Beach Planshape Modelling summarises of the theory, solution methods and applications of what has become known as the 1-line beach model whereby changes in the planform shape of a beach can be described by the movement of a single height contour. This very effectively describes shoreline response to interventions such as the construction of groynes and beach nourishment. The book covers the underlying theory; analytical solutions to the equations for restricted cases; semi-analytical methods for less restricted cases; computational methods for more general situations; applications to specific sites with a focus on ‘tricks of the trade’ to allow complicated cases to be modelled; extensions of the 1-line method to find parameters from observations; and a discussion of uncertainties in the results of predictions. It provides real-life applications and guidance to create a realistic and effective model for use, in line with the commercial GENESIS/GENCADE beach modelling package.