GRIJALVA RIVER: HISTORY, CHARACTERISTICS, ROUTE, TRIBUTARIES, FLORA, FAUNA - GEOGRAPHY - 2024

The Grijalva River is an international river shared between Guatemala and Mexico. It is born at more than 4,000 meters above sea level and flows through the American continent until it reaches the Atlantic Ocean.

Its basin drains an area of ​​58,025km ², of which 10% is in Guatemala and the other 90% belongs to Mexico. Its flow of 36,500 million m ³ per year makes it the largest producer of hydroelectric energy in Mexico.

El Sumidero Canyon in the El Sumidero Canyon National Park, which crosses the Grijalva River. Photo: Juan de Vojníkov at Czech Wikipedia

History

Primitive and refined agricultural cultures settled on the banks of the Grijalva, using it as a pantry for vegetable, animal and medicinal plants essential for their subsistence.

The documentation of history on the Grijalva River began in 1519 with the arrival of the expeditionary Hernán Cortés along with his entire army on March 12. With this arrival it was sought to continue the exploration and conquest of the territory of New Spain, present-day Mexico, through the mouth of the Grijalva River in the state of Tabasco.

During the conquest and the colony, the Spanish kingdom used the waters of the Grijalva to connect its settlements and move American products such as cocoa and hardwoods to supply European markets.

In the 19th century, the nascent Mexican government had to confront the expansionist intentions of the United States government. In October 1846 an American squadron made up of steamships and schooners, commanded by Commodore Mathew C. Perry, went up the mouth of the Grijalva River without landing, due to the defense actions undertaken by the inhabitants of the banks.

Sixteen years later, the convulsed Mexican territory had to face another invasion, this time of European origin. In 1862 the inhabitants of Tabasco organized again to defend the banks of the Grijalva River against French troops. The clashes lasted two years and culminated in the withdrawal of the invaders on February 27, 1864.

In the twentieth century, during the Mexican Revolution, the revolutionaries and the national government moved through the waters of the Grijalva, proselytizing, teaching lessons, and seeking allies to join their factions.

Until 1956, with the junction of the Gulf Highway with the Federal Capital, the Grijalva River was the main communication route that communicated the state of Tabasco with the rest of the Mexican territory.

General characteristics

The Grijalva basin is of great importance for the economic development of Mexico and is constituted as a reserve of biodiversity due to the large amount of rainfall that occurs in the region.

Precipitation

The riverbed is located at the foot of the Sierra de los Cuchumatanes, the Sierra Madre de Chiapas and the Sierra Norte in Mesoamerica. Its geographical location in the depression formed by the elevation of the mountain ranges, right at the meeting of the northern cold front with the tropical air masses, make the Grijalva basin one of the regions with the highest rainfall rates in the world.

It has the highest rate of rainfall in the country, with an annual average that exceeds 2,100 mm, reaching more than double the national average. The rate of rainfall in the basin varies considerably as the river moves towards its mouth.

In the upper and middle Grijalva there are between 1,200 and 1,700 mm on an annual average. These dry conditions are generated by the Föen effect, produced by the meeting between the masses of humid and warm air. This effect pushes the precipitations towards the Grijalva in Guatemalan territory, from where they flow feeding the riverbed.

The lower Grijalva sector, located in the Sierra Norte, receives the highest rainfall rate in the basin with annual averages over 4,000 mm. This sector presents rainfall practically throughout the year, registering increases of up to 3 meters in 12 hours. In the Tabasco plain, the average ranges between 1,700 and 2,300 mm.

In the Guatemalan sections, upper and middle of the Grijalva, the rains are more intense in summer, while between autumn and winter there are less intense but longer rains, which generates floods that are concentrated between September and November.

Dams

The population growth generated an increase in energy and food needs that the Mexican government has sought to satisfy by promoting agriculture, cattle ranching and the construction of large hydroelectric plants.

This is how the national government promoted –among other actions– the construction of dams on the Grijalva riverbed, in order to control floods, drain the plains for commercial use and generate electricity.

