrible picture- my phone is my usual camera so this is a webcam of my phone) 

Some people didn’t just smell the smoke, they saw it. Craigieburn to the north had a cluster of icons of eyes: “I see… a plume of… smoke… at my current location… less than an hour ago…”

One of the eyes on Napier Street (3.4 km away) uploaded a photograph of a large plume of smoke that I could download. This made me realize that when I sat down at work this afternoon and looked out the window, I also saw the plume of smoke but didn’t know what I was looking at at the time.


Ordinary citizens aren’t the only ones on EmergencyAUS. The metropolitan fire brigade submitted its own blazing red icon on the map indicating “Non structure fire: going. Not yet under control- more resources requested” (upper right)

The Country Fire Authority (CFA) had its own white icon with “fire warning advice”. The advice described the situation, gave advice on what to do and included links to more information and where to get situation updates.

Earlier today EmergencyAUS pushed alerts to me that happened within 1 km of my home. For example, 6 minutes ago an alarm went off on Collins street. Earlier this weekend, I heard two sirens drive by and after checking my phone I knew where they were going. Bigger search areas are possible but the city is a busy place and I didn’t want warning fatigue.

EmergencyAUS is not just about fire. Citizens can report and learn about floods, earthquakes, tsunami and so on. They can report that they are being evacuated by the police, are without power or even are looking at a destroyed bridge (!). There is mutual community support: “I need…a generator…at my current location… now” through to “I know where to get… bottled water…”.

Who is doing this? EmergencyAUS says little about what is supporting it except to say it’s “Built by Gridstone and powered by Ripe Intelligence”. The application is free for use in one state. To subscribe to all states is $24.50, or $4.50 per state for a year.

Extra: there is another app called FireReady. While EmergencyAUS is all emergencies, FireReady focuses on bushfires and gives more detail. It too says that 30.79 km to the north 70 emergency vehicles have been attending to a large (1900 hectares) grass fire since yesterday. There are reports of wildfire on the roads and the app gives a list of what to do to stay safe. I first learned about FireReady driving by a billboard.

Tuesday, December 11, 2012

The Ultimate Forecast (the End is Near)


“My dear remaining fellow Australians…”

Late last week, Australian Prime Minister Julia Gillard spoke to her citizens, addressing their concerns about the impending end of the world on 21 December. Here is the transcript

"My dear remaining fellow Australians. The end of the world is coming. It wasn't Y-2K, it wasn't even the carbon price, it turns out that the Mayan calendar was true. While Australia's best and brightest at the [government research agency] CSIRO have not been able to confirm this, I'm confident in [local radio station] Triple J's prediction that the world is about to end. Whether the final blow comes from flesh-eating zombies, demonic hell-beasts, or from the total triumph of K-Pop [Korean pop music].

If you know one thing about me, it is this, I will always fight for you to the very end and at least this means I won't have to do Q&A again. Good luck to you all."

The predictions are based on the end of the Mayan calendar and have prompted NASA to put up a webpage reassuring people that there is no scientific evidence that the world is going to end. For example, from their Q & A section

Just as the calendar you have on your kitchen wall does not cease to exist after December 31, the Mayan calendar does not cease to exist on December 21, 2012. This date is the end of the Mayan long-count period but then -- just as your calendar begins again on January 1 -- another long-count period begins for the Mayan calendar.

On the topic that a rogue planet will strike the earth on 21 December, NASA tells us that such an Earth-killing body would have been seen by now on telescopes. 

NASA is just one opinion of many. When faced with a thorny prediction problem (including recent presidential elections), people often turn to markets for guidance. According to, some markets are stating that a Zombie Apocalypse is unlikely. Specifically

Sportsbet is running a 'novelty market' on the end of the world. While the spread of a new incurable killer virus is coming in at the shortest odds at 20-1 and being eaten alive by zombies is sitting on the longest odds at 1000-1, Sportsbet spokesman Shaun Anderson said zombies was actually the most popular bet.

The payoff on a doomsday bet is an interesting concept. Years ago I saw Al Gore give his traveling "Inconvenient Truth” lecture and at one point he made fun of a cartoon that showed a balance scale with on one side a stack of gold bars and on the other the earth. The idea was the balance and tradeoffs between conservation and economic growth. However, Gore's point was “it doesn’t matter how attractive the gold bars are, if you lose the earth you lose everything and the gold bars will be worth nothing.”

Therefore, if the Zombie Apocalypse could cause potentially infinite damage, even if the probability of it happening is extremely small, then it would always work out that the cost of protection would always be justified.

What do you think? Comment below while you still can!

Wednesday, November 28, 2012

The Last Night on the Road

It is 10:08 pm in Phnom Penh on 28 November 2012. I’m in a hotel whose name I don’t know and whose rate is $7 per night. The bar across the street advertises “no knifes, no guns, no hand grenades”. I wonder how often hand grenades are found during pat-downs.

