All of us view the world from a different perspective. Literally, each of us look at the world from a different set of eyeballs -- which by definition means -- we see a different picture. Further, each of us view the world through our respective interests, occupation, life experiences. Why do I mention this obvious observation?
Recently, I was in Nebraska on vacation or to visit family more specifically -- which was much different than California. The inevitable discussion emerged between my brother-in-law, his boss (a cattle rancher) and myself centered around the drought in California. Any time that people from other states in the U.S. (either visiting or welcoming a visitor - me) find out that I am originally from California, a discussion emerges surrounding the drought crisis in California. Often times, I learn a new fact or piece of information that I previously did not know. In this instance, I learned that a farmer's dimensional analysis of a water crisis is projected in terms of cattle (not surprisingly). Below are the details of this wonderful and informative interaction.
Cattle Consume Water?
Of course cattle drink water! That did not surprise me in the least. What did surprise me was the discussion surrounding the drought in California. Over lunch (as mentioned above) a discussion emerged that had do to with the continuous drought conditions in California. My brother-in-law's boss was grilling me about California.
Not surprising since I stuck out in the restaurant like a "sore-thumb". Why you might ask? Here is a picture of my brother-in-law and his boss below:
As we were discussing the drought in California, I decided to throw out on the table one of my newly discovered statistics about water usage in California. Which of the many do I speak of? I decided to discuss the difference in water consumption in water use -- which I wrote a blog post about a few months back. Here is the main statistic that blew my mind from Harper's shown below:
Over lunch I went ahead and gave a quick statement to invoke a response of surprise between the two residents of Los Angeles. I stated the the typical LA resident uses 107 gallons of water per day. He was not surprised at the amount. Next, I stated that the average 'Bel Air' resident uses 32,000 gallons of water per day. WOW.
What was his response?
He rapidly returned with the statement: "On a hot day, one of my cows will drink max 20 gallons of water. I guess that equals 1600 cattle then now doesn't it."
I had to stop and run the math in my head for a moment. I was amazed at his perspective. In retrospect, as a cattle rancher, this makes perfect sense. He is concerned from the standpoint of how much water is required to keep his cattle optimized. I will show the calculation below:
There are two avenues by which to verify the cattle rancher (Scott's) quick calculation. First, take both of his numbers and multiply them together. Second, divide the total number of gallons by the number of gallons per cattle to get the total number of cattle. Either way, the calculations are straightforward. You might find yourself asking the following question:
So what? Big deal -- Everyone knows that Bel Air residents are outrageous water consumers?
True. From that conversation, I took home a few pieces of information -- which I will share:
1) Each of us look at life from a different perspective. 2) Each of us have our own reference point. 3) Each of us are unique. 4) Each Bel Air reside consumes as much water as 1600 cows on a daily basis!!!!
Conclusion ...
Look, I have wrote blog posts in the past about the outrageous use of water consumers here in California. Also, I have wrote about the amount of rain in a few inches of rain fall. I have to admit that this is the first time that I have used cows as a tool for dimensional analysis. The results are staggering.
In closing, each of us have a different perspective on how to view life. Further, for a farmer in Nebraska, the mention of water usage causes him to 'default' to his cows -- which makes perfect sense. Think about the number of cattle that could be drinking next time you turn on the faucet. How many cows are you starving? Until next time, have a great day!
No dam should ever contain as much water which would put an entire city in danger of being under 65 feet of water. Unfortunately, this is the case for a city named Mosul in present day Iraq. Based on history of dams busting (one of which I wrote regarding the mining spill in Brazil), having any body of water with such a huge amount of 'potential energy' above habitats is very dangerous. I decided to verify a statistic in the blog below regarding the dam in Mosul. Let me explain.
How Large Is The Mosul Dam?
Below is a picture taken from a satellite of the Mosul dam along with the surrounding water that is contained within the reservoir.
