Guest Essay by Kip Hansen
Last January, I wrote about the curious case of Lago Enriquillo in the Dominican Republic, the “Dead Sea of the DR” – a super-saline lake that lies about 140 feet below sea level in the east of the country right up against the border with Haiti. The lake has been growing since 2003, flooding local villages and overwhelming local agriculture.
In my previous essay, I discussed the possible causes of the growth of the lake and dismissed the silly idea, put forth by the New York Times’ Randal Archibold, that the cause was their one-note bogeyman, global climate change. The major cause of flooding in this part of the country is the long-term deforestation – the image above shows the flood areas (in red) down in the valleys – when the tropical storms come and bring inches of rain per day, it all runs down the rugged, denuded hills into the streambeds, into the rivers and eventually into the sea at Barahona. The major “cuenca” – Dominican for watershed – of the region is the Yaque Sur. The map below shows the current flooding of Lago Enriquillo
My wife and I spent many years in the DR and for a while focused our efforts in the rocky valley – a gorge really – formed by Rio Las Cuevas (in the red box on the map), where we represented a humanitarian organization that funded a series of irrigation projects in the villages there in partnership with a local organization – Sur Futuro. All projects included an element of reforesting the hills with native trees or a permaculture mix of native trees and commercially valuable fruits and bushes (such as coffee), under-storied with subsistence vegetables.
It is a truly awesome sight to see these small dry valleys, with tame little rivers or even small creeks running down them, turn into raging maelstroms of churning water and stone such as happened with Hurricane Noel in 2007. There had been a lovely little horse ranch on an island in the rocky dry riverbed of the Yaque Sur, a green oasis amidst the sea of grey stone – a house, barns, corrals and pastures. After Noel, the entire island was simply gone. We could not get up the Rio Las Cuevas valley for almost six weeks.
The direct cause of these massive floods, with almost flash-flood intensity, is the historic deforestation of the surrounding mountains. The cure is reforestation – a cure that will take generations.
In my essay last year, I posited that the underlying cause for the rising water in Lago Enriquillo was this very deforestation which, despite some protests to the contrary, is ongoing and continuing due to the increasing population of the area brought about by the increase in successful agriculture and their never-ending demand for wood to use for cooking fuel. This rather offhand assertion lacked a certain finesse and did not answer all the variables involved in a more complex problem — I offered it in good faith mostly to offset the ridiculous idea that Global Climate Change was to blame.
I am a real fan of actual discussion in the Comment Section – to me, this is where the understanding comes about. Not just for the readers, but for the authors – hopefully – as well. As the discussion evolved, it struck me that the areas north and east of Barahona had blossomed in the previous ten years or so due to irrigation water supplied to agriculture from the upper Yaque and the large dam near Padre Las Casas. This water was supplied the old fashioned way – in irrigation canals.
Yes, you see, connect the dots – increasing population around Lago Enriquillo due to increased agriculture – agriculture made possible by irrigation, water brought in by ditches – from – you guessed, the Yaque Sur dam.
Digging more than a little bit reveals that INDHRI – the Dominican Water Resources Institute – had been running water from the Yaque Sur watershed into the Enriquillo watershed from which there is no outlet.
Those of you with quick minds can already sense the situation. Hold on to that thought.
After many days, I went on to some other project. Revisiting the essay last month, I discovered that a reader “J. Gonzalez” had left a critical comment . Here’s the gist of his complaint:
– “INDRHI believes the problem was the broken dyke at the Yaqui del Sur, which allowed fresh water to rush into the lake, causing the levels to rise and also the salinity to drop. …. There are many, many connections between the Yaque del Sur and the lake.”
– “But then canals from the Yaque del Sur were constructed to keep water levels steady and the salinity at such a rate that marine life could continue to survive. But the lake surface area never expanded at the rate it did after one of the Yaque del Sur dykes broke following the storms in 2003 — Claudette, Odette, etc.”
– “The Army Corps of Engineers and a group of scientists from NY came here to study the lake and said the cause was inconclusive, but likely due to increased rainfall and the broken dyke. Whether the increased rainfall is due to climate change is up for dispute. In my opinion, it seems unlikely, especially in that time span.”