Tomorrow I make one last visit to the Mekong River Forecasting Center before flying to Kuala Lumpur and then back to Melbourne. That will then be the end of 475 days (16 months) of traveling around the world to more than two dozen countries.

Today is the annual Water Festival (Bon Om Touk) celebrating the annual reversal of the direction of flow of the Tonlé Sap River. That bafflingly complex system deserves its own series of “hydrologic oddities” posts. During part of the year the Mekong flows North up this tributary to quadruple the size of a large inland lake. Then when the Mekong river is low, the lake drains South back towards the mainstem and to the ocean.

It seems too that tomorrow my inland lake of travel experiences will stop filling and the entire system will be momentarily still.

My bags are packed and the contents of my luggage have only gotten more impractical through time. There are a few shirts, a few pants, a fat wad of foreign currency, a cannonball’s worth of overseas coins, bags of computer cables, a stack of hard drives, medicines in five languages (none of them English) and hundreds of pages of notebooks, reports and interview notes.

This blog has only been updated through February. I underestimated the difficulty of trying to travel and write at the same time. The blog doesn’t include the visits to

Egypt: to see the world’s oldest streamgage and to see the sand dunes

Vienna: to speak at Europe’s largest meeting of Earth Scientists

France: to go to the Paris river forecasting center and to be a visiting scientist at IRSTEA, studying how to model extreme floods

Luxembourg: to go to a workshop on how to read a landscape and use that to build better computer models of its river

Scotland: to visit Mike Cranston’s group at the SEPA forecasting center and to get out into an experimental catchment in the highlands

Northern Ireland: to try (and fail) at a pilgrimage to Galway, the Mecca for hydrologists… A visit to some natural wonders would have to suffice

England: to go to the UK Flood Forecasting Centre, to talk to the developer of that country’s forecasting system, to study at ECMWF (in time to witness the landfall of Hurricane Sandy), to hobnob with the Royal Society’s elite at a forecasting uncertainty workshop

Italy: to find the source of the European Flood Awareness System (one of the most modern river forecasting systems in the world) and to give a guest lecture in a risk management course

and finally Cambodia: to shadow Australian hydrologists Terry Malone and Alex Minett during their visit to the Mekong River Commission’s Flood Forecasting Center

When passing through the Malpensa airport in Milan there was a plaque on the floor “Tuttu i passi che ho fatto nella mia vita mi hanno portato qui, ora.”

The translation is “Every step I have taken in my life has led me here, now.”

Come Friday when I land home Australia, the pause will end and the direction of flow will change.

Friday, November 9, 2012

ECMWF Awarded Noble Prize in Prediction

From a recent story in USA Today about Hurricane Sandy and the performance of the European Center for Medium Range Weather Forecasts:

AccuWeather's Mike Smith, author of Warnings: The True Story of How Science Tamed the Weather [said] "… the bottom line is that forecasters nailed this storm days ahead of its arrival. The people behind Europe's model should receive a Nobel Prize in physics, this was that powerful a moment in weather science."

There is no precedent for a meteorologist winning the true Nobel Prize (except perhaps the 2007 prize for IPCC and Al Gore).

So today I awarded the staff of ECMWF their own “Noble [sic] Prize in Prediction” for the production of exceptional Numerical Weather Predictions during Hurricane Sandy. It was my last day as a visiting scientist there.  

2012-11-09 12.40.32

The head of the research department Erland Källén (a Swede, right) graciously received the trophy (bottom center) on behalf of the employees (back).

2012-11-09 11.20.01

On behalf of the operational departments, Erik Andersson (another Swede) and David Richardson (English, but still a nice person) accepted Pop-Tart prizes (bottom) and a mélange of home made cookies (back left).

During past disasters retailers report massive sales spikes in Pop-Tarts and have taken to pre-staging them based on the forecasts:

The experts mined the [past sales] data and found that the stores would indeed need certain products - and not just the usual flashlights. "We didn't know in the past that strawberry Pop-Tarts increase in sales, like seven times their normal sales rate, ahead of a hurricane," Ms. Dillman said in a recent interview. "And the pre-hurricane top-selling item was beer." Thanks to those insights, trucks filled with toaster pastries and six-packs were soon speeding down Interstate 95 toward Wal-Marts in the path of Frances.

The monetary prize (a 5 pound itunes gift card) was donated to charity, partly to avoid the inevitable conflicts of dividing it 250 ways among the staff. Others are encouraged to donate to the Red Cross a show of support for those impacted by the national tragedy.

USA Today has a few more stories lauding the European Weather Centre’s forecasts:

Several days before Sandy came ashore in New Jersey on Monday night, forecasters were warning of a superstorm that would make a highly unusual left turn into the coastline. Anyone who didn't know a big storm was coming wasn't paying attention. This was a triumph of modern meteorology that undoubtedly saved many lives. In the era of satellites, supercomputers and instant communications, "surprise" hurricanes, such as the one that killed hundreds of people in New York and New England in 1938, are largely a thing of the past.

