Japan Geography Quiz | Reading Chūbu Rivers, Basins, Peninsulas, and Bays, Set 4

The Echigo Plain spreads through the basins of the Shinano and Agano rivers in Niigata on the Sea of Japan side. The Shōnai Plain is in Yamagata, while the Tone River flows across the Kantō Plain, so both the plain and its river basins must match.

On Sado Island, the Ōsado Mountains run in the north and the Kosado Mountains in the south, with the Kuninaka Plain in the central area between them. The Echigo or Niigata Plain is on the Honshū side, not between Sado's two mountain areas.

Toyama has the Tateyama Range to the east, mountains continuing from the Hida Mountains to the south, and Toyama Bay to the north. Alluvial fans built by rivers flowing out of these mountains shape the Toyama Plain, so marine erosion or lava is not its main origin.

Coastal terraces are developed along Sotoura, where erosion by open-sea waves is conspicuous. Uchiura, by contrast, has a submergent, indented, comparatively calm coastline. The distinction follows the environmental difference between the outer coast and the bay-facing inner coast.

A ridge linking the Yamanaka, Kinome, and Tochinoki passes divides Fukui into Reihoku in the northeast and Reinan in the southwest. The ria coast formed by the subsidence of Wakasa Bay lies on the Reinan side, so the directions of Reihoku and Reinan must not be reversed.

The conditions identify Yamanashi Prefecture, whose central lowland is the Kōfu Basin. Yamanashi is surrounded by high terrain including the Kantō and Akaishi mountains, the Misaka Mountains, and Mount Fuji. The other basins exist, but their surrounding mountain configurations do not match the question.

The Tenryū and Kiso rivers flow south toward the Pacific side. The Chikuma and Sai merge and, near the Niigata border, become the Shinano River, which flows north to the Sea of Japan. Rivers from a landlocked prefecture do not necessarily all drain to the same sea.

Northern Gifu's Hida region contains peaks over 3,000 meters, including Mount Norikura and Mount Okuhotaka. In the southern Mino region, the Kiso, Nagara, and Ibi—the Kiso Three Rivers—flow across the Nōbi Plain. The expression Hizan Nōsui, “Hida's mountains and Mino's waters,” reflects this contrast.

One branch becomes the Nagara River and heads toward the Pacific side, while the other becomes the Shō River and heads toward the Sea of Japan. Even water falling in nearby places can ultimately reach different seas depending on which side of the watershed it enters.

The mouth of Suruga Bay runs between Cape Irō at the southern end of the Izu Peninsula and Cape Omaezaki to the west. Cape Inubō and Cape Nojima are in Chiba, Cape Ōma and Cape Tappi in Aomori, and Cape Muroto and Cape Ashizuri in Kōchi, so none of those pairs encloses Suruga Bay.