The Salar de Uyuni Bolivia
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| Reflejo de las Nubes |
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| The reflection of the clouds on the salar |
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| Volcán Tunupa |
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| Pilares de sal |
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| Mountains and jeeps near Salar de Uyuni |
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| Reflections during the sunrise |
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| Reflections |
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| Salt formations |
The area that today occupies this desert was covered 40,000 years ago by Lake Minchinnota 1 and later, 11,000 years ago, by Lake Tauca or Tauka. Note 2 The Coipasa salt flat and the Poopó and Uru Uru lakes are also vestiges of these great prehistoric lakes. These reached a height of around 100 m above the current level of the salt flat and covered the current Uyuni and Coipasa salt flats, and the Poopó and Uru Uru lakes. In this period, a wet climate phase, with more rains than at present, raised the level of protolagos to approximately 100 m above the current level. Later came a dry and warm period, which produced a great reduction of the surface and volume of the Andean lakes, thus originating the salt flats and the current lagoons.
Salar de Uyuni, in addition to the above, contains very important compounds for basic and industrial chemistry. In Bolivia, in a geological past, extensive lakes existed more extensive than the present ones, known by the names of Ballivián, MinchÃn and Tauca. The first has been a predecessor of Lake Titicaca; the second one extended from Uyuni towards the north and the Tauca lake, by evaporation, gave origin to the salar of Uyuni.
Economic influence
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| Sunrise on the salar |
Satellite calibration
Due to its large size, high percentage of smooth surface and high reflectivity, when the water cover that covers it during a low season, the surface of the Salar de Uyuni works up to five times better for the calibration of satellites than the use of the surface of the ocean. In September 2002, a team took the elevation measurements with the Global Positioning System (GPS) detailed of a part of the salt floors, which were used to evaluate the accuracy and precision of the ICESat instruments.
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There are approximately eleven layers of salt, with thicknesses ranging from less than one meter to ten meters3. The crust that is on the surface has a thickness of ten meters. The depth of the salt is 120 meters, which is composed of layers of superimposed brine and lake mud.
This brine is composed of lithium, boron, potassium, magnesium, carbonates (borax) and sodium sulfates. A very interesting mineral is ulexite, the "television stone". It is transparent and has the power to refract the image of what is below to the surface of the stone. This salt is considered the largest reserve of lithium, although it is very difficult to extract due to lack of water.
Flora and fauna
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| Vizcacha Boliviana |
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| Chloephaga melanoptera |
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| Oreotrochilus estella |
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| Lycalopex culpaeus |
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| Vicuñas cerca del Salar |
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| Phoenicoparrus andinus al sur del salar |
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| Phoenicoparrus jamesi |
Tourism
The Salar de Uyuni is one of the main tourist destinations of Bolivia since it is visited by approximately 60,000 tourists every year:
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| Hotel of salt |
- In the month of November it becomes the place of breeding of three species of flamingos: the austral flamenco, the big parina, and the small parina.
- Giant cacti up to 10 m high are found on the island of Pescado. This island is the largest of the set of islets located in the center of Salar de Uyuni. It is also a tourist center inside the salar.
- Mummies of 3000 years old were discovered in a cavern on the edge of the salt flat.
- On the banks of the salt are several hotels built with blocks of salt, a feature that places them among the most extravagant hotels in the world.