Six hydroelectric plants are installed on the riverbed, with a total production of 12,817 gigawatts per hour (GWh), representing 52% of the energy generated nationwide.

Between 1940 and the end of the 1980s, the plains of the state of Tabasco went from a cattle occupation of 16% to 63%.

The construction of the dams and the subsequent drainage allowed the establishment of cocoa, citrus, sugar cane, banana and coconut crops in the plains. At the same time, the cultivation of coffee, fruits and vegetables was promoted in the upper basin to take advantage of the temperate temperatures and humidity of the area.

Contamination

The intense exploitation of the resources of the Grijalva river and the growth of cities on its banks has impacted on the quality of the water. The construction of dams has impeded the transport of nutrients and the adequate oxygenation of water, vital elements for the maintenance and subsistence of biodiversity.

To increase agricultural production and control pests in crops, agrochemicals are filtered through the soil and dissolved in the water used for irrigation, eventually reaching the river.

Mining, oil and industrial exploitation, together with the absence of plants for the adequate treatment of wastewater, generates high concentrations of nitrites and nitrates, coliform bacteria, arsenic and mercury in the waters of the Grijalva.

Birth, route and mouth

The Grijalva River is a transnational channel that originates in Guatemala, specifically in the Sierra de los Cuchumatanes in the department of Huehuetenango, at 4,026 meters above sea level and flows through Mexico through the states of Chiapas and Tabasco.

It travels 600 km from its source in the Guatemalan highlands to its mouth in the Gulf of Mexico.

Of its four sections, the first is the Guatemalan Grijalva, which runs from its source in the Sierra de los Cuchumatanes to Amatenango de la Frontera on the border with Mexico. In this section, the river passes from 4,026 meters above sea level from its source to 2,400 meters above sea level and covers an area of ​​6,859 km ².

The upper and middle Grijalva are located in the Mexican state of Chiapas and flow through the depression of the same name. It is located in the center of the state and is constituted as a semi-plain, it limits to the north with the Sierra Norte de Chiapas, to the east by the Altos de Chiapas and the eastern mountains; and to the southwest by the Sierra Madre de Chiapas. They occupy an area of ​​9,643 km ² and 20,146 km ² respectively.

Lower Grijalva is located between Chiapas and Tabasco. In Chiapas it flows through the Sierra Norte through a set of mountainous areas whose disposition traps moisture, combining the cold air masses from the north with the tropical masses from the Atlantic and Pacific. This sector occupies 9,617 km ².

In Tabasco it flows through a plain located in the Gulf coastal plain to its mouth. This sector occupies 12,163km ². Here the Grijalva delta develops, formed at its confluence with the Usumacinta river, presenting wetlands and swamps. Together, these flood zones constitute the biosphere reserve known as Pantanos de Centla.

Main cities that travels

According to the 2000 census, 10 million people inhabited the Grijalva-Usumacinta basin, approximately 4% of the population of Mexico. In its 600 km route, it touches the capitals of the Mexican states of Chiapas and Tabasco: Tuxtla Gutiérrez and Villahermosa.

Tuxtla Gutierrez

This city is the capital and the most important populated center of the Mexican state of Chiapas. In 2015 it had 598,710 inhabitants and is considered one of the best cities to live in Mexico.

The Grijalvase River is located 5 km from the city at a height of 390 meters above sea level, in an area protected by the Cañón del Sumidero National Park. It is located on a geological fault in the Sierra Norte de Chiapas, the canyon walls exceed 1,000 meters above the river level and has a depth of up to 250 meters.

The canyon flows into the artificial lake of the Manuel Moreno Torres dam and is enabled for ecotourism enjoyment with boat rides and kayaks that allow you to admire the fauna and flora of the jungle that occupies the banks.

Land alternatives are also offered to travel the routes on foot or by bicycle, climbing, abseiling and zip-lining. You can also enjoy the panoramic views from the viewpoints.

Beautiful villa

Capital and main economic center of the coastal state of Tabasco. It was founded in 1564 as a port and fishing city due to its strategic location on the Gulf of Mexico. From 1970 it presented a disorderly growth due to oil exploitation and by 2005 it had 614,629 inhabitants.

