Estimated flooded areas of the Inner Niger Delta from 1960 to 2020 using the Height-Area-Volume (HAV) method

The Inner Niger Delta (DIN) is a vast wetland where socio-economic activities (agriculture, livestock breeding, fishing, navigation) are dependent on its fairly complex hydrological regime whose hydrodynamic functioning depends on river inputs from the upstream basins: the upper Niger and Bani. The flooding surface of the DIN is closely linked to its hydrological regime. It was calculated by the HAV (Height-Area-Volume) model during the study period from 1960 to 2020. The HAV model is designed on the basis of two modules: physical and hydrological. The design of the physical module resulted in the development of the HAV matrix of DIN, calculation engine of hydrological module. The hydrological module is designed on MATLAB; it calculates the variation in the volume of stored water and converts it into flooded surface area. During the study period, the maximum flood area in the DIN was estimated at 37,252 km² in 1967 compared to 8,466 km² in 1993. She is observed from mid-October until the end of December, i.e. a duration of at least three and a half months (3.5 months). The flooded area generally reaches its maximum in November in the DIN