Typical mountainous terrain west of the city of Morioka in northern Honshu. -- Japan's location, along a boundary where earth crustal plates are converging, is largely responsible for the Japanese landscape. This convergence both pushes up the land surface producing mountains (at the same time causing earthquakes) and generates the volcanic activity characteristic of much of Japan. The result is that most of Japan consists of hills and mountains. The interplay between rapid uplift and rapid erosion by fast moving streams produces a landscape of steep slopes and narrow ridges and valleys. -- This is a typical mountainous landscape. Note the absence of any significant flat floodplain in the valley bottom.
Flat land used for new suburbs west of Morioka. -- This illustrates how a burgeoning population and demand for housing leads to suburban sprawl onto available flat land. The ridges remain forested while the flat alluvial plain is occupied by new homes. Previously this was agricultural land.