Villahermosa is located between the Carrizal and Grijalva rivers. The growth of the city produced by the development of the oil industry generated the redirection of river waters with the aim of taking advantage of the land for residential and industrial use.

Tributaries

The Grijalva River receives Guatemalan and Mexican tributaries, among the most important we can mention Cuilco, Pichucalco or Ixtacomitán, Tepe-titán-Chilapa, La Venta, Sayula, Chilapa, de la Sierra, Chicoasén, Teapa, Tzimbac, Yamonho and Chilapilla.

Flora

The Grijalva-Usumacinta basin is one of the areas of greatest biological diversity in Mexico. This derives from the variation in climates and soil types that occur along its route, from a height of more than 4,000 meters to the Atlantic Ocean.

More than 20,000 species of higher plants have been registered, among which 12% are endemic, occupying the first national place in the number of exclusive species in the region.

In the area there are 17 types of vegetation that occupy approximately 47% of the surface of the basin. 49% is dedicated to agricultural activities and animal husbandry, the remaining 4% corresponds to areas without vegetation and human settlements.

In the Guatemalan section and the upper Grijalva, pine and oak forests abound with an important presence of acorn oak, yellow pine or hazelnut, red oak, straight pine or pinabete, common oak, Chahuite pine, acolote, Moctezuma pine or Chamaite.

In the middle section there are humid, high, medium and low forests, whose vegetation varies depending on the height. The most representative species are: wild tamarind, zopo, Honduran mahogany, tanimbuca, tinco, chilacayote, ojoche, guanandí, acacia, guásimo, coloradillo, palo bermejo, amargoso, naked Indian, oaxqueño cedar, pochote, milkweed, curbaril, guanacaste, croton and beans.

Within the savannas of the lower Grijalva there is black olive, nance, siricote, tecomate, coatecomate and bacabuey.

The mangroves and wetlands at its mouth are home to 45 of the 111 species of aquatic plants that have been reported in Mexican territory, among which are arrowhead, black mangrove, anchored water hyacinth, button mangrove, red mangrove, Luziola Subintegra and Micranda Spruceana.

Fauna

Hand in hand with plant diversity, the Grijalva river basin is a reservoir of great biodiversity of fauna. The variability of the climate throughout the basin marks the presence of different species by sectors, some of them endemic, so they are protected or in danger of extinction.

It is estimated that 67% of the animal species recorded in Mexico inhabit the area, 150 species of freshwater fish, 189 species of amphibians, 240 species of birds and 200 species of reptiles.

Some of the most representative of the area are bonefish, river crocodile, tiger snake, Chimalapa guayacón, black snook, hocofaisán, river wolf, Central American stone hand, Tenguayaca, Kinkajú, white heron, nasal leaf bat, turipache mountain, mangrove fox, cormorants, jungle oak and spider monkey.

Also Chiapas skink, white pelican, greater knob scale lizard, howler monkey, brown pelican, West Indian manatee, northern snorting snake, ocelot, white-tailed deer, Mexican tamandua, black-snouted spiny lizard, wild boar, Mexican porcupine, scalloped chipo, boa constrictor, Moorish cat and sword of Clemencia.

References

1. Martínez, Carlos, El Grijalva, a river that flows in history, Revista Signos Históricos, 2005. Taken from redalyc.org.
2. Grijalva and Usumacinta river basin section, website of the National Institute of Ecology and Climate Change. Taken from inecc.gob.mx.
3. Musalem, Karim, Water quality of the Grijalvariver on the Chiapas - Tabasco border. Ecosistemas y Recursos Agropecuarios Magazine, 2018. Taken from scielo.org.mx.
4. Integrated management of floodwaters case study Mexico: Grijalva river, Associated Program for OMM / GWP flood management Taken from floodmanagement.info.
5. Plascencia-Vargas, Héctor, Physical-biotic characteristics of the Grijalva river basin, In the book Mountains, towns and water. Dimensions and realities of the Grijalva basin, 2014. Taken from researchgate.net.