Hydrological extremes and food security in western Amazon

International audienceThe water level of the Amazon and of its tributaries varies significantly from one season to another. For instance, at Iquitos station (Peru), the water level varies from 18 meters in May-June to 8 meters in September-October. That is why, during the low-flow period, cultivating becomes possible and is important on the riverbanks and in the inundation plains. Agricultural production in a family-based system on the riverbanks and inundation plains is very important in terms of guarantee of supply for food security. In order to understand the important relation between agriculture, food security and hydrological system some characteristics of the local agriculture in the Amazonian region located between Iquitos (Peru) and the triple frontier between Brazil, Peru and Colombia are first presented using results from field observations, survey and data from the Peruvian and Brazilian Agricultural agencies. Then, information about the interannual variability (1980-2014) of the hydrological cycle of the Solimões River are presented: discussion and definition of the dates of the beginning and of the end of the low-flow period, duration of the low flow period, velocity of the water level changes during the increasing and decreasing flow periods, presence of “false alarm” at the beginning or at the end of the dry and the wet period, … This part is developed using water level data from the national hydrological services of Peru and Brazil and from the Environmental Research Observatory SOHYBAM (Geodynamical, hydrological and biogeochemical control of erosion/alteration and material transport in the Amazon basin). Finally, as a shorter than usual length of the low flow season, a rapid increase of the water level, a “false” beginning of the low water season, etc. are hazards that may put at risk sowing and plant development, hydrological parameters are related to yield values seeking possible correlations between extreme events and food security in the region