The simplest option would be: Create a time-varying function with these data. Then go to flow materials, use Assign - Database, Inverse distance weighting interpolation with only one neighbor, 'Edit time-varying data', type in X - Y - Number of the function for an arbitrary location in the model. Then start the interpolation. This will create a time-varying material distribution ('T-List') with this recharge distribution. The interpolation between the data points will be linear by default.