The purpose of this essay is to expand on my original investigation as to the causes of the ever-expanding lake. (Note that the lake did not seem to continue to grow in the year 2013 according to the press in the DR – I have not found any information about 2014.) I appreciate J. Gonzalez’s comment as it spurred me to deeper investigation.
There have been quite a few in depth studies of Lago Enriquillo:
As I pasted this in, I realized that it is in Spanish. I’ll have to use it as is, with a bit on on-the-fly translation. [Over 13% of Americans speak Spanish as a first language in their homes – even more speak Spanish as well as English. In Florida, there are Walmart stores in which all the signage is in Spanish.] The chart shows the seven most important studies done in recent years with a summary of their findings on causes and solutions.
As for Sr. Gonzalez’s first point “INDRHI believes the problem was the broken dyke at the Yaqui del Sur, which allowed fresh water to rush into the lake” – I could find no mention in any of the studies or in the Dominican printed news media, or on the INDHRI website, which would indicate that INDHRI (or anyone else) believed that a broken dyke had “allowed fresh water to rush into the lake”. One of the studies in the chart – CIBIMA-UASD (2011) – found damaged infrastructure or faults in irrigation canals – might be a contributing factors, along with seismic activity, erosion and sedimentation, and correlation between Lake Sumatre (in Haiti) and Lago Enriquillo. The study in which the Army Corp of engineers participated did not mention a broken dyke incident. More about “canals” is our next point:
Sr. Gonzalez’s second point is: “But then canals from the Yaque del Sur were constructed to keep water levels steady and the salinity at such a rate that marine life could continue to survive. But the lake surface area never expanded at the rate it did after one of the Yaque del Sur dykes broke following the storms in 2003”. Again, nothing in the seven reports or the DR news media supports the assertion that some one broken dyke was or is responsible. Many of the reports speak of the poorly built and poorly maintained irrigation canals as a possible problem – the canals “leak” water into the surrounding soil. One of the reports reported in the media was on a study that used satellite data to “see” subterranean water flows and reported that there were subterranean streams and flows into the lake from all parts of the watershed, which is exactly what one would suspect for a below-sea-level lake.
[The datum marked “unlikely” is over ten meters higher than the expected range…such an increase would have been extraordinary and had it actually been true, would certainly be mentioned in narratives about the current rising water levels, which it is not. There is no mention of such levels occurring in the mid-1960s.]
Note that Sr. Gonzalez mentions the fact that canals were intentionally used to bring fresh water from the Yaque Sur watershed into Lago Enriquillo to replenish the shrinking lake – and ever more saline lake – in 2003….in other words, bringing water from the Yaque watershed into the Enriquillo watershed was a solution…and one that I think has had unintended consequences. Prior to 2003, there was national and international concern that Lago Enriquillo was shrinking, and becoming more saline, threatening the native fishermen’s livelihoods and the endangered salt water crocodiles that live in the lake. A scheme was carried out to bring water from the Yaque Sur to Lago Enriquillo, via canals, based on the long-term shrinking trend from about 1965.
Let’s look at the watersheds:
The first image is the official INDRHI map, showing both the YaqueSur and the Enriquillo watersheds, accompanied by a satellite photo with cross-hatching (sorry, it’s a bit dark), and my road-map overlaid with some elevation numbers at critical points and a big red line approximating the divide between watersheds.
This greatly magnified topographical map clearly shows the canals leading to the lake. Even more canals were built since the 1990s to bring irrigation water to the vast fields of bananas and avocado groves. All the water is brought in from the Yaque Sur watershed. Every drop of water brought into the Enriquillo watershed that does not evaporate or get exported as moisture in agricultural products, ends up in the lake. There is no other exit.
What other possibilities are there? The seven studies list the following as possible suspects:
1. The plain-jane theory: ingress of water (rain water) above the soil’s retaining capacity, resulting on more water into the lake. 5 of 7 studies mention this.
2. Increasing rain due to increased evaporation from warming oceans – somehow coupled to reduced evaporation from the lake.
