Landscapes of uncertainty: Mangrove rice farmers' perceptions of rainfall variability and climate change adaptation in three coastal regions of Guinea-Bissau, West Africa

Rainfall variability poses growing challenges to mangrove rice farming in Guinea-Bissau, threatening both local livelihoods and food security. This study investigates how farmers in the coastal regions of Cacheu, Oio, and Tombali perceive changing rainfall patterns and adapt their cropping calendars accordingly. Using a companion modelling approach, we co-designed a serious game with 45 mangrove rice farmers from 13 villages, complemented by group interviews and participant observation. The results reveal that farmers possess detailed, experience-based knowledge of rainfall variability—particularly regarding the delayed onset, mid-season dry spells, and early cessation of rains—which directly influences key agricultural decisions such as nursery establishment, transplanting, and harvesting. Through the serious game, participants collectively identified and validated four main adaptation strategies: (1) flexible adjustments to cropping systems (e.g., shifting to direct seeding in erratic years), (2) strategic use of short- and medium-cycle rice varieties, (3) enhanced water management through reinforced dykes and drainage innovations, and (4) diversification into complementary livelihood activities such as cashew cultivation and fishing. The serious game proved to be an effective tool for facilitating dialogue, sharing local knowledge, and collectively refining context-specific adaptation pathways. These findings underscore the value of integrating farmers’ ecological knowledge with participatory methodologies to support resilient agricultural planning under climate uncertainty. • Mangrove rice farmers perceive rainfall variability at the local level. • This rainfall variability has a major impact on the agricultural calendar. • These rice farmers adapt their agricultural practices using their knowledge and expertise. • As a simulation tool, serious games facilitate the collective identification of farming strategies.