The purpose of this study is to identify the characteristics of spatial structures of Okura-syo owned by Yanagawa Domain in the Edo period. Yanagawa Domain had one Okura-syo to provide salary to their warriors and three Okura-syo to stock rice for transportation. The domain faced the Sea of Ariake, which has the largest tidal flats in Japan. Under the natural conditions where irrigation water tended to run short, the villagers maintained their life with their water use practice.
Previous researches and the procedure of this study are shown.
First, actual spatial structures (enclosure of the site, type of building arrangement, Okura's room layout, lean-to, and appearance) were shown by Okura-syo. The Okura-syo consisted of Okura and offices. Next, looking at the rooms in each Okura, some rooms were most size and others had larger floor area. The former is called a most-sized room, and the room with largest floor area a large room. Lastly, we looked at other facilities. In Yanagawa Domain, there was no sign of inspection station or guard house.
What the spatial structures of these four Okura-syo have in common and how they are different are shown, and types of building arrangement, pattern of spatial formation, and their factors are discussed. First, two types are distinguished by enclosure of the site: Type 1, moated with no actual fence, and Type 2, no moat and with fence around it. For Type 1, yarai fence connected between buildings, and the yarai fence and buildings all served as a fence for the garden. A possible factor for Type 1 is the officers enclosing the people and stuff. Secondly, no type of building arrangement was observed other than for Tamachi Okura-syo. In Type 1, however, the rooms tended to be arranged in a string, with large rooms close to the entrance, most-sized rooms back in the building. Yanagawa Domain put a priority on storing things in Okura in the order of the delivery date of an agricultural tax. In other words, it is assumed that they intended to make the storing system easy and smooth for carrying in an agricultural tax. Thirdly, we reviewed Okura. In Yanagawa Domain, barley, soybean, and mustard were also stored in Okura-syo as an agricultural tax. A primary agricultural tax was rice, and it was assumed that most-sized rooms, which took up the majority, were used to keep rice paid in autumn. On the other hand, barley, soybean, and mustard were paid in summer. It was pointed out that one possible reason why Okura had both most-sized rooms and large rooms is because each room stored different things and the timing when the things were carried in was also different. It was also cited that the reason why no space was formed in front of the door was because there was busy traffic of ships taking advantage of the biggest tidal difference in Japan, which made it unnecessary to have a temporary stock space for rice to be transported, and also there was an office where the officers were present.
It was concluded that the Okura-syo owned by Yanagawa Domain, in the geographical conditions along the Sea of Ariake at that time, became to have characteristic spatial structures out of consideration to the people and their carrying in smoothly.