Multimodal transportation accessibility of açaí to consumer markets in the lower Tocantins Basin in the Brazilian Amazon

Acai is a highly perishable fruit and historically a key component of Amazonian diets. From a decolonial perspective, açaí is a territorial and cultural cornerstone of Indigenous and riverside communities whose livelihoods depend on efficient access to markets. This study analyzes seasonal accessibility using three indices: two based on the available transportation network and one incorporating land use and land cover classifications. Potential routes were estimated between 103 production sites and nine commercial destinations in Mocajuba and Cametá, in both dry and wet seasons. Our methodology creates a very flexible approach for complex river systems that can be used to calculate river distances in an adaptive and efficient manner and that can be used in other regions of the world where rural communities must rely on rivers for transportation. Travel speed measures were weighted based on the channel hierarchy in the Lower Tocantins River basin, and were obtained through field measurements conducted via boat and car surveys by the National Institute for Space Research (INPE). To ensure the models remained effective, 23 field questionnaires were applied to better establish the parameters of transportation, logistics, and travel time between origin and destination. A multimodal transportation network framework was analyzed, integrating river and terrestrial routes. Additionally, an origin-destination matrix was generated along with the route's accessibility maps and graphs. The results highlighted Mocajuba's market with the highest accessibility index and Cametá's market with the lowest. The study ranks all 103 production sites (origin) according to their transportation accessibility across the accessibility methods.