Source: GoogleMaps
The Mosul dam is located in northern Iraq as shown on the map taken from the 'Wikipedia' page about the Mosul dam below:
According to the 'Wikipedia' page for the city of Mosul, the Tigris River is adjacent to the city (on the west bank). The population of Mosul is approximately 2.5 million people. The city is the second largest in Iraq and considered to be one of the largest northern commercial cities. Over the course of history, problems have been emerging with the wall of the Mosul dam as highlighted in the excerpt below:
The earthen embankment dam is located on top of gypsum, a soft mineral which dissolves in contact with water. Continuous maintenance is required to plug, or "grout", new leaks with a liquefied slurry of cement and other additives.[8] More than 50,000 tonnes (49,000 long tons; 55,000 short tons) of material have been injected into the dam since leaks began forming shortly after the reservoir was filled in 1986, and 24 machines currently continuously pump grout into the dam base. A September 2006 report by the United States Army Corps of Engineers noted, "In terms of internal erosion potential of the foundation, Mosul Dam is the most dangerous dam in the world." The report further outlined a worst-case scenario, in which a sudden collapse of the dam would flood Mosul under 65 feet (20 m) of water and Baghdad, a city of 7 million, to 15 feet (4.6 m), with an estimated death toll of 500,000.[9]
In an article written in 2014 on the website 'The Guardian' titled "Water Supply Key To Outcome Of Conflicts In Iraq and Syria, Experts Warn" the importance of having control over the Mosul dam cannot be overstated. If an extremist group such as ISIS were to take control over the Mosul dam, that would be strategic in controlling resources:
“It is already being used as an instrument of war by all sides. One could claim that controlling water resources in Iraq is even more important than controlling the oil refineries, especially in summer. Control of the water supply is fundamentally important. Cut it off and you create great sanitation and health crises,” he said
Isis now controls the Samarra barrage west of Baghdad on the River Tigris and areas around the giant Mosul Dam, higher up on the same river. Because much of Kurdistan depends on the dam, it is strongly defended by Kurdish peshmerga forces and is unlikely to fall without a fierce fight, says Machowski.
A 'bust' or 'break' in the dam wall would be catastrophic. The Iraqi people have been working against such a happening. Although, now, according to news sources, the situation is becoming worse. Furthermore, the threat to the city of Mosul and the surrounding area (Iraqi citizens who live outside of Mosul) who depend on the water for various purposes, should be concerned.
How much water is in the Mosul Dam?
In the excerpt taken from the 'Wikipedia' page for the Mosul dam, the estimates of a break would be a huge disaster. Nearly 500,000 people would be dead. The city of Mosul is estimated to be under 65 feet of water. Another article that was recently sent to me from the website 'Lab Equipment' confirmed the same statistic (65 feet under water) from the 2006 study. Reading this statistic, one cannot help but wonder the following question:
How much water does the Mosul dam hold?
According to 'Wikipedia' the answer is around 11,100,000,000 cubic meters -- when full. WOW. That is a large amount of water. Do you believe me (the reader -- you)? How about if the number is converted to be expressed in gallons? Lets find out through dimensional analysis. First, we should adjust that value to be more representative of the actual 'active capacity.' According the the 'Wikipedia page' for the Mosul dam above, the 'active capacity' for the dam is closer to 8,100,000,000 cubic meters -- even though the 'total capacity is 11,100,000,000 cubic meters. Below I show the conversion from units expressed in cubic meters to units expressed in gallons:
Wow! Can you imagine taking part of the job of building the dam? Must have been quite an amazing job to be part of. That amount of water is enormous. Of course, entertaining large numbers on this blog post is getting to somewhat 'routine' -- which is good. Think of the volume of water in the Brazil mining spill. The amount of water stored in the Mosul dam is 132 times the amount stored in the mine dam in Brazil. Wow! Now that we have the enormous amount of water stored in the reservoir for water and/or utility generation purposes, the next question can be asked which is the subject of the blog post:
If the Mosul dam were to break, would the amount of water stored be enough to cover the city of Mosul in 65 feet of water?