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| Isla Incahuasi |
Weather
The following tables show the average monthly and annual values of temperature, relative humidity, winds and insolation in the meteorological stations of the region. The temperature can be related to the altitude and latitude, but also to the exposure of the place.7
Average minimum temperature in ° C
| Localidad | Ene | Feb | Mar | Abr | May | Jun | Jul | Ago | Sep | Oct | Nov | Dic |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Uyuni | 4.9 | 4.2 | 3.0 | -1.8 | -7.4 | -10.3 | -11.7 | -9.4 | -6.6 | -3.3 | -0.5 | 2.6 |
| Colcha K | 6.2 | 4.3 | 4.6 | 1.8 | -2.9 | -3.2 | -3.4 | -2.4 | -0.5 | 0.9 | 8.0 | 4.5 |
| Oplaca | 10.4 | 10.3 | 9.5 | 6.8 | 3.8 | 9.9 | 0.9 | 2.5 | 5.2 | 7.7 | 9.4 | 9.9 |
| RÃo Mulatos | 4.6 | 3.5 | 2.5 | -0.3 | -7.2 | -8.7 | -11.0 | -9.6 | -8.8 | -2.7 | 0.3 | 2.8 |
Average maximum temperature in ° C
| Localidad | Ene | Feb | Mar | Abr | May | Jun | Jul | Ago | Sep | Oct | Nov | Dic |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Uyuni | 20.7 | 20.4 | 20.4 | 18.4 | 14.8 | 12.4 | 12.4 | 14.9 | 16.1 | 19.1 | 21.0 | 21.4 |
| Colcha K | 20.2 | 20.3 | 19.2 | 18.5 | 14.2 | 13.2 | 12.9 | 15.7 | 17.2 | 19.1 | 28.3 | 20.8 |
| Oplaca | 24.8 | 24.5 | 24.2 | 23.1 | 20.4 | 18.1 | 18.2 | 26.2 | 22.9 | 25.6 | 25.1 | 26.1 |
| RÃo Mulatos | 16.8 | 16.8 | 16.8 | 16.7 | 14.9 | 12.7 | 12.9 | 14.3 | 14.8 | 17.9 | 17.7 | 17.9 |
Average temperature in ° C
| Localidad | Ene | Feb | Mar | Abr | May | Jun | Jul | Ago | Sep | Oct | Nov | Dic | Año |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Uyuni | 13.2 | 12.8 | 12.6 | 9.3 | 4.7 | 2.6 | 1.7 | 4.4 | 6.4 | 9.3 | 11.6 | 13.0 | 8.5 |
| Colcha K | 13.2 | 12.3 | 11.3 | 10.2 | 5.7 | 5.0 | 4.8 | 6.6 | 8.4 | 10.0 | 11.7 | 12.7 | 9.4 |
| Oplaca | 17.8 | 17.4 | 16.9 | 14.9 | 11.7 | 9.5 | 9.6 | 11.4 | 14.8 | 16.9 | 18.3 | 18.0 | 14.7 |
| RÃo Mulatos | 10.7 | 10.0 | 9.5 | 7.9 | 3.9 | 2.0 | 1.4 | 2.4 | 3.4 | 7.6 | 9.0 | 10.0 | 6.5 |
Relative humidity in%
The relative humidity is low. Highlights the average recorded value of 33.5% at the Uyuni weather station.
| Localidad | Ene | Feb | Mar | Abr | May | Jun | Jul | Ago | Sep | Oct | Nov | Dic | Año |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Uyuni | 43.5 | 43.5 | 40.9 | 33.1 | 32.9 | 32.5 | 31.1 | 28.4 | 27.9 | 25.8 | 27.8 | 34.3 | 33.5 |
| Colcha K | 52.6 | 44.1 | 50.2 | 36.9 | 34.5 | 34.7 | 32.8 | 29.9 | 28.1 | 26.2 | 30.5 | 39.9 | 36.7 |
| Oplaca | 54.7 | 59.5 | 52.5 | 44.3 | 40.8 | 40.5 | 39.8 | 38.7 | 38.7 | 40.8 | 45.5 | 40.5 | 44.8 |
Relative humidity in%
The relative humidity is low. Highlights the average recorded value of 33.5% at the Uyuni weather station.
Physiographic characteristics of the basin
The Salar de Uyuni basin is an endorreic, meaning it has no outlet to the sea. The Salar de Uyuni and its basin of contribution occupy a total area of more than 60,000 km2. The basin is composed of two main basins: the basin of the Grande de LÃpez river and the Colorado river basin (Puca Mayu) and the Uyuni salt flat itself.
By means of the Negrojahuira stream, which is around 20 km long, the Uyuni salt flat is connected to the Coipasa salt flat.
The main geomorphological parameters corresponding to the hydrographic basin are:
Frequency of rivers
It is defined as by the total number of rivers divided with the area of the basin. It is measured in rivers / km². For the Uyuni salt basin, the frequency of the rivers is 0.28 rivers / km².
