  The quasi-integrable KdV equation has been obtained from the corresponding
deformation of the Hamiltonian for the usual KdV system. Following suitable
gauge-fixing, it has been found that the quasi-conservation condition is
satisfied and an infinite number of anomalous conservation laws are obtained,
with some containing possible conserved charges. Judicious choice of
deformation of the Hamiltonian clearly leads to a conserved charge, manifesting
quasi-integrability, but also creates a hierarchy of higher-derivative
equations with at least one conserved charge. A particular quasi-deformation
parameterization of the Hamiltonian is found to complement the same of the NLS
system, following an approximate equivalence of the two systems obtained
earlier, in the weak coupling limit. Single-soliton solutions for all these
cases are obtained, with manifest scaling due to the quasi-integrable
deformation. Finally, quasi-conservation formulation for the complex coupled
generalized KdV system is obtained.
