Background: A study was conducted on the processes of formation of hydromorphic soils in the estuary plateau region of Andem, Gabon, Africa through determination of hydromorphic index (HI), particle distribution-ratios and CEC/clay using details soil survey database followed by their appropriate classification in USDA soil taxonomy.&nbsp; 
 
Methods: The experiment carried out at Andem estuary region during 2022-23. The findings indicated that the surface horizons of these soils appeared wet with a reddish-brown coloration, accompanied by the presence of iron (Fe2+) and manganese (Mn2+) nodules in reduction phases at depths ranging from 25 to 60 cm. Additionally, redoximorphic depletions were observed below 60 cm in soils located in lower piedmonts and older alluvial plains.&nbsp; 
 
Result: These indices show a significant relation with the physicochemical properties of the soil. Furthermore, it was observed that these soils tended to accumulate organic matter at a rate surpassing its decomposition. The results also demonstrated a variation in Hydrologic Index (HI), ranging from 11.8 in Humic Endoaquepts to 5.2 in Typic Udifluvents, these criteria utilized for confirming and establishing hydromorphic soils could provide valuable insights for managing these soils to enhance productivity and optimize land use practices.

Unveiling Hydromorphic Soil Formation Dynamics in Andem, Gabon: A Soil Survey Approach