3. Increased rainfall resulting in increased freshwater input from springs. See #1.
4. Deforestation resulting in more runoff coupled with increasing sedimentation due to erosion caused by deforestation.
5. Ingress of irrigation water to the watershed – excess of irrigation.
6. Five hurricanes and tropical storms in the 2007-2008 period.
7. Seismic activity which may have either opened up more freshwater springs or opened a connection allowing water to drain from Lake Sumatre in Haiti into Lago Enriquillo.
A summary report supported by the European sources, by Reynaldo Payano and Ojilve Medrano, concludes: “The increased water level of Lake Enriquillo is probably due to an increasing number of events of high precipitation during the past few years higher than the capacity of the soil and groundwater inputs of the Etang de Saumâtre Lake (Lake Sumatre).” And recommends more study. (The chart of seven studies is from their report). Please note however that none of the reports contains actual annual local precipitation numbers.
So, here is my conclusion:
1. There is more water coming in than going out (via evaporation). See 2 thru 5 below.
2. Increased rainfall,
3. coupled with increased deforestation which reduces the capacity of the soil to absorb and retain water
4. coupled with increased sedimentation of the lake during heavy, tropical-storm and hurricane rainfall events, caused by erosion which is caused by continuing deforestation, which results in raised water levels.
5. Uncontrolled and unregulated ingress of water from the Yaque Sur watershed by way of canals – like leaving the water running, even if “just a little”, into a stoppered bathtub.
Why don’t I list water running in from Lake Sumatre? This graph show clearly that the water level in Sumatre increases along with that of Lago Enriquillo…if it was truly water from Sumatre “leaking” into Enriquillo, it seems to me that Sumatre would either shrink or remain level while Enriquillo rises. I am, however, no hydrological expert.
What lesson can we learn from all this?
We can learn that climatic issues are very complicated and simply blaming any and all situations on Global Climate Change just because they have a factor that is related to the weather is almost always wrong.
Scientists can work very hard on an issue, study the various aspects of a problem with heavy-duty statistical packages, satellite imaging and image parsing software, ground piercing radar, and other sophisticated tools, and still, different groups of scientists, studying the same problem, can come up with different results and conclusions. Seldom does one study resolve difficult issues. Sometimes even many studies do not resolve an issue, as we find here.
Sometimes an unsupportable “scientific idea” – a proposed cause of a problem – gets injected into the popular culture of the locale involved – such as the “broken dyke” theory (which did show up in political attack Opinion Section columns in the DR – but was never mentioned in any news reports or scientific studies) – and then remain as part of the popular culture, despite study after study which finds the cause to be nonexistent or not true.
In the case of Lago Enriquillo, in spite of the relationship between lake levels and incoming water, none of the major studies actually attempted to measure, or even estimate, in any way, the water being imported into Cuenca Enriquillo from the Yaque Sur – even though they were attempting to understand where the extra water was coming from. This strikes me as an obvious oversight – or political correctness, not wishing to blame a government agency [INDRHI] for causing the problem.
It will be interesting to see how the lake fares over the next couple of years. I’ll try to write an update next year.
# # # # #
Author’s Comment Reply Policy: This essay is not about AGW or Climate Change or the Climate Wars, so let’s not have comments about those topics.
Salt-water crocs, however, may be appropriate.
I prefer civil conversation.
I have links to all the studies, most of which are in Spanish, for those who want them.
First impressions, it looks like this location is in a geological strike-slip fault zone – like The Dead Sea.
Reply to Jimmy Haigh ==> One can see clearly in the satellite image with the red rectangle (near the top of the essay) that when the sea level was appreciably higher, maybe only 50 feet or so, Lago Enriquillo would have been a “deep place” in the channel between an island (maybe two) and the mainland.
There is a major fault underlying the lakes — this image shows the fault lines. One of the faults shown caused the devastating earthquake that mostly destroyed Haiti’s capital city, Port-Au-Prince.
“it looks like this location is in a geological strike-slip fault zone”
It is – it lies right on the border between the North American and the Caribbean continental plates.
Absolutely everything is blamed on ‘global warming’ including all cold weather related conditions. Proving this wrong is unnecessary, they have to prove their case to us, not the reverse.
