Final answer:
The Drava River is the river that forms the border between Hungary and Croatia. It is an important waterway in Eastern Europe that eventually merges with the Danube River.
Step-by-step explanation:
The river that flows along the Hungary-Croatia border is the Drava River. The Drava is a significant river in Eastern Europe and plays a crucial role in the biodiversity and aquatic systems in the regions it traverses.
Its catchment area is part of the larger Danube basin. It originates in Italy, flows through Slovenia, forms the border between Croatia and Hungary, and eventually joins the Danube River.
The Drava originates in Italy, flows through Austria and Slovenia, forming parts of borders between Croatia and Hungary, and finally merges with the Danube near Osijek in Croatia.
Rivers like the Drava have historically been important for transport and trade in Europe. However, they also serve as corridors for invasive species, which can travel via the natural flow of the river or by hitchhiking on vessels.