Bart Schultz
The country is predominantly covered by tropical rainforest, with only the coastal plains being developed. Due to its location near the equator, without any particularly high elevations, it is hot and humid year round. Most areas experience heavy rainfall from December to June or July. Between August and November, the eastern half of the country experiences a dry season, resulting in a tropical monsoon climate. The western half has a tropical rainforest climate.
To better drain excess water from the low-lying coastal plain, a group of Barrancoids were the first to construct raised fields around 300 BC. Such fields are found in various parts of South America, particularly along the edges of the rainforest in the Amazon River basin. They were intended to provide a dry area for growing crops and concentrating fertile soil. Most of these fields date from the first millennium BC, but some were constructed as early as 1000 BC. They remained in use until European colonization in the 18th century and even beyond.
Most of the earthmoving was accomplished in connection with the Arauquinoid settlements. They constructed thousands of raised fields in various shapes, dug ditches and canals, laid paths, and built mounds to establish their villages. The first Arauquinoid fields were created in 650. Between 1000 and 1450, they expanded along the northern coast of South America to an area approximately 210 kilometres long and 25 kilometres wide.
The raised fields appear to have been constructed in homogeneous, adjacent areas, each averaging 0.5 hectares. Archaeologist Stéphen Rostain distinguished four types of raised fields:
- ridge-shaped fields in Guyana, Suriname, and French Guiana. These fields were between 1 and 3 metres wide, 5 to 30 metres long, and 30 to 80 centimetres high. They were shaped like the slope between the sand ridges and the marsh. Their distribution was related to the elevation and water level;
- large raised fields ranging in size from 2 to 5 metres in diameter and 30 to 100 centimetres high. These usually circular fields were constructed around the villages of Kourou and Sinnamary, and also in eastern Suriname. They were more square or rectangular near the island of Cayenne. These large raised fields were located in the most flooded areas and were smaller in the deepest marshes;
- medium sized raised fields. These fields could be circular, square, or rectangular and were found only in French Guiana. Their size ranged from 1.5 to 3 metres in diameter and 20 to 30 centimetres in height. They existed in large clusters;
- small, rounded raised fields. These fields ranged in size from 50 to 100 centimetres in diameter and from 20 to 50 centimetres in height. These fields, too, have only been found in French Guiana.
The location of the raised fields between the higher and lower areas of the landscape suggests careful selection by the Native Americans. However, this was not always sufficient to prevent flooding. Ditches were dug to improve water management.
To drain excess water from the raised fields during the rainy season and most likely to serve as reservoirs during the dry season, ring ditches were dug around some groups of raised fields. These drained the water into canals that could be approximately 150 metres long. Besides draining excess water, the canals may also have served as reservoirs or fishponds. Some were so long that they were also suitable for transport by canoe.
Only a limited number of polders were constructed in French Guiana, most of them in the 18th century in the downstream part of the Approuague River basin. French historian Yannick Le Roux distinguished three phases in polder development:
- the first (1764-1794) is characterized by the abandonment of raised fields and the experimentation with early polders;
- the second (1815-1848) is geared towards the success of a pre-industrial form of agriculture, well-adapted to lowlands;
- the final phase is contemporary, involving the resumption of polders for aquaculture and rice cultivation in the Mana region.
Under the influence of Samuel Guisan - who had witnessed the construction of polders in Suriname - slaves began constructing polders between the Oyapock River and the island of Cayenne in 1769. The rice polders near Mana, created around 1980, covered 50,000 hectares, divided into 200x600 metres sections surrounded by dikes and canals. Only a few of these polders are still in use for rice cultivation. A brochure from the Conservatoire du Littoral noted that the Mana polder - here called Polder Sarcelle - was in a poor agricultural condition and that part of it was converted into a nature reserve in 2010. The Polder Development Group mentioned the 360 hectares polder on the Mahary River Marie-Anne.
