The second TROPECOS field work in Mékong Delta, 19-26 March, 2025, involved 3 research scientists, one post doc and one master student from IGE, CARE/HCMUT and CARRTEL. The four main branches of Mékong Delta were sampled along about 500 km in order to cover the entire salinity gradient from freshwaters to seawaters along the coast. This second campaign was realised in dry season and will allow to compare different land use in the different branches (paddy rice, aquaculture, urban area…)