But before Americans get smug about their superior scientific sophistication, there is this to consider: Of the two main computer weather-forecasting models, the American and the European, the European was by far the better performer on Sandy. In the middle of last week, the British-based European model, known as the ECMWF, was already showing an unusually powerful storm moving up from the Bahamas and slamming into the mid-Atlantic coast.

Other good reads include Forecasters Absolutely Nailed This One, and Mike Smith’s own This Was Their Finest Hour (part 1 and part 2). Speaking of institutional competence…


A few days ago the Daily Show had a piece praising the effectiveness of preparations for and response to the storm.

The New York Times reports that the subways are operating again only a week after the disaster.

It has been less than two weeks since the most devastating storm in the New York City subway system’s 108-year history. Seven tunnels beneath the East River flooded. Entire platforms were submerged. Underground equipment, some of it decades old, was destroyed.

The damage was the worst that the system had ever seen. And yet, the subways have come back — quicker than almost anyone could have imagined. Less than three days after the storm hit, partial subway service was restored. Most major lines were back within a week. Repairs came so quickly in some cases that the authority was ready before Consolidated Edison had restored power.

“Some of what they’re doing borders on the edge of magic,” said Gene Russianoff, the staff lawyer for the Straphangers Campaign, a rider advocacy group that is frequently critical of the authority.

The forecasts lead to the protection of critical infrastructure and this is partly responsible for the rapid recovery compared to other disasters.


Sealing up air vents in the subway


More protections of subways



Battening boats


Removing underground electronics and pumps

Tuesday, November 6, 2012

Hurricane Sandy Photos and Recovery Stories


Closed due to the apocalypse.(Ocean City)


This aerial photo shows burned-out homes in the Breezy Point section of the Queens borough New York after a fire on Tuesday, Oct. 30, 2012. The tiny beachfront neighborhood told to evacuate before Sandy hit New York burned down as it was inundated by floodwaters, transforming a quaint corner of the Rockaways into smoke-filled debris.


Photo: The day after Hurricane Sandy struck New York City sand and muck covers a car in Coney Island in Brooklyn, Tuesday, October 30, 2012. (Charles Eckert/


Photo: A firefighter who lived in one of the approximately 100 houses destroyed by a fire that resulted from Hurricane Sandy, searches for his wifes wedding ring, in the Breezy Point section of Queens, Tuesday, October 30, 2012. (Charles Eckert/


Photo: Waves wash over a roller coaster from a Seaside Heights, N.J. amusement park that fell in the Atlantic Ocean during superstorm Sandy on Wednesday, Oct. 31, 2012. (AP Photo/Mike Groll)


Photo: Kim Johnson on Tuesday surveys the destruction around her flooded apartment in Atlantic City, New Jersey—one of several southern New Jersey coastal communities that bore the brunt of Hurricane Sandy's storm surge Monday night. Rivers of seawater gushed down city streets, swamped buildings, and destroyed a section of the city's iconic boardwalk.


hurricane-superstorm-sandy-hits-burned-homes-breezy-point_60720_600x450Photo: "We saw the glow and we couldn’t do a thing," deputy fire chief Lou Satriano told the Wall Street Journal's Metropolis blog. Satriano added that roads were also swamped and the burning homes themselves were standing in several feet of water—all of which gave the blaze time to spread. "It was a domino effect. Houses just caught and caught and caught fire."


A woman sifts through her mother's damaged home for items to save in Breezy Point, Queens.


Lost photos found.


A church cross stands amid wreckage on the coast of Long Branch, New Jersey.


A dog named Shaggy is handed from a National Guard truck to National Guard personnel in Hoboken, New Jersey.


A photograph floats just below the surface of a flooded street in Massapequa, New York.


A Virgin Mary is all that remains from a home that was destroyed in Breezy Point, Queens.


Flood protection examples: From sad


to serious.


Want to know the real way to defend yourself against floods? Read the Army Corps of Engineers flood fight handbook.


Read about the massive pumps that are de-watering New York (at Wired and Wall Street Journal)

Finally, there’s a chronicle of someone’s experience during the days of the flood:

As New York sleeps, Sandy speeds up. Morning forecasts presage an ocean-going, full-scale, "life-threatening" weather demon. Lower Manhattan's pavements clear to let it pass. In certain parts, you can cross entire blocks without encountering more than a handful of people. In case you think you've misread that last sentence, that's whole blocks. …

About half an hour later, with the wind and the rain beating against the windows, the lights go out. Via phone message, word comes of an explosion down by 14th Street. A transformer has blown as floodwaters from the East River sweep into Manhattan….

After dark on Tuesday, there are two New Yorks: the one with power and the one without any power or mobile phone signal and, in parts, without water….

Uptown, the world suddenly comes back to life. It's as if nothing has ever happened. The storm debris has been cleared away; shops are open; restaurants are serving hot food.