In order to answer the question, the following values need to be calculated: 1) Area (length multiplied by width) of Mosul and 2) the volume of such a rectangular box that contains the amount of water in question. I was amazed when I first heard the statistic for the following reason. The reason is simply that between the city of Mosul and the dam -- their is a distance of 35 miles.
Depending on the geography and topology, the water might go different directs rather than just accumulate downstream in the city of Mosul. Therefore, the missing (among others) piece of information in the above article describing the break and the fallout calculated by the U.S. Army Core of Engineers must include the topology of the area. The water must accumulate in the city (downstream) of Mosul in the event of a break.
With these two 'pieces' of information unknown, we can still proceed with the calculation in question by a couple of approximations. First, the geography needs to be assessed to gather the area of the city of Mosul. According to GoogleMaps, the city of Mosul is shown below:
As you can see, I took the liberty to overlay a marker through the length of the city of Mosul -- which turns out to be 11.82 miles in magnitude. The shaded area of the city can be ROUGHLY approximated to be a rectangle. That is, in order to calculate an area of rectangle, the length and width must be known. The width is shown in another picture of the city of Mosul below by GoogleMaps:
The width of the city of Mosul (according to my picture above) is 9.15 miles. With these two values in hand, there is only one value needed to figure out the volume of a rectangular box -- the height. From the article above, the height is the amount of water that the city of Mosul is proposed to be under (speculation) in the event of a dam break. That height is equal to 65 feet. The volume can be viewed below:
The rectangular coordinates given above match those from the GoogleMaps above for the city of Mosul. To determine the volume of a rectangular box, the equation for the volume is needed -- which is shown below:
In order to determine the volume, we just need to 'plug and chug'. 'Plug and chug' is a phrase used to execute the calculation by plugging in the values and being persistent (chugging) to determine the solution to the problem. In the current example, the equation is quite simple. Although, when you keep pursuing science -- sometimes the equations can get very complex. Further, sometimes so complex that a computer is needed to arrive at a solution.
Lets finish determining the volume with the values above:
With the volume of the city of Mosul determined, we can determine if the volume of water contained in the Mosul dam is enough to fill the solution (volume of city of Mosul). First, we need to convert the volume of water in the Mosul dam to a value expressed in units of 'cubic feet'. The calculation is shown below:
We can directly compare the two volumes now as shown below:
The volume of water required to fill the city of Mosul to a depth of 65 feet is only 66% of the total 'active capacity' (active volume) held in the Mosul dam. Wow! That is mind blowing. Each of the potential parameters (sewage, water, power, etc.) cited above in the 'Guardian' make sense. Especially, after performing the above calculations which cast the reported statistics into perspective. The Mosul dam is an important player in the current conflict in Iraq. The stakes are high and the fall out is extremely huge.
Conclusion
The real destruction comes as a result of the years without proper water, sewage, and the ability to desalinate the water from the Tigris River. Further, the destruction of the infrastructure as has been shown in Brazil where a massive amount of water rushes through a city or town and literally wipes out all of the infrastructure. The ability to rebuild would be diminished without proper resources, some of which are derived from the utility of having running or access to water resources.
That being said, the amount of destruction has been estimated and agreed upon by the United States of America and Iraq. Next needed is the ability to produce a solution that is viable and worth pursuing that is quick and sustainable -- two words which generally do not belong in the same sentence (quick, sustainable).
With all of the discussion surround the rain here in California and the drought, I would hope that a plan emerges in Iraq that is sustainable and attainable. Because, once the dam breaks, the water will flood Mosul and run off into the Persian Gulf. Which at that point, the water is no longer of use to the communities -- upstream or upriver from the ocean. The amount of resources needed to bring the water back into the city to rebuild would be insurmountable. The city might just languish -- pure speculation there (which equates to no value).