Length of the main channel
It is defined by the water course that reaches the longest in a basin. For the basin of the Grande de Lipez River, the longest length belongs to a tributary, the Quetena River, with 130 km, while the Grande River reaches 90 km.
Average slope of the basin
In the basin there are scattered areas of steep inclination, particularly in the border area with Chile, with slopes greater than 20%, while in the central and final part of the basin the slope is almost horizontal, with values that do not exceed 3% inclination It is evaluated that the weighted average of the slopes, defined as the Average Slope of the basin, is around 5%.
Water availability of the basin
The availability of water resources in a region is determined by its climatic characteristics. It is a region that presents adverse climatic conditions reflected in a permanent water deficit, as a consequence of the differences between precipitation and evaporation. However, the presence of an appreciable amount of surface water is noticeable in the region: lagoons, salt flats and bofedales; this is due to groundwater, which in some way define the hydrological characteristics of the region; that is to say, the formation of lagoons and bofedales on the surface depend on the contribution of groundwater.
In fact, the waters that flow in the region are, in their great majority, of underground origin and also, old. An important part of the water stored in the underground aquifers should be considered a non-renewable resource, because it comes from rains that occurred in distant geological times.
Studies carried out in the area agree that recharge of aquifers in the Lipez region is currently very weak or almost non-existent According to Chaffaut, the recharge of these aquifers could have occurred in a period between a few hundred and several thousands of years, in which the climatic conditions were different from the current ones; Studies have confirmed that the contribution of recent rainfall waters to the water flows that travel along the surface of the basins is low, usually less than 10 percent. It would then be non-renewable water resources. The environmental and social impacts of an irresponsible use of these resources could be irreversible.
Groundwater
As regards the Uyuni basin, whose extension is approximately 60,000 km², the losses and external contributions to the river basin are limited both in the east-west circulation and the fact that currently, with respect to the north-south circulation, the piezometric difference between Popoo, Coipasa and Uyuni is several dozens of meters, then a direct link seems unlikely.
From the point of view of rainfall it can be assumed that everything that precipitates in the Uyuni basin converges in the Uyuni salt flat.
It should not be forgotten that the evapotranspiration in the free surface is more than ten times the precipitation, then any water that after an underground road returns to the surface, is subject to this phenomenon (secondary evapotranspiration). From this derives the reduction over time of the surfaces of the water in the lakes, lagoons and in the salt can be indicative of the state of equilibrium of the hydrogeological system.
As regards the west-south-west area, where the Cordillera area is mostly made up of volcanic rocks (lava and tuff), there is not always a correspondence between hydrographic and hydrogeological basins (eg Fuentes Silala and Alota). In the other study areas, where the terrain is constituted by Paleozoic, Mesozoic or Tertiary terrigenous rocks, there is a good correspondence between hydrographic basin and hydrogeological basin.
In relation to the quantitative water can calculate: if the average precipitation is around 200 mm / year and if these, considering the hydrogeological situation of the area, infiltrates 10% and this amount can be made available 5 %, very high per capita quantitative results are obtained.
Considering that, although the calculations were exaggerated in terms of rainfall, infiltration, removal of infiltrated water and secondary evapotranspiration, and considering that the population density is very low, in any case they would be quantitative of renewable water higher than the needs of the entire population, agriculture and livestock.
On the other hand, if it is true that in some local situations over-exploitation of the stratum has occurred, it is also true that this problem loses its relevance in a general perspective. From the point of view of the waters, it is difficult to make a forecast about the type of water that is found during eventual drilling because, as mentioned, the main aquifers are connected to tertiary or quaternary deposits characterized by very discontinuous lake lacustrine deposits. the area, with occasional presence of evaporite levels and displaced to several heights by the effect of differential tectonics (origin of salty rivers).
Aquifers with better characteristics seem connected to water circulations in lava formations, while pyroclastic volcanic formations seem to act as impermeable barriers.
On the other hand, there is a problem of water quality, because most of these, in their underground road, are loaded with salt and sometimes re-surface, originating rivers of salt water (do not forget that the water exchange between the rivers and the sub-alveo flow is continuous), salty sources and salty resurfaces. Unfortunately, it is difficult to foresee in detail the location of the ancient evaporite levels both in terms of areas and depth, although in general, as it comes out of the drilling data and those related to surface water, proceeding in depth and in the direction of the Salar de Uyuni the quality of the water worsens because the problem of these evaporitic deposits are present from the Miocene to the present time and the thickness of this sequence can reach several hundred meters.
