Taichung City is one of the cities carried out Urban Rectification during Japanese Governance, whose urban development sprouted from Japan-ruled period. After the Restoration, 1945, a large number of population flooded into the cities, and the population of Taichung grew rapidly, which caused the shortage of the existing urban space. Hence, the new metropolis plan was brought into force in Taichung city. Rivers distribute over Taichung city, and the river lines were deeply affected by the urban development. Since the Japanese governance period, the course-changing constructions were applied to Green River and Liu Chuan. Under the urban development, people started to gather in cities. Taichung government, in order to safeguard the asset and lives of citizens, proceeded to manage several rivers: diked the rivers, full and cut down the original routes, which changed the river basin accordingly.
This study from Japan-ruled period to the modern urban period , which investigates urban development policies and the change in the internal structure of Taichung City to understand Taichung City''s urban development context, and which uses population, industry and cultivated field change data to explore the process of urban development. Because of the age of Taichung urban development background and colonial policy formation in central Taichung, Taichung City became the political and economic center. And Japan-ruled period Taichung City developed Secondary and Tertiary industrial sectors, but the industry was subject to colonial policies, mainly for the food processing industry and other light industries. After the Retrocession, the economic policies is foster industry through agriculture, because the area of Taichung City to expand, the industrial structural changed. At the beginning of the Restoration, the highest was Tertiary industrial sectors, then Primary industrial sectors, followed by the last of Secondary industrial sectors. Until the 1970s the government began promoting industrial policy, Taichung industrial structure changed again, and Taichung City became industrial and business urban. The industrial structure changed resulting reduction of cultivated field, and the agricultural land use changed to urban planning, and the urban river functions changed to drainage function, because of the reasons, the river basin of Taichung City changed.
In this study, the use of the map data from different years for different periods of the river basin overlay analysis, and found the river basin space in Taichung City transformation is along with the urban development and the river functional changes. The highly urbanization of Taichung City leads to the impervious surface increasing, and Taichung river basin transformed urbanization-river. When the river basins stress the drainage function, then the rivers become the regional drainage and artificial ditches.
According to the study, the result is the river basin in space without too obvious changes. The change is the use of human society on the river way. When the agricultural society into urban society, resulting from the functioning of river livelihood and agricultural irrigation use into a drainage function, and rivers originated from the city''s role in urban development into the hamper, to promote the development of urban, the river improvements are towards to artificial channels.
Modern people began to notice ecology and sustainable development, while in the past the lack of humanistic perspective in river basin improvements. In the future, the engineering river improvements should integration of humanistic thinking to facilitate the coexistence the urban and the river basin.