The amount of water involved in the discussion above is similar to other statistics seen on this blog post over the last couple of months. Lets make a change and make use of the water with the intention of writing a future post (in the form of a success of use) story with regard to its use. Until then, have a great day!
Over the course of the week here in Southern California (USA), we have been inundated with rain fall -- which the weather service attributes to a large 'oscillation' of temperature in the ocean called "El Nino." Regardless of the name of the storm, the water is much needed according to various news and State regulation agencies with all of the talk (over the last year) about 'droughts' and 'water shortages.' What struck me about all of the reporting was that I have had a new found appreciation for numbers (in inches) reported of rain fall over a given geographic region. To understand my new appreciation, I will have to go into a brief (could be a little long) back story which occurred over Christmas vacation. Of course, the results of this tangent are very relevant and might shed light on all of the reported volumes of water reported in the news regardless of the season -- drought or heavy rain fall.
Volume Of Rain Flowing Down The LA River
I start with the question: How much rain is flowing down the LA river? The reason why I chose this question in particular was due to a couple of recent news items sent to me electronically by friends. First, a friend posted a video on Facebook shown below:
Below the video in the notes the following message appeared regarding the video:
Is the California drought a scam?
"An inch of rainfall in L.A. generates 3.8 billion gallons of runoff, so you're talking about more than 12 billion gallons of water that could be captured, but that flows within hours down our concrete streets and into the ocean. There’s enough rainwater to be harvested to produce 30-50% of the entire city’s water needs."
"About half of the rainfall flowing down the Los Angeles River in a typical storm is lost to the ocean, according to the Water Augmentation Study from the Council for Watershed Health, a L.A.-based environmental organization. Most of the rainwater that bounces off roofs, parking lots, streets and sidewalks ends up in storm channels that flush rainwater into the ocean. That amounts to 10 billion gallons from an average rainstorm, enough to fill 120 Rose Bowls, said Alix Hobbs, president of Heal The Bay."
I have to admit, the video is not exactly the same video that I saw on Facebook. Still, the video appears to be very similar and to drive home the point of water just flowing out to sea. The posts on Facebook are labeled with concerns about 'wasted water.' Of course, the problem here is that the water is dirty and would need to be treated downstream and purified to be of any use to residents. With the exception of watering crops possibly (maybe).
The point is: the video above shows a massive amount of water due to just a couple of inches of rain fall. A statistic of 10 billion gallons is reported by the author above. Is this really correct? Can that much rain be falling from the sky and equate to a couple of inches of rain?
The river at its peak can move 146,000 cubic feet of water every second. At its normal rate, the Colorado River, sculptor of the Grand Canyon, doesn't do a quarter of that.
In the future, I will understand why reporters love to cite volumes in 'cubic feet.' For now, we just need to understand how many gallons/second is that equivalent to? The first calculation that I will perform (or show) will be the conversion of the 'flow rate' of 'cubic feet/second' to 'gallons/second.' I can think more clearly using units of 'gallons' rather than cubic feet. Below is the conversion:
Next, I asked myself, how long at the flow rate would the river have to flow in order to equal 10 billion gallons. Here is the calculation below:
Just over 2.5 hours -- Wow!!! That fits nicely with the values reported in the video notes. Meaning, that if water is flowing down the LA River, accumulating 10 billion gallons is not inconceivable. Not in the least. Of course, the flow rate used for the calculations is based on the 'maximum' speed recorded of the LA River in history. Regardless, the important message is that given enough time, a large amount of water flows down the river -- which would call into question the need to scare the public about droughts in California. I realize that the water is not usable directly from the river.
You might be wondering why I am thinking about the subject. I mean, aside from the recent storms that have hit Southern California over the past week and a half along with the blaring news bites about 'El Nino'. Part of the answer lies in the fact that I had large amounts of water on my mind when writing the earlier post regarding the flood in Brazil as a result of a damaged dam due to mine waste water. The other part is due to news which I received over the winter break visiting family.
How Many Gallons Of Water Equals 2 inches Of Rain?
Over winter break, we got together with family. Getting together means talking about current events. One current event was the rainfall that was hitting the Lake Tahoe region. The reason being is that my brother-in-law's family lives up near the lake. Each year, my sister and her family go and tear up the ski slopes for a few days. Therefore, their interested in storm reporting in the region.
Anyways, during a conversation regarding the weather up in the region (Lake Tahoe), I heard a number which blew my mind. I almost thought that I had a hearing issue. I asked for clarification and sure enough, I had heard correctly. The number in question was the amount (volume) of water that filled up 1.92 inches in Lake Tahoe was equivalent to 63 billion gallons.
At first, I did not believe this number to be correct. In fact, had I not previously been entertaining the number (15.9 billion gallons) which was equivalent to the mining spill in Brazil, I really would have thought my family to be insane.
After finding the tweet shown above, I just still could not wrap my head around the gigantic volume of 60 billion gallons correlating to just 1.92 inches of rain. I would believe more height to be associated with that volume. Why did the volume bother me terribly? I guess because I had not yet checked the number with a calculation of my own.
First, I think a little perspective might be needed at the moment to visualize this massive amount of water. If you have never visited Lake Tahoe, then the volume of water contained in the lake is truly unimaginable. The shoreline perimeter is 72 miles around the entire lake. One can even see the lake from space.
With the information about the LA River along with the image above, the volume reported does not seem outlandish. Although, at the time that the number of 60 billion gallons was reported to me, all of the above information had not been known to me. I had to do a small amount of research -- which is part of this post.
In fact, when we (you and I) hear or see statistics, we should not just take them at face value and believe them. A small amount of research can go a long way -- as you will see shortly. Without knowing much, how could a person check to see if the number was correct?
How can the volume be determined knowing the value of both perimeter and height?
Well, knowing the value of the perimeter in miles allows us to carry out an approximation to determine the volume. We could approximate the lake to be a circle and then figure out the volume based on an equation for a cylinder. Below, I show the approximation I made initially to do a 'rough check' of the reported number.
In the picture above, a circle is shown with a 'circumference' (as "C" equal to 72 miles -- perimeter of Lake Taho) which is equal to a factor of 2pi multiplied by a 'radius'. Since the 'circumference' is known, the 'radius' can be determined through rearranging the equation -- as shown below.
The calculated radius is expressed in units of 'miles'. In order to calculate a volume of a cylinder with height expressed in units of 'inches' then the radius must be converted from 'miles' to 'inches' as shown below:
With the radius known, the next step toward figuring out the volume of rain that correlates to the 1.92 inches of rain that was deposited into Lake Tahoe is to use the equation for the volume of a cylinder. In the same picture with the circle, there is an equation for the volume of a cylinder. A factor of pi squared multiplied by the radius and height gives the total volume of a cylinder as shown below:
The volume is expressed in 'units' of cubic inches -- which might not be useful for most people. Unless, of course, you think in terms of cubic inches or cubic feet, etc. To each his own! I am more comfortable with gallons and since the article cites water volumes in gallons -- we will stick with that unit. Therefore, below the equation for the volume, I converted the volume expressed in units of cubic inches to units of gallons using dimensional analysis.
According to my approximation using a circle, the answer (for volume) is short compared to the value reported by the news (KRON) of 63 billion gallons. Why? Ask the following questions:
1) Is the 'run-off' water from surrounding region (the mountains) the difference in volume?
2) Is the approximation of a circle that far off?
3) Is there a more accurate way to calculate the volume?
I had these questions after calculating the differences in volume. One of the most powerful advantages of having access to 'social media' is the ability to ask questions. I decided to inquire into the difference between the number I calculated and the reported number. In order to inquire into the difference, I had to find out where the number (reported number) originated.
-Transparency in reported numbers is needed
I started looking into the origination of the reported number of 63 billion gallons of water that was supposedly dumped into Lake Tahoe. What I found was very interesting. You might find the answer to be drawn out, but that is how research is done on a everyday basis. Why should investigating the source of a 'reported value' be any different? The methodology is the same as shown below.
