Influence of Microtopography and Alluvial Lowland Characteristics on Location and Development of Residential Areas in the Kuji River Basin of Japan

Rei Itsukushima,Kazuaki Ohtsuki,Tatsuro Sato

doi:10.3390/su12010065

Abstract

Adopting a comprehensive, basin-wide method for preventing flood disasters would be effective to deflect the climate-change-induced intensified water-related disasters. This study considers the land use and settlement patterns based on microtopography and flood risks. The influence of the microtopography and alluvial lowland characteristics on the location and development of residential areas in the Kuji River basin, Japan, is a fundamental aspect of historical knowledge. Investigating the relation between the microtopography and the location of antiquities shows that most of the relics dating to or before the third century were situated in the terraces near the lowlands. The development of lowlands near the mainstream of the Kuji River began around the third century. Furthermore, the relation between the microtopography and development of residential areas is investigated using building density as the development indicator. The results confirm the increase in building density in the alluvial surface, proving a history of flood damage and delayed development compared to other regions. This investigation reveals land development in areas, including the former river bed on the mouth of the Kuji River and the flood plain on the margins of the Hitachiota urban distinct, with no confirmed inhabitation before modern times because of elevated flooding risk.

Highlights

Floods are among the most severe disