Murasakibaru Danchi about 60 years ago and today

History of Murasakibaru Danchi

The name is read Murasakibaru. It is an area on top of a shirasu plateau projecting south of the city area of the City of Kagoshima, and this frame takes in the whole surface of that plateau in its center. Only two eras of past aerial photographs remain, but between those two the scenery on top of the plateau is replaced in one go. It is a location where the order, roads first and houses later, can be seen just by switching eras.

None of the five measuring points in the frame falls below 79 m. The highest is the west at 91.7 m and the lowest the east at 79.0 m, a spread of only 12.7 m. The center point is 81.8 m, the north 88.5 m and the south 79.6 m, so the west and north sides are high and the east and south sides low. The surface of the plateau rises gently to the northwest and falls toward the east and south. Although it is deeply carved by valleys, the numbers show that as a surface it is flat land. If you go out beyond the edge of the plateau the ground drops at once; the nearest station, Korimoto Station on the Ibusuki Makurazaki Line, is placed on the lowland below the plateau. Only the top of the plateau is flat, so to enter this area from the station you climb a slope.

Empty lots with only streets

In the monochrome 1961-69 photograph, white streets are drawn as a diagonal grid on top of the plateau. But inside the lots enclosed by the streets, square fields and empty land remain. From the center toward the east small roofs have begun to line up regularly, and within the same plateau surface the side where houses have come in and the side where they have not are split half and half. Slightly below the center there is a place where long, narrow buildings form diagonal rows, and the shape of the roofs differs from the surroundings only there. The west side of the frame is hills deeply carved by valleys, with woods and terraced fields mixed in patches, and narrow roads and small settlements can be traced on the valley floors. A city area of densely overlapping roofs lies beyond the eastern edge, and the lower right corner takes in dark sea and piers. Toward the right of the top edge a small oval ring appears, but the grain is coarse, and you cannot follow what kind of track it is.

If you look closely at how the streets are drawn, they are not made of a straight grid alone. Near the edge of the plateau the roads curve gently with the terrain, and the lots are distorted into triangles and trapezoids too. Where the heads of valleys cut in, the lots break off, and the streets go around them. This means the allocation, lining up lots only on the flat ridges and leaving the carved valleys untouched, had already been decided before the houses came in. The size of a single lot is clearly larger when set beside the rows of roofs densely overlapping in the city area to the east. The shape shows that a large surface was divided in one go rather than the original city area being extended little by little.

A plateau surface lined with buildings

If you switch to the 1974-78 color photograph, the empty lots are filled with houses. Within about ten years the white framework of streets has become a residential area as it is, and the shape of the streets does not change across the eras. The wide curved road running diagonally through the center is in the same position in this era too, and rows of long, narrow buildings line up on both sides of it. The buildings are an order of magnitude larger than detached houses and can be told apart from their surroundings by the size of their roofs. Slightly above the center, a little toward the left, there is a brown surface that looks like a sports ground, with a section where long, narrow buildings stand beside it. Several facilities that look like schools are placed on top of the plateau. The valleys to the west remain woods and terraced fields. In the southwest corner, in a place that had been only valleys and slopes until then, large white buildings appear together, with brown bare ground and white cut slopes spreading around them.

Grown trees and remaining valleys

In the latest aerial photograph, the top of the plateau is packed with roofs without gaps, and trees grown along the streets cast dark shadows. In some of the places where long, narrow buildings lined up in 1974-78, rows of large gray buildings sit facing the same direction. This means the layout was carried over even when they were rebuilt. The surface of the sports ground that was brown and the section with buildings with light-blue roofs are found in the same places as they were. The valleys carving the plateau are interesting: although surrounded by city area on all sides, only the valley lines remain green. Places where the slopes were steep and hard to build on have remained as woods. The southwest corner is also filled with housing and facilities, and the bare ground seen in 1974-78 is nowhere to be found. Outside the plateau, the piers facing the sea at the lower right have increased in number, and the shape of the shore bends finely.

There are three markers for going back and forth between eras. One is the wide curved road running diagonally through the center: as a white band without houses in 1961-69, as a street between rows of buildings in 1974-78 and as a street edged with trees in the latest photograph, the same single road appears in three different forms. The second is the valleys to the west, where the outline of the woods hardly moves across the three eras. The third is the surface that looks like a sports ground slightly above the center, which has not moved from the position where it appeared as brown ground. If you look at what changed and what did not change separately, it becomes easier to grasp what was replaced on top of the plateau.

Land values can be traced at one point in a residential area of Murasakibaru 4-chome, only about 130 m from the center of the frame. The record begins at 145,000 yen per square meter in 1993, and the highest up to the 2026 official land prices (Chika Koji) is 154,000 yen from 1998 to 2001. From there it turned downward, and the lowest up to the 2026 publication is 115,000 yen from 2015 to 2022, and 120,000 yen in 2025. In the 2026 publication it is 122,000 yen. Through the thirty-odd years up to the 2026 publication, it is a series with small swings, in which the difference between the highest value of 154,000 yen in 1998-2001 and the lowest value of 115,000 yen in 2015-2022 stays within 39,000 yen. As a residential area on top of a plateau, the small movement of its value shows directly in the record.

Shirasu is a pyroclastic flow deposit widely distributed in southern Kyushu; it is easy to dig and easy to make into flat surfaces, but it has the property of collapsing easily when it holds water. As can be seen in the aerial photographs, the edges and valley lines of this plateau are steep slopes. The City of Kagoshima's disaster maps show, as area shapes, which parts of the slopes along the cliff lines fall within the areas assumed for landslides. If you open the maps after confirming the positions of the valleys in the photographs, it is easier to read what the lines of the areas follow.

A comparison of a residential area opened on a hill can also be made at Otokoyama Danchi.