First, I found an interesting article upon investigating further the source of the volume of 63 billion gallons of water which differed from the original value. The 'SF Gate' reported a number far less than either the original value (63 billion gallons) or our calculated value (14 billion gallons). Their value was based on a 'correction' of 6.3 billion gallons. Wow! The difference being nearly 57 billion gallons from the original value and half of our calculated value (14 billion). What is going on here?
I decided to turn to social media (Twitter) and ask KRON about the difference in values as shown below:
Shown above is the inquiry to which I have yet to receive an answer from KRON for. I decided to find out where the news organizations got the source from. After searching into the twitter accounts of both KRON and SFGate, I found that the source originated from the National Weather Service -- Reno office. Finally, I found the source on their Twitter feed shown below:
Above the tweet is another correction to the original reported value shown below:
The correction was to the value reported in "Acre-feet". I wondered if another correction would be issued for the value reported in 'gallons.' I decided to ask the NWS Reno by tweeting to them as shown below:
I included the article reporting the difference in volume -- which was significant -- below:
I waited for an answer and expected one. Not really. Although, a few news agencies are good at getting back to an inquirer quite quickly. Therefore, if you have a question, go ahead an ask someone via 'social media'. You might be surprised at the ability to get a question answered. Since the question above was to a government agency, my expectation was low.
A few days later, I was pleasantly surprised when an employee from the National Weather Service at Reno responded to my question on Twitter. Shown below is the response:
The forecaster that performed the calculation was Tim Beardsley from the NWS Reno. As indicated above, the initial value that was calculated was off by a factor of 10. Meaning, that the true number was 6.3 billion gallons of water NOT 63 billion gallons of water. Additionally, you can see that I still asked to see the equation or method that Tim used to calculate the value. I was left still unsatisfied.
Surely, I should be able to calculate the value to within the same 'order of magnitude'. At this point in time, I had to wait for another response. Keep in mind, this correspondence was occurring over the holidays. I was surprised that any responses were given. The first week in January, Tim Beardsley responded with the method that he used to calculate the volume of water into Lake Tahoe corresponding to 1.92 inches of rain fall. Shown below is his response on twitter:
After reading his response, I could see that his method was simpler. I did not realize that a value for the surface of Lake Tahoe was known. I felt rather stupid -- brain fart. Of course, use the area of the lake and then multiply that value by the height -- as shown above in the equation for the volume of a cylinder.
To verify his calculation, I repeated exactly what was reported above in the tween response. I show the results below:
As you can see, the calculation is easier than our approach. The calculation is simplified by having the 'area' -- which is equal to (pi multiplied by the radius squared).
Still, the question remains where the difference of almost double the volume comes in. I imagine that the difference is due to the calculation of the perimeter distance. Or that Lake Tahoe is not a perfect circle.
Conclusion
Regardless of the true value reported here by the news organizations, a few observations can be made in conclusion:
1) Do not take a value reported by the news as to be 'absolute truth'.
2) Different methodologies of calculating volume can give VERY different answers.
3) Different answers have VERY different meanings.
Again, no one is perfect as shown above. There were two considerations that were not discussed in the blog post among others (I am always open to suggestions). The first was that in the corrected twitter post by the NWS Reno, the value of 'acre-feet' was off by an order of magnitude. A large difference exists between 196,100 acre-feet and 19,600 acre-feet. How large? Exactly 176,500 acre-feet. How did that difference arise during the calculation?
The second consideration was that there exist a second method by which to calculate the total volume of rain fall by hydrologists. According to the explanation above from the NWS Reno, a 'Rating Table' is used by hydrologists (click here). Regardless, a greater degree should be a goal of the National Weather Service in Reno regarding the method of calculating weather conditions.