All below sea level situations in geology means hotter climate conditions locally and very saline conditions of water and either becomes an inland sea or dries up (Death Valley being the example of drying up).
“All below sea level situations in geology means hotter climate…” Indeed. It should also mean that scientists realise that this is the reason our average surface temperatures are warmer than those of the moon. Not “greenhouse gasses”. See Nikolov and Zeller November 2011.
This is not all that different from the circumstances that caused the Great Salt Lake to suddenly grow in the early 1980s. The growth occurred during a period of heavy runoff from unusually snowy winters. The lake destroyed the renovated Salt Air Resort and threatened the railroad causeway and the airport. Doesn’t the nature of random events suggest that precipitation will exceed evaporation at times, and cause water bodies lacking an outlet to grow?
Climate change is the lazy explanation.
Reply to Kevin Kilty ==> The chaotic nature of the Earth’s climate system dictates that in a closed system such as Lago Enriquillo, the balance between water-in/evaporation-out will be out of kilter virtually always. One can’t predict which way and for how long. 1965-2003 mostly shrinking. Before 1965, rising. Since 2003, rising rapidly. 2013, level….etc.
Adding in the extra element of bring in irrigation water, directly into the lake, or just into the watershed, has upset whatever balance would exist if left alone.
Out of kilter also is descriptive of what’s going on at Devil’s Lake in North Dakota. Climate is sometimes thought of as average weather. I think people lose sight of the unevenness behind the averages. Lago Enriquillo, the Great Salt Lake, and Devils Lake all illustrate the unevenness.
Reply to HankHenry ==> Yes, Devil’s Lake is a perfect example of the same thing happening elsewhere. The people there, despite evidence that the lake had been historically much higher in the past, settled, built cities, and developed fields for crops on land that they should have known would be submerged again when Nature brought the lake back up.
Those interested in this USA version of a closed watershed lake can see Devil’s Lake Quick Facts.
Add this as case number two of noted use of climate change to ignore deforestation and its effects. Case one was the UN report on deforestation that underestimated it and received push back from those who knew better with satellite data in hand. One consequence of all hands on deck with climate jihad and climate witch hunts is that it does take a lot of eye balls off important facts on the ground. Memo to UN and NYT, the Ebola crisis was similarly the result of eye balls not doing their job while others saw it coming.
Reply to Resourceguy ==> An important thing to realize about the DR is that Europeans first arrived in 1500, over five hundred years ago. The rural poor there live much like their ancestors did four hundred years ago — they have basic shelter, outdoor toilets, no window glass, no screens, no refrigerators, and cook mostly with wood or charcoal. The constant, incessant need for cooking fuel leads to almost total deforestation everywhere there are people. adding to this — the DR has native mahogany — very valuable — and although protected by law, it continues to be cut and sold driving it to near local extinction.
As Plant and Soil Scientist I wonder where are the necessary water budget figures? I would also comment that the rifting situation there means that stability cannot be expected. Brett
Reply to Brett Keane ==> The best two sources for water budget and water balance on this issue are:
MAPA GEOLÓGICO DE LA REPÚBLICA DOMINICANA (en español)
http://mapas.igme.es/sgn/docu/memoria%20geologica%205971-iii%20neiba.pdf
Water Level Fluctuations of Lake Enriquillo and Lake Saumatre in Response to Environmental Changes
(in English)
https://dspace.library.cornell.edu/bitstream/1813/23555/2/MENGReport-Poteau-RomeroLuna.pdf
When chasing down a will o the wisp it’s often very helpful to nail down the specifics. What was the name of the dyke that broke? Where was it? What’s the physical method that caused the resulting lake enlargement?
In the US, dumping flood waters across a state border is one of those big no nos that most people don’t think about. There was a theory that my town (which is a border town along the Illinois/Indiana border) was flooded due to just such a water dump from Chicago. It was educational chasing down that theory and finding out it was not accurate. The key was pressing for more information, more details, until it became clear that the theory didn’t conform to reality.
Great work Kip, a home run of facts that will be ignored by the UN and NYT and of course Obama.
Regarding Lake Sumatre, if increased rainfall/runoff is a major cause then I’d expect both lakes to rise even if there is some flow from Sumatre.
