  Aims. Accretion and luminosity bursts triggered by three distinct mechanisms:
the magnetorotational instability in the inner disk regions, clump infall in
gravitationally fragmented disks and close encounters with an intruder star,
were studied to determine the disk kinematic characteristics that can help to
distinguish between these burst mechanisms. Methods. Numerical hydrodynamics
simulations in the thin-disk limit were employed to model the bursts in disk
environments that are expected for each burst mechanism. Results. We found that
the circumstellar disks featuring accretion bursts can bear kinematic features
that are distinct for different burst mechanisms, which can be useful when
identifying the burst origin. The disks in the stellar encounter and
clump-infall models are characterized by tens of percent deviations from the
Keplerian rotation, whie the disks in the MRI models are characterized only a
few percent deviation, which is mostly caused by the gravitational instability
that fuels the MRI bursts. Velocity channel maps also show distinct kinks and
wiggles, which are caused by gas disk flows that are peculiar to each
considered burst mechanism. The deviations of velocity channels in the
burst-hosting disks from a symmetric pattern typical of Keplerian disks are
strongest for the clump-infall and collision models, and carry individual
features that may be useful for the identification of the corresponding burst
mechanism. The considered burst mechanisms produce a variety of light curves
with the burst amplitudes varying in the \Delta m=2.5-3.7 limits, except for
the clump-infall model where \Delta m can reach 5.4, although the derived
numbers may be affected by a small sample and boundary conditions. Conclusions.
Burst triggering mechanisms are associated with distinct kinematic features in
the burst-hosting disks that may be used for their identification. Abridged.