A few readers might not agree with the last statement regarding organizations being more transparent with their methodologies. Ask yourself the following question:
How many times have you looked out the window after looking at the weather forecast and said "Wow, the weather channel really got that wrong?" "I wonder how the weather channel came to this conclusion?" This should warrant a greater degree of transparency -- for those interested in understanding the methodologies used.
As I have shown above, the amount of rainfall that drops on Southern California is quite large. Not just quite large, but HUGE. Scientists and engineers should be trying to come up with methods to capture this water for alternative methods. Or at least building 'floatable turbines' or another method to turn the mechanical energy (the energy of flow of water) into electrical energy. What do you think? How would you harness that power? Until next time, enjoy pondering the numbers reported in the post. Have a great evening.
Last Sunday, the Los Angeles Times ran a piece on a recent 'environmental disaster' in Brazil that has been unfolding over the last month. The title of the article was "As Brazil Mine Spill Reaches Ocean, Its Catastrophic Extent Becomes Clear." I was reading the article in a hurry and did not really get a chance to digest the entire piece. What I mean is -- upon reading the article a second time through, I found myself astounded. In between the first and the second reading, I realized that the reported values fit perfectly into the theme of blog posts on this site.
As I mentioned above, between the two readings a couple of events transpired. I think honesty is a good practice -- to admit that I am not perfect. After I read the article the first time in a rush, I e-mailed the author and asked him for more information. Specifically, the first paragraph states the overall 'eye-catching' general consequences of the disaster:
Since millions of gallons of mining waste burst from an inland iron ore mine a month ago, 300 miles of the Rio Doce stretching to the Atlantic Ocean has turned a Martian shade of bright orange, and the deadly consequences for residents and wildlife are just beginning to emerge.
I posted a question on the author's twitter account to inquire into a more definitive quantity of waste water that was actually spilled in the disaster. He responded by informing me that a more accurate estimate of the total volume was listed in the article. I quickly read the article for the second time, looking for a volume listed. This is what I found:
The dam near the inland city of Mariana that broke on Nov. 5 is operated by Samarco, a mining company owned by Brazilian mining giant Vale and Anglo-Australian mining giant BHP Billiton.
When the barrier burst, for unknown reasons, more than 60 million cubic meters of waste began flooding nearby communities and wound up in the Rio Doce.
Without talking about the long-term environmental effects (which will be covered in a later post), I wanted to focus on the magnitude of waste released from the damaged dam. After exchanging correspondence with the author, I was looking for a reported/stated value of waste water expressed in 'units' of 'gallons' rather than 'cubic meters.'
Whenever you express a value, the importance of keeping uniformity (in reporting units of measurement) cannot be understated. This is to avoid confusion. In the situation described above, I was expecting to find a total volume of the mine spill expressed in units of 'gallons' rather than 'cubic meters.' Regardless, the value was expected to be large based on the picture in the article -- which are shown below:
Source: LA Times -- Brazil's Rio Doce River
My curiosity started to run wild. I could not get my head around the reported value of 60 million cubic meters. What was the equivalent volume (60 million cubic meters) expressed in gallons? Therefore, I decided to calculate the value in gallons using dimensional analysis. Below is the the conversion based on the conversion factor of cubic meters to gallons (1 cubic meter = 264.172 gallons).
In the first line, the value of 60 million cubic meters is expressed in scientific notation. The use of scientific notation allows large numbers -- extremely large numbers -- to be expressed more easily. Regardless of notation, the number of gallons is HUGE. The extent of the disaster is INSANE. After I saw the number of gallons, I immediately started wondering how the number (15.9 billion gallons) compares to various volumes. What volume would be sufficient to compare to the present 'man-made' disaster?
How many 'Deepwater Horizon Oil Spills' would compare to Brazil's mine spill?
Since the topic was a man-made environmental disaster, I immediately thought of the tragic 'Deepwater Horizon Oil Spill' back in 2010. The oil flowed out of the well for 87 days and amounted to a total of around 210 million gallons. That is why I was extremely surprised by the reported volume in the 'Times' article about the Mine Spill in Brazil. I decided to compare the two volumes.
