Campo de Perizes is an extensive fluvial-marine plain, with halophilous floodplain grasslands, located between the cities of São Luís, Bacabeira, and Rosário, in the region.

Geography

The Golfão and Baixada Maranhense region was shaped by successive movements of marine transgression and regression over thousands of years. The separates the island of Upaon-Açu from the continent and connects the Bays of

São Marcos São Marcos is a municipality in the state of Rio Grande do Sul, Brazil. As of 2020, the estimated population was 21,658. See also *List of municipalities in Rio Grande do Sul This is a list of the municipalities in the state of Rio Grande d ...

and São José/Arraial. Over it, the was built, consisting of an entrance bridge and an exit bridge; the Benedito Leite Metallic Bridge, belonging to the

São Luís-Teresina Railway The São Luís-Teresina Railway (Portuguese language, Portuguese: ''Ferrovia São Luís-Teresina''), also known as the EF-225, connects the cities of São Luís, Maranhão, São Luís (MA) and Teresina (PI), passing through Timon, Maranhão, Timon, ...

; the duplicated bridge of the

Carajás Railway The Carajás Railway (; EFC or EF-315) is a railway line linking the cities of Parauapebas, Pará and São Luís, Maranhão Maranhão () is a States of Brazil, state in Brazil. Located in the country's Northeast Region, Brazil, Northeast Re ...

; and the metallic bridge that supports the Italuís water main, which takes water from the

Itapecuru River The Itapecuru River () is a river in the Maranhão state of northern Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-l ...

to the city of São Luís. The coast of Maranhão is marked by the presence of

mangrove A mangrove is a shrub or tree that grows mainly in coastal saline water, saline or brackish water. Mangroves grow in an equatorial climate, typically along coastlines and tidal rivers. They have particular adaptations to take in extra oxygen a ...

s; a plant formation of arboreal or shrubby size, adapted to marshy terrain, subject to the direct influence of tides and salinity. It is adapted to the brackish environment, at the outfall of rivers into the sea, where specialized vegetation grows, with a rich variety of aquatic species. In areas contiguous to the mangroves, especially in the Golfão Maranhense region, there are extensive flat areas, subject to periodic flooding and with a predominantly herbaceous stratum, locally called Campo de Perizes. Some of the existing species are the piri or piripiri (''Cyperus giganteus''), which inspired the place's name; the aturiá ('' Machaerium lunatum''); canarana (''

Panicum ''Panicum'' (panicgrass) is a large genus of about 250 species of Poaceae, grasses native throughout the tropical regions of the world, with a few species extending into the northern temperate zone. They are often large, Annual plant, annual or P ...

'' spp); as well as reeds from the

Cyperaceae The Cyperaceae () are a family of graminoid (grass-like), monocotyledonous flowering plants known as wikt:sedge, sedges. The family (biology), family is large; botanists have species description, described some 5,500 known species in about 90 ...

family. The Perizes River flows through the region, which is also close to the outfalls of the Itapecuru River (to the east) and the

Mearim River The Mearim River () is a river in Maranhão state of northern Brazil. The river originates in the southern part of Maranhão, and drains north into the Baía de São Marcos, an estuary that also receives the Pindaré and Grajaú rivers, which ar ...

(to the west). Some consider the Perizes field to be part of the Baixada Maranhense region. In May 2018, the new Italuís pipeline went into operation, replacing 20 kilometers of piping in the Campo de Perizes region. The Italuís System was set up in 1982 and supplies 60% of the homes in the capital of Maranhão. The deterioration over time contributed to the pipeline's frequent ruptures, compounded by the area's salinity, which accelerates corrosion. The new pipeline enabled a reported 30% increase in water flow.

Environmental protection

The

Upaon-Açu/Miritiba/Alto Preguiças Environmental Protection Area The Upaon-Açu/Miritiba/Alto Preguiças Environmental Protection Area () is an environmental protection area in the state of Maranhão, Brazil Location The Upaon-Açu/Miritiba/Alto Preguiças Environmental Protection Area (APA) covers all or pa ...

was set up to preserve the region, which has experienced significant changes due to anthropization, with discussions about creating new conservation units.

Duplication of BR-135

The Campo de Perizes is crossed by the

BR-135 BR-135 is a federal highway of Brazil. The 2518 kilometre road connects São Luís to Belo Horizonte. The road passes through the MATOPIBA region (in the south of Maranhão and Piauí and in the west of Bahia), which is an important producer of ...

highway (Km 25 to Km 51.3), the only highway access to São Luís, with a daily traffic of more than 25,000 vehicles, providing access to the Itaqui port complex and Ponta da Madeira. In 2018, its duplication work was completed between São Luís (Estiva, Km 25) and Bacabeira, where car accidents have been reported over the 26 km extension. The work involved the construction of a viaduct in Bacabeira (Km 51), allowing access to the city of Rosário, at the junction with the BR-402 highway, the gateway to Barreirinhas and the Lençóis Maranhenses. Work on the stretch, which began in 2012, cost R$ 503 million. Due to the soft soil and subject to flooding, especially in Campo de Perizes, the road engineering involved the use of soil improvement technology with gravel columns every 2 meters, with a depth of between 5 and 18 meters, along almost 18 km, used for the first time in Brazil on a long stretch. The São Luís-Teresina railroad tracks and the Italuís system water main, which bordered the highway, were relocated. The presence of the highway, together with electrical, railway, and supply infrastructures, as well as irregular urban expansion, are contributing factors to changes in the ecosystem of Campo de Perizes and other conservation units.

References

{{Reflist Geography of Maranhão Plains of Brazil Protected areas of Maranhão