11:15 AM - 11:30 AM
[MIS22-07] Quantitative Analyses of the Relationship between Floods and Poverty in Edo and the Process of its Overcoming
★Invited Papers
In recent years, it has become clear that disasters are a major barrier to poverty reduction. Furthermore, climate change and urbanization are expected to increase the flood risk. Although studies on the relationship between floods and poverty have been conducted in recent developing countries, the socioeconomic impacts of flood control, which require long-term analysis, have not been demonstrated. Japan, on the other hand, has a high exposure to disasters, but has been able to reduce its risks through investment in disaster risk reduction. However, even Edo, which experienced rapid urbanization and developed into the world's largest city, is said to have suffered from frequent flooding. Was there a relationship between flooding and poverty in Edo? What impact did flood control have on poverty? This study aims to quantify the relationship between floods and poverty in the Edo period and to clarify the process of overcoming since the Meiji era.
First, in order to quantify the relationship between floods and poverty in Edo, we compiled data on floods and poverty. Since there are no systematic documents on floods and poverty in Edo, we collected and digitized alternative indicators from various historical documents. Using these data, we calculated the density of the poor and the number of floods in all 21 areas of Edo, and conducted a correlation analysis. Next, for a more precise analysis, we researched the flood risk in the towns with three major slums and shacks of outcasts. The topography of each town were visualized in GIS, and this was compared with the historical background through a literature review. In the Fukagawa, Yotsuya, and Shiba areas, where flood damage occurred, we calculated the percentage of house renters in each town and analyzed the correlation with the elevation. Finally, we clarified the impact of flood control on poverty by examining flood control projects and social changes since the Meiji Era.
The results showed a positive correlation between the density of the poor and the number of floods in the entire Edo area (correlation coefficient: 0.69), indicating that the poor tend to live in areas where floods frequently occur. Next, it was found that three major slums and 25 shacks of outcasts were located along rivers, coastlines, and valley bottoms, all of which are prone to flooding. In addition, the correlation analysis between elevation and the house renting rate showed quantitatively that the poor tended to live at lower elevations in areas with large differences in elevation and flood risk within a district. Finally, it was quantitatively shown that the Arakawa discharge channel greatly improved the safety and convenience of Honjo and Fukagawa areas, which supported industrial development and improved the livelihood of the poor.
During the Edo period, due to technological and budgetary constraints, only the central part of the city was protected from flooding, and the poor were adversely affected in the peripheral areas. However, since the Meiji era, the Arakawa drainage project, which accounted for 5.5% of the national budget, has improved the safety and convenience of the former peripheral areas and promoted the improvement of the livelihood of the poor. In other words, the past governments focused on the long-term benefits of flood control, which led to the improvement of the livelihoods of the poor and the further development of the region.
The novelty of this study is that it quantified the relationship between floods and poverty in Edo on two scales and demonstrated the long-term impact of flood control on poverty by integrating indicators of floods and poverty from historical documents. This quantified relationship is the oldest in the world. This study reveals that in past Japan, the poor lived in areas at high risk of flooding, and that while flood control only in the central part of the Edo increased inequality, a long-term focus on flood control improved the livelihoods of the poor.
First, in order to quantify the relationship between floods and poverty in Edo, we compiled data on floods and poverty. Since there are no systematic documents on floods and poverty in Edo, we collected and digitized alternative indicators from various historical documents. Using these data, we calculated the density of the poor and the number of floods in all 21 areas of Edo, and conducted a correlation analysis. Next, for a more precise analysis, we researched the flood risk in the towns with three major slums and shacks of outcasts. The topography of each town were visualized in GIS, and this was compared with the historical background through a literature review. In the Fukagawa, Yotsuya, and Shiba areas, where flood damage occurred, we calculated the percentage of house renters in each town and analyzed the correlation with the elevation. Finally, we clarified the impact of flood control on poverty by examining flood control projects and social changes since the Meiji Era.
The results showed a positive correlation between the density of the poor and the number of floods in the entire Edo area (correlation coefficient: 0.69), indicating that the poor tend to live in areas where floods frequently occur. Next, it was found that three major slums and 25 shacks of outcasts were located along rivers, coastlines, and valley bottoms, all of which are prone to flooding. In addition, the correlation analysis between elevation and the house renting rate showed quantitatively that the poor tended to live at lower elevations in areas with large differences in elevation and flood risk within a district. Finally, it was quantitatively shown that the Arakawa discharge channel greatly improved the safety and convenience of Honjo and Fukagawa areas, which supported industrial development and improved the livelihood of the poor.
During the Edo period, due to technological and budgetary constraints, only the central part of the city was protected from flooding, and the poor were adversely affected in the peripheral areas. However, since the Meiji era, the Arakawa drainage project, which accounted for 5.5% of the national budget, has improved the safety and convenience of the former peripheral areas and promoted the improvement of the livelihood of the poor. In other words, the past governments focused on the long-term benefits of flood control, which led to the improvement of the livelihoods of the poor and the further development of the region.
The novelty of this study is that it quantified the relationship between floods and poverty in Edo on two scales and demonstrated the long-term impact of flood control on poverty by integrating indicators of floods and poverty from historical documents. This quantified relationship is the oldest in the world. This study reveals that in past Japan, the poor lived in areas at high risk of flooding, and that while flood control only in the central part of the Edo increased inequality, a long-term focus on flood control improved the livelihoods of the poor.