Мексиканың Сумидеро каньоны ұлттық паркі

National park in Mexico

Sumidero Canyon (lang es) is a deep natural canyon located just north of the city of Chiapa de Corzo in the state of Chiapas, in southern Mexico. The canyon's creation began around the same time as the Grand Canyon in the U. S. state of Arizona, by a crack in the area's crust and subsequent erosion by the Grijalva River, which still runs through it. Sumidero Canyon has vertical walls which reach as high as , with the river turning up to 90 degrees during the length of the narrow passage. The canyon is surrounded by the Sumidero Canyon National Park, a federally protected natural area of Mexico which extends for over four municipalities of the state of Chiapas. This park is administered by the National Commission of Protected Natural Areas (CONANP). Most of the vegetation in the park is low to medium height deciduous rainforest, with small areas of mixed pine oak forest and grassland. At the north end of the canyon is the Chicoasén Dam and its artificial reservoir, one of several on the Grijalva River, which is important for water storage and the generation of hydroelectric power in the region. The canyon and national park is the second most important tourist site in Chiapas, drawing mostly Mexican visitors who see the canyon from boats which embark on the river from Chiapa de Corzo. The park borders Tuxtla Gutiérrez, the state's largest city, which has caused problems with human encroachment and settlement on park land. More importantly, the urban areas and logging industries upstream from the canyon have caused serious pollution problems, with up to 5000 tons of solid waste extracted from the Grijalva River each year. This waste tends to build up in the canyon because of its narrowness, the convergence of water flows and the presence of the Chicoasén Dam.

The Sumidero Canyon was formed by cracks in the Earth's crust along with erosion by the Grijalva River, which still flows through it. The process of its formation began about 35 million years ago, making the Sumidero contemporary with the Grand Canyon on the Colorado River. In addition to the Grijalva, there are other flows of water in the area in and around the canyon, many of which are seasonal. These consist of streams, some of which form waterfalls on the canyon's sides, and underground movements which have created caves and karst formations. These walls expose a long process of disturbance in the Earth's crust with layers of limestone from the Upper Mesozoic, which contain fossils of marine creatures. During the Mesocretac Period, there was an elevation of ocean floor which formed much of the mountains of the area. and the American crocodile, which can be seen on the riverbanks. In another small cave, there is a stalactite called the Caballito de Mar or "Seahorse" after its shape.

Despite its biological, ecological and cultural diversity, there have been few studies performed in the park area. For this reason, there is a lack of information about species, habitats and water flow. There is also relatively little information about how human activities affect the park. The center of the park is the Sumidero Canyon and the Grijalva River that runs from south to north through it. The park's borders on this river are marked by the Belisario Domínguez Bridge, over which the Pan American Highway runs, in the south and the Chicoasén Dam, to the north. The park is divided into four sections by direction: the northwest includes medium height, somewhat deciduous rainforest as well as some lowland rainforest and grassland, found in the municipalities of Osumacinta and San Fernando; the western section has similar vegetation, and is located entirely in San Fernando; the eastern section has forests of pine as well as medium height semi deciduous rainforest and grasslands, and is found in Chiapa de Corzo; and the southeast has most of the sides of the canyon itself and a navigable section of the Grijalva River, but only remnants of medium height rainforest and pachycaulous vegetation. The main land access into the park is from Tuxtla Gutiérrez north through Osumacinta then past the Chicoasén Dam. Another access point is from Chiapa de Corzo by boat from the Cahuaré Docks. Most of these illegal constructions belong to the very poor who have migrated to the city from elsewhere. The demand for living space has created an industry of illegal subdivisions which are then sold without the proper title to victims. Three of the main neighborhoods to develop in this way are the Patria Nueva Alta, Arroyo Blanco, La Esperanza and Las Granjas. The encroachment is a result of the fast population growth of Tuxtla Gutiérrez and Chiapa de Corzo. The growth of these areas has led to land ownership disputes, loss of wild habitat and deforestation. In 2002, the federal and state government signed an accord to remove illegal human settlements and work to prevent further encroachment. Much of the sewage comes into the Grijalva via the Sabinal River, which carries most of the waste water of the city of Tuxtla Gutiérrez. In addition, trash and raw sewage makes its way into the river from the various tributary streams. The most obvious pollution is garbage, especially plastic containers, which mostly comes from area homes and businesses tossed onto the ground or in streams, especially from Chiapa de Corzo and Tuxtla Gutiérrez due to the lack of environmental awareness according to Conanp. The quantity of this trash reaches its height during the rainy season, when runoff and swollen streams can carry more of it into the Grijalva. Somewhere between 80 and 90% of the waste solids found in the river is branches, wood, rocks, sediment and other debris from legal and illegal logging, which cause deforestation These mostly come into the river during the rainy season, especially from the Villa Flores and Villa Corzo municipalities. As the solids flow along the Grijalva, they are constricted by the narrow channel of the canyon and then by the presence of the Chicoasén Dam. There are year round and seasonal efforts to clean the river within the canyon and the area just upstream from it. Much of the daily effort is undertaken by workers with the Comisión Nacional de Áreas Naturales Protegidas (CONANP) and the Secretariat of Tourism in Chiapas, which extract twelve tons of garbage from the Grijalva river each day. Efforts can involve up to 600 people at a time using 32 boats from four of the tourist cooperatives. As they take visitors from Chiapa de Corzo or Tuxtla Gutiérrez through the canyon and to the dam, they provide environmental, historical and cultural information. These are the most organized tourist activities in the park. For those who choose to see the canyon from the lookout points above, there are restaurants and other food service places as well as camping and picnicking facilities. Extreme sports include mountain biking, rappelling, spelunking and more. Rappelling allows for access to many of the canyon's small caves which are not accessible any other way.

