Modern-style Map of a Fictional Region AI Image Prompt

In the style, pattern, and composition of a modern map, draw a map of a region that does not exist in reality. The basic terrain and landform of the region are as follows: the main part is a horizontally placed, slightly rectangular large lake; in the center of the lake is a roughly square large island, with a highest peak at the center of the island; at the four corners of the lake, several larger rivers flow in, and along the east, west, south, and north shores, several smaller rivers flow in; at the mouths of the larger rivers there are port cities; the north shore is relatively flat with a few hills, the east shore is mainly plains, the south shore has low flat land in the eastern half and mountains in the western half, and the west shore has generally higher terrain with large marshes and mudflats. Imitate the texture of paper printing, with exquisite modeling and fine texture.