産業革命前における水力産業都市・桐生の形成

 Around 1860-1890, when there was almost no fossil energy nor electric power, a city in Gunma Prefecture, Kiryu, Japan developed itself into an extraordinary city of silk textile industries with a highly specialized urban zone structure to maximize production by harnessing their water resources for industrial power sources.<br> Kiryu is located in-between two rivers, Watarase-River and Kiryu-River. Watarase-River runs through the southwest part of Kiryu and Kiryu-River, much smaller than Watarase-River, runs the northeast part of Kiryu, joining the former in its downstream. Two channels were developed to run through Kiryu already before the preindustrial revolution period. One was Ozeki-Channel irrigated from Kiryu-River running through the old city center and the other was Akaiwa-Channel irrigated from Watarase-River running through the west periphery of the old city. However, by now, the most part of the two channels except for some part of Akaiwa-Channel was covered to closed conduits.<br> We charted out the channel map for the preindustrial revolution period around 1869, and compared the geographical distribution of the two channels with the distribution of textile industries' waterwheels to make clear that the urban zone structure specialized for each division of the textile industries was developed based on water-power along the two channels.<br> Just about the same number of yarn twisting waterwheels was existing around both channels. However, hard yarn twisting with waterwheels, dyeing and weaving were concentrated around only Ozeki-Channel. Since hard yarn twisting, dyeing and weaving were for expensive textile products, those expensive textile productions are supposed to have been performed in the closest area to the city center, Kiryu-Shinmachi, around Ozeki-Channel. This coincides with the fact that the area was the home of Kiryu's industrial leaders since Tokugawa-Government established Kiryu-Shinmachi in 1591 (the early Edo period). Today, although few people recognize Ozeki-Channel, it was once utilized much more heavily than Akaiwa-Channel was.<br> The utilization of Akaiwa-Channel increased after the Meiji Reform of 1868 because they needed the larger water-power to produce mass-productions for export.<br> Indeed, Akaiwa-Channel area had a much larger potential of expansion than Ozeki-Channel area since water of Akaiwa-Channel was directly supplied from Watarase-River which is much larger than Kiryu-River. Later, in 1887 Nippon-Textile Corporation, the biggest commercial modern factory of that time, was established near Akaiwa-Channel and started modern water-power generation, as the first water-power generation in Gunma Prefecture.<br> Although, people in Kiryu today do not know the fact that Kiryu was a textile industrial city developed with harnessing water-power massively in the preindustrial revolution period, Kiryu at that time deserves the name of "water-powered industrial city".<br> To construct a scenario for local cities and towns to harness their natural energy resources is becoming more important today for the sustainable future. Revisiting historical processes of local cities, like Kiryu, to see how they harnessed natural energy resources for its development before fossil energy and electric power became popular should give us some important hints for the design of sustainable cities.