At the northern end of the Sumidero Canyon is the Chicoasén Dam, formally called the Manuel M. Torres Dam, is one of a number of dams which have been built along the Grijalva River for water storage and the generation of hydroelectric power. This dam and its reservoir is considered to be part of the Sumidero Canyon system. The Sumidero Canyon National Park is defined on the north end of the river by this dam and the Belisario Domínguez Bridge on the south. The dam was constructed between 1974 and 1980. The reservoir covers an average of 2,193 hectares, and the complex employs about 600 workers. The Chicoasén Dam produces electricity and manages the flow of the Grijalva river along with the Hondo River and the Muñiz, El Jardín and El Cacao streams, which converge to form the Osumacinta River. This reservoir is one of the most important in the country. The hydroelectric station is also one of the most important in the country with thirty generators with installed capacity of 3,928.48 megawatts. This is just over thirty percent of all hydroelectric energy produced in Mexico.

The history of the area is connected to the Chiapa people, who occupied the Central Valley area before the arrival of the Spanish. The origin of these people is not known, but theories have them migrating north from Nicaragua or even Paraguay. Their main settlement was in Chiapa de Corzo near the canyon, with a fortified area in the higher areas in the canyon for protection from invasions. The Chiapa fiercely resisted Spanish conquest and were not subdued until the arrival of Diego de Mazariegos in 1528. Their last refuge was in the fortified area, now known as the archeological site of the Ruins of Berlin. Here the last of the Chiapa held out from 1528 to 1535 after the Spanish took over the main city. Legend states that when this last fortification fell, the remaining Chiapa committed collective suicide by jumping into the canyon. Since then, the canyon has served as a boundary marker between the Zoque and Tzotzil peoples. Until the 20th century, the canyon area was relatively unexplored. In 1895, three Frenchmen attempted to explore the canyon but were drowned in the river. An American came in 1932 but also perished. This gave rise to legends about witchcraft in the areas as well as the ferocity of the area's crocodiles. In 1960, an expedition of soldiers from the Mexican army, nicknamed the "red handkerchiefs" succeeded into crossing through the canyon by boat over twenty km. This opened up the canyon to local exploration and exploitation, including rudimentary tourism and the hunting of crocodiles and other native fauna. There has been little archaeological work done in the area. The main site is called the Ruins of Berlin, named after German explorer Heinrich Berlin, who visited the area in 1946 and named the area "Sumidero". This site is located seven km from the Belisario Domínguez Bridge in Tuxtla on the edge of the river. It covers an area of 467 by 60 meters, bounded by small mounds surrounding patios. The original description of the site was undertaken in 1923 and 1932 by Becerra, who called it Chiapa Viejo, and stated it was the capital of the Chiapa people. However, Remesal in 1966 determined it was a secondary site. The last major survey was done in 1976 by Alejandro Martínez, discovering that there are 24 individual sites of which nine are mounds and fifteen are in caves. One of these contains cave paintings which indicate that the area has been occupied since at least the very early Pre Classic period.