Deforestation I would expect to have an effect too, in mid-Wales in the 50s the native deciduous woodland on the hills was replaced by commercial conifer forest. In the 60s unusual heavy flooding occurred in the downstream catchment areas. It was found that the rainfall ran off faster in the new situation causing faster water level rise. They ended up building flood control reservoirs to deal with it (Llyn Clywedog). http://en.wikipedia.org/wiki/Clywedog_Reservoir
Reply to Phil ==> Yes, they would rise in unison, but then because the rainfall is very episodic (nearly 100% of the precipitation falling in huricane season, and often in just one or two storms), one should see a lowering of the water level in Sumatre as it leaks into Enriquillo if the effect it real and substantive over the next ten months — the level in Sumatre would have wiggles in it — which don’t show.
Thus, I leave it out in my personal suspect list.
The dam on the Rio Yaque Sur (in one of the maps up in the upper right near Padre Las Casas, is the flood control effort for the Yaque Sur watershed. Things were much worse before it was built.
It would help if Lago Enriquillo was actually labeled on either of the first two maps.
Reply to Louis ==> Sorry. Don’t know what I was thinking — I had to look at the first few maps above to see if they didn’t label Enriquillo (they don’t).
No problem. I did a search and saw that right next to the lake was Los Rios, which appears on map 2. The reason I prefer to be spoon fed is because it saves time.
Interesting article but the most interesting part is the observation that “broken dikes” can never be fixed even after they are proved to not have happened. There are many other such examples: DDT and eggshells, Ionizing radiation at any level (including those well below “natural” background radiation) PCPs and Ozone to name a few.
They become truisms that “everybody knows” without regard to the actual science involved and before long one has well to do, educated people refusing to have their children inoculated from devastating diseases because they have adopted a mythological “belief system” rather than mastered critical thinking.
Thanks for posting a thoughtful and illuminating article.
DR is a major source of charcoal for Haiti. All totally illegal of course, all managed by a charcoal mafia. Deforestation is a the inevitable result. It makes a lot of money for those involved.
Planting trees is great. Just plant also the idea that managed forests are the long term future.
On another thread I did a back-of-the-envelope calculation that suggested you could support a population density of 60 per square mile harvesting wood from managed wood lots for home heating, to the tune of 3.5 cords of wood per year. The DR has a population density of 492 per square mile. I don’t know how wood usage scales for cooking-only vs heating in Oklahoma, but that would be the key as to whether managed forests are a true solution.
How would coal work? I see prices on line quoted as low as $38 per ton spot price. Per capita GDP is around $9,700 per annum. How much coal would you need per year to cook your food?
Reply to D.J. Hawkins ==> The best solution ecologically for the DR is to cook with propane or natural gas — but only the generally well off can afford to do so reliably. Except for the profoundly poor, most homes have a propane cooker of some type. But propane costs cash money and when cash is short the gas bottle stays empty and the wood cookstove (often like the old American brick outdoor BBQ) is fired up using whatever wood can be found or bought. Charcoal is often for sale on the streets, even in Santo Domingo — native charcoal made in the hills and brought down in rickety wagons or old mini-pickups.
The DR has no source of natural gas. The CIA Factbook lists DR –> Natural gas – production: 0 cu m (2011 est.). All natural gas is imported by tanker ship. There are two large clean-coal power plants under construction there, but I don’t know where the coal will come from, but it is not from the DR.
I understand that coal is not an indigenous resource, but is it cheaper, even if imported, than propane? If the poor are using charcoal, presumably it isn’t 100% home made; how do they pay the charcoal burner?
Reply to Hawkins ==> Native charcoal is cheaper than propane and is an easy product to use, as all Americans of my generation know — it makes a nice clean, hot fire, and just a few coal are needed for simple cooking. Charcoal burners in the DR are rural peasants who burn charcoal as a sideline — they make a nice profit but sell charcoal very cheap — the materials — poached wood — cost them nothing.