From the point of view of water quality, an additional problem is associated with the presence of boron in waters related to effusive volcanic rocks. This problem affects more or less sensitive all the waters of the area. In this sense, an outline of the analyzes carried out that shows how Boron and Arsenic, which can sometimes be a further problem with respect to which already treated by salinity, is attached. On the other hand, given the different tenor of Boro present, detected in wells and sources sometimes in very different and substantial quantities, some strategic decisions will be affected not only by the amount of salinity or water available, but also by the cost of the reduction of these elements, Arsenic and Boron.
Water quality
There are two types of water sources in the region that have different hydrogeological origins and therefore completely different qualitative characteristics: groundwater and springs or sources of fresh water. The groundwater in the sub-basin of the Grande de LÃpez River is saline. Consequently, the water that flows through the Grande de LÃpez River, partially fed by groundwater, is also salty and of poor quality from its encounter with the Salado River, which is why it is not used as irrigation water and even less so. as a source of water for human consumption by the inhabitants of the communities of the region through which this river flows. On the other hand, in the region there are fresh water springs that are generated by the sub-superficial flow of rainwater and that emerge mainly in the upper areas of the micro-basins. These springs are used as sources of drinking water by almost all the communities in the region. Despite the volcanism of the area, most of the springs in the region have waters of good physical and chemical quality, except for the almost constant presence of boron in concentrations higher than those allowed by the Bolivian Standard for human consumption. From this it can be inferred that the underground aquifers that give rise to these springs also have good quality waters. Only the aquifers located next to salt flats and salted lagoons have waters with a high content of salts. Special mention is made of the waters of the Silala spring, which is located on the border with Chile. It is freshwater, with an average flow of 200 l / s.
Geology of the Uyuni salt basin
The geology of the Salar de Uyuni basin is represented by Paleozoic formations, few Mesozoic, and mainly Cenozoic formed by volcanic rocks and vulcano-sedimentary sequences. In the area of influence of the Salar de Uyuni, recent (Quaternary) sediments are found grouped in saline deposits, alluvial, fluvial, lacustrine, fluvioglacial, moraine and dune deposits. The geological map also shows a very complex tectonic situation that interests both the Paleozoic formations such as the Cenozoic. The orientation of individual leaf systems indicates a situation that has changed over time and a rather complex structural framework.
In particular, in the area there are:
- Lava flows, pyroclastic deposits, stratovolcanoes and domes;
- Alluvial, fluvio-lacustrine, fluvio-glacial and glacial deposits;
- Flows of lava, tuffs, stratovolcanoes and vulcano-sedimentary successions;
- Welded tuffs and lavas interspersed with tuffs.
Lithium Triangle
Main article: Lithium Triangle
The "lithium triangle" refers to a geographical area located in South America, on the border of Bolivia, Chile and Argentina.
The triangle is made up of the Salar de Uyuni (Bolivia), the Salar de Atacama (Chile) and the salar of the Dead Man (Argentina), so-called because between the three salt flats located in the puna together with others close to these they concentrate more of the 85% of the known lithium reserves of the planet.
Although there are no industries in the area that work properly with the material or any added value is made to the mineral, the work that is done in the area is limited only the extraction of the raw material by foreign mining companies that export the material to countries such as the Netherlands, Russia, EE. UU., China, United Kingdom, Germany among others and / or by automotive companies such as Toyota, Mitsubishi and Magna batteries.
According to experts, the area of the triangle contains lithium resources equivalent to oil in Saudi Arabia and is considered a "strategic resource" because of its future projection because lithium is an indispensable input for energy supply in the country. cellular, computers, modern cars (hybrids and electric) and a wide range of technologies such as glass, ceramics, lubricating greases, in the pharmaceutical industry, among others, so in recent years the area is strongly appreciated by both foreign countries and local and by mining companies and private companies and multinationals, being today studied by local countries in order to know their true industrial potential.
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