Piezometric surveys in domestic wells in villages or dedicated to pastoral use, where manual measurements are made with commercial luminous probe (OTT, 100 m in length) every month for seasonal and long term mesoscale groundwater balance surveys. The water table level values are expressed from the edge of the well. A value = 9999 stands for a dry well.

Manual groundwater level for some wells and hourly groundwater measurements for others equipped with a logger. The water table level values are expressed from the soil surface.

Measurements of water level, electrical conductivity and water temperature are made by multi-level piezometers (<1m, 2m, 10m 20m depth) installed on each drilling site along specific vegetation catena (fallow, forest, bush savannah). Automatic measurements for the most superficial piezometers and manual measurements every two days for the others. The water table level values are expressed from the soil surface. A value = 9999 stands for a dry borehole.