If the Dominican poor were using what we think of as a wood fired kitchen stove, coal would be a better solution. However, they aren’t using a real kitchen stove, they just build a little fire in a fire pit, sometimes as sophisticated as an outdoor brick bbq from the 1950s, but usually just a few concrete building blocks forming a “U” with or without a grill across the top. Even the well-off have a little fire pit out back to use when the gas runs out. They build a stick fire and only keep it burning as long as they need to cook the meal, then let it go out. Coal does not lend itself easily to this method of cooking, at least in my experience.
The country will be importing a lot of coal for the power plants. A substantial portion of that coal will “fall off the truck” and end up for sale on the street…so we may yet see coal supplanting wood at least in the areas near the new coal fired power plants.
Kip, While reforestation, and local ownership of those forests seems very desirable, maybe some kind of fuel-efficient firewood/charcoal burner would also have an impact.
Reblogged this on CraigM350 and commented:
A thoughtful read. As the author suggests sometimes a confluence of events may be the cause, some us, some completely outside of our control.
Reply to CraigM350 ==> Thank you. Yes, real useful answers are often difficult to find and often point to things outside the control of Man.
Reply to Crispin ==> The interesting thing with the projects we were involved in is that the reforestation portions always came with a lot of indoctrination/training. The local project beneficiaries actually planted all the trees themselves as part of the deal to receive the materials and engineering help to build irrigation systems for their fields.
This aspect makes the renewing forest “theirs” , not belonging to someone else – the idea builds ownership and local pride. Their children will experience the real benefit of 10,000 new trees on their mountain.
“…a super-saline lake that lies about 140 feet below sea level in the east of the country right up against the border with Haiti.”
That’s the -west- of the country as far as I can see.
Reply to The Old Crusader ==> Happy Fingers Day! (That’s the day that my fingers type what they want, and not what I tell them.)
It is amusing that a dozen editing read-throughs fails to find such egregious errors. The West of the DR, the East of Haiti.
Moderator — If a moment, could you save me further embarrassment by making that little (?) correction, substituting west for the erroneous east? Thanks…kh
Not so little Kip I also flipped back and forth and with the missing names I almost left the story but thankfully I stayed on, read it and learned some more, so don’t sweat it, good research!
Thank you for your article.
If the current lake level is several metres below the 1975 level, is the recent rise a problem because people built or farmed on the land previously covered by water?
There are several instances in Australia (the recent Brisbane floods being the most dramatic) where the folly of building on flood plains has been realised.
Reply to John in Oz ==> Yes, of course. There are no such things as building codes or laws that prevent people from building on historic flood plains — which, in the short-sighted view of the profoundly poor, present an opportunity to posses land that one else already owns.
There are whole neighborhoods built in Santo Domingo on flood plains that flood at least every five years, sweeping away the residents homes and possessions.
In the 1980’s my family helped clean mud out of homes in New Jersey, USA which had been built on a known 100 year flood plain.
This tendency was known in Biblical times resulting in the admonition not to build your home on the sand, “like a foolish man who built his house on the sand,” instead of up on firmer, higher ground.
You talk of changes n precipitation but how misty or foggy is it there?
Evaporation will be greater from a clear sky than a fog-bound lake.
Question, has the deforestation caused a change in humidity and thus fog in the area.
I confess that my experience in England may not be applicable in the Caribbean
Reply to MCourtney ==> This area of the DR has the same climate type as Arizona — dry, sandy and rocky soil, scrubby brush and cactus. I have never seen fog in the area, though no reason for it not to be possible.
If you look at the second map in the essay, you’ll see that the lake lies in a low narrow valley between the Caribbean Sea (at Barahona, where I can recommend an excellent hotel) and Port-au-Prince Bay (at the Haiti end). The nearly endless trade winds blow east-to-west (I have that right this time) right through this valley, in one end and out the other.
Well, the wind would prevent fog over the lake (not over the land)… unless the wind was blocked by forestation.
Were you able to get hold of the Buck et al paper to see where they went wrong on Hurricane Cleo? –AGF
reply to agfosterjr ==> I have this:
Physical and chemical properties of hypersaline Lago Enriquillo, Dominican Republic
David G. Buck, Mark Brenner, David A. Hodell, Jason H. Curtis, Jonathan B. Martin and Mark Pagani
Jan 2005
Doesn’t seem to be the paper you are talking about.
