Abstract: This paper proposes a method based on sparse regularization to identify groundwater point pollution sources. Firstly，the time domain finite element discretized equation of groundwater one-dimensional convection-diffusion equation is used to obtain the frequency domain equation by Laplace transform，and then the objective function of the groundwater point pollution source identification problem constrained by the l₁norm term is established，thus overcoming the ill-posed problem of the point source identification due to sparse spatial distribution. The identification equation is then solved iteratively using the alternating optimization method. The research results show that the proposed method can effectively identify the position and intensity changes of groundwater pollution sources under noise conditions.

Key words: convection-dispersion, sparse regularization, pollution source identification, alternating optimization method, regularization parameter