La Mojana
La Mojana is a large area of wetlands in Colombia that functions as an inland river delta.
It lies in the Momposina depression [es], and is fed by water from three rivers: the San Jorge, the Cauca, and the Magdalena.
Distinct wet and dry seasons mean there are significant changes of water levels within La Mojana throughout the year, affecting the environment and human activities.
The waterways continue to play an important role in modern times, shaping agriculture and livelihoods.
Changes to the landscape have also affected the flow of water, damaging soil fertility while also increasing flood risk.
La Mojana is an area of wetlands covering over 500,000 hectares (1,200,000 acres) in northern Colombia, encompassing 11 municipalities within the departments of Antioquia, Bolívar, Córdoba, and Sucre.
[4]: 2 As the terrain is flat, floods, which can reach up to 7 metres (23 ft) deep, spread widely throughout the area.
Floods have worsened as infrastructure has developed and reduced the landscape's soil permeability and thus its water retention capacity.
Reduced soil absorption leads not only to flooding, but also to worse water scarcity during dry seasons.
[1] Mercury, especially from gold mines along the Cauca river, is causing health issues for residents, either directly to miners or through its accumulation in fish meat.
[1] Illegal mining and deforestation increase sedimentation and pollution in the rivers, exacerbating floods and making the water more dangerous.
[1] Local communities have developed measures to promote fish sustainability, including closed seasons and gear restrictions.
This control of water flow was combined with slash-and-burn agriculture, allowing the area to support a large population.
This saw the steady selling off of formerly common land to ranchers, who benefitted from the introduction of Urochloa mutica grass and Zebu cattle.
[5]: 92 Such land disputes have increased pressure on fisheries, as those unable to farm shift to fishing year-round.
[5]: 95 Livelihoods of people in the area have historically been seasonal, reflecting the differing availability of natural resources.
[10]: 92 Plants such as Chrozophora tinctoria and Ambrosia peruviana are grown in the area, and are traditionally used as indicators of good rain.
Daily weather bulletins are distributed via radio, WhatsApp, and text messages, which some farmers use to plan their crop planting.
[1] The large amounts of water during the wet season make the region amenable to rice cultivation, which has a strong presence in nine of La Mojana's municipalities.
[6]: 51 Other crops produced include maize, sorghum, cassava, yams, sesame, sugarcane, bananas, watermelon, squash, chili pepper, eggplant, and cucumber.
