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In this talk I will present some results obtained in the context of a point vortex description of a flow.It has been known for a long time that point vortices correspond to an exact(in the weak sense)solution of the Euler or Helmoltz equation,as long as the vortices follow some prescribed Hamiltonian dynamics [1].In certain configurations the motion of vortices can lead to a finite time singularity,as for instance three point vortex collapse.In the first part of the talk,we shall discuss the different type of motions that can arise in close to collapse configuration [2].Then we shall see how we can eventually use the singularity to generate large distribution of vortices,and infer some information on these distributions[3].Finally we shall consider an ad hoc model of wave-vortex interaction,and display as well that the merging of two point vortices can occur.And show that this model may be able to predict the behavior of wave-vortex interaction in the context of the Charney-Hasegawa-Mima equation,describing identically two-dimensional geophysical flows or two-dimensional plasma turbulence in a tokamak[4].