Specifically, I wanted to know how many oil spills would be equivalent to 15.9 billion gallons of iron-ore waste. First, I converted the value of the spill into scientific notation. Then I divided the two volumes to obtain the number of equivalent oil spills. Below are the results:
Wow! Unbelievable. I am blown away. I cannot believe that the equivalent volume of the Mine Spill is comparable to 78 Deepwater Horizon Oil Spills. That is a LARGE amount of waste water (iron-ore waste). The volume was so large that I was still having trouble wrapping my head around the magnitude of the volume.
As a result, I had to find another image to assist my inability to wrap my head around the value. I found a photo from an article in the Wall Street Journal titled "Samarco May Not Shield BHP, Vale From Brazil Dam-Breach Repercussions."
The volume of iron-ore waste started to make sense after viewing the above photo. Based on the photo above, that large volume would have destroyed a large area of land -- such as that above. As the picture portrays, the water must have thrashed the town houses, cars, and forestry in the path as the potential energy of the stored water (in the dam) rushed out. Again, that damage must have been due to a large amount of water -- like 15.9 billion gallons. WOW.
Still left rather unsatisfied. I am having trouble visualizing 78 'Deepwater Horizon Oil Spills.' In light of this feeling, I decided to compare the value of 15.9 billion gallons to a couple other volumes: 1) the Mercedes-Benz Superdome and 2) the world's largest pool. These two volumes are extraordinary feats of construction. Further, the two volumes have served me well in past posts using dimensional analysis.
To start with the Mercedez-Benz Superdome in Louisianna. The volume reported on the 'Wikipedia' site of the interior of the Superdome is believed to be around 3,500,000 cubic meters. Below is a picture of the Superdome:
How many of these Super structures will be required to hold a volume of 15.9 billion gallons? Below are the results:
Again, the number is large -- HUGE -- beyond comprehension. The last remaining super structure that is appropriate to compare such a volume is the World's Largest Pool. The World's Largest Pool is located in Chile and is shown below:
This amazing swimming pool holds an astounding 60 million gallons of water. That is enormous. Although, based on the mentioned volumes above, the volume of the World's Largest Swimming pool is starting to look rather small. To be complete, the calculation was carried out. Here are the results:
Oh my goodness, 265 swimming pools would be required to hold 15.9 billion gallons of water. This should be too surprising. Imagine what your guess would have been at the beginning of the blog post after hearing the initial value that was reported of 60 million cubic meters? Would your guess have been larger, smaller, or equivalent to the calculated value?
Conclusion:
As I mentioned in the introductory blog post for this website, my intention was to demystify numbers that were reported in the popular news. Further, to give the reader or you a better understanding how how a scientist thinks. These objects, structures, or volumes were what came to mind while reading the above articles.
Does that last sentence sound crazy?
If so, relax, and do not stress yourself out. The world is full of diverse people. I might not think like you. Furthermore, what questions arise in my mind might be completely different than those that arise in yours -- even after reading the same article.
Who cares about the value reported?
That is another story completely (and another blog post). We might have different interests, concerns, questions when reading content in the popular news. What unites us in this situation is that we both live on the planet Earth. If these tragic accidents keep occurring, the toll down the line (in years to come) could be deadly to everyone (not just the Brazilians).
The first step toward being concerned about possible issues (some of which I will bring up in the 'follow up' post on this disaster) is the understanding of the magnitude of the problem. As I mentioned, the first time that I read through the article, I missed the HUGE magnitude of the disaster (volume of waste) due to different units. This shows how narrow-minded I was -- I am looking for gallons. I should have slowed down and read the article more carefully the first time around. How often do you have the same happen to you? Reading too quickly to miss the content? These are questions that each of us need to answer based on our own actions.
I hope that the disaster down in Brazil has been brought into a different light for you after reading this post. Have a great day!
