  We present transport measurements in a quasi-1D system of surface electrons
on liquid helium confined in a 101-$\mu$m long and 5-$\mu$m wide microchannel
where an electrostatic potential with periodicity of $1$-$\mu$m along the
channel is introduced. In particular, we investigate the influence of such a
potential on the nonlinear transport of quasi-1D Wigner Solid (WS) by varying
the amplitude of the periodic potential in a wide range. At zero and small
values of amplitude, quasi-1D WS in microchannel shows expected features such
as the Bragg-Cherenkov scattering of ripplons and reentrant melting. As the
amplitude of potential increases, the above features are strongly suppressed.
This behavior suggests loss of the long-range positional order in the electron
system, which is reminiscent of the re-entrant melting behaviour due to the
lateral confinement of WS in the channel.
