Local existence of classical solution to the chemotaxis-shallow water system with vacuum in ${\mathbb{R}}^2$

In this paper, we consider the chemotaxis-shallow water system in ${\mathbb{R}}^2$. We establish the local existence of classical solution without assuming the initial height is small or has a small perturbation near a constant. The far field behavior of the height is a constant which could be either vacuum or non-vacuum. The initial data is allowed vacuum and the spatial measure of the set of vacuum can be arbitrarily large.