A partial differential equation (PDE) is proposed for simulating the lake drying-up. Precisely, we were interested in the change of the water level of Lake Chad in long-time. A couple of least squares and Donor-cell scheme are used to identify both the level and unknown parameters in a lake model. Numerical experiments give the behaviors of lake level and the values unknown parameters of model.

lake drying-up, Donor-cell scheme, least squares, lake level, satellite image.