Give me another clue —
Yeah, that’s the one. So how did they get so far off on the 1965 lake level? 15m is hard to lose. I don’t believe the evaporation rate shown on the graph is possible. –AGF
I see I sent an email to Roberto Cruz a year ago but he never responded. –AGF
Thanks, Kip. After a preliminary look at your data, I can see a pattern noticed elsewhere. As the Pacific moved towards a cooler phase earlier this century, it caused tropical and sub-tropical seasonal rainbands to move north. Our navy (RNZN) was sent to supply water-makers to islands either side of the line because of this (maybe!). Anyway, the shift affected other places too, and less rain someplace tends to mean more elsewhere. At the time, I think I also saw a northward shift of southern polar and temperate zones, using my University data access. Since then, I have been searching for mechanisms. These blogs are helpful.
It feels great to get back into the ‘deep waters’ of soils and plants. At first and second glance, the Cornell thesis seems to have merit. Brett
Error: southern polar and temperate convergence zones, Brett
Reply to Brett Keane ==> Glad you are enjoying this mini-series on Lago Enriquillo.
The Cornell study by Eva Joelisa Romero Luna and Dina Poteau (August 2011) unfortunately calculates the water balance of the Enriquillo watershed, entirely neglecting the inputs of millions and millions of gallons of irrigation water imported from the Yaque Sur watershed via canals — canals of poor physical quality that leak water where not intended, and that deliver water, more or less unregulated, to plantations of bananas and groves of avocados.
Not accounting for the imported water, in my opinion, is a serious error, and may invalidate their findings altogether.
Certainly the lake grows and shrinks in normal circumstances in line with major precipitation events. Having a constant additional input since 2003 unaccounted for may kick things over the top — the date coincidence is striking.
I suppose we can come to no conclusion, if we do not know the volume of the increased lake waters over time, to start with. After that, attempts at attribution could start. Dry-season irrigation may have less effect than the rainy seasons, but that remains to be seen…..Brett
Reply to Brett ==> You should be able to derive the names of the major studies from the 7 study chart, even in Spanish, I was able to download all of them (I think) — or at least view online. There are calculations of water volume – though, in my opinion, rather rough. If you’d like, I’ll post links for the studies that I have.
Thankfully, google translates the Neiba pdf, without maps, not a great problem. Brett
After spending a while on Google maps I don’t see any evidence of threatened buildings; it seems the people are well aware of the potential for rising water, which was probably learned from past experience. They don’t build much below sea level. The dead trees don’t appear to be more than a few decades old. Here a tree ring study might be useful, but photographs are better. –AGF
Reply to agfosterjr ==> In today’s available Google Earth view of Lago Enriqullo the flooded fields and villages are clearly visible — look on the southern shores, on the north side of Hiway 46, about six miles west of Duverge. Not all the Google Earth image quads are of the same date (or even the same year). The buildings, homes, in this area are simple concrete block houses smaller than a two car garage — but you can see the grid of streets through the water and the outlines of fields. There is nothing faked about he problems faced by the poor peasants here…their homes and fields are really flooded.
You are right that there is not much to see….by American standards, there is not much there, but it is all those people have.
The poor, of course, have built homes and cultivated fields on flood plains, areas of land that were under water in the 1960s, because the land was empty, not being used, and didn’t belong to someone else!
I’m a retired Air Force imagery analyst. I spend a lot of time looking at Google Earth. The dates of the imagery for this lake range from 2002 to 2013, and the area inundated by the extra water is readily visible. There’s an island in the lake that’s a national forest. The date of the small bit of imagery on the eastern end of the island is 2002, and the imagery of the rest of the island is 2011. You can readily see how far the water has encroached on the island. The water on the eastern end of the lake has encroached between four and five miles between 2003 and 2013. There are several roads that have been covered along the south bank of the lake on the western end, forcing the government to build new roads. If the lake continues to grow, the town of Boca de Cachon is in danger of being flooded.
Looking at the extent of the flooding, one has to wonder about the loss of livelihood for the entire area. More refugees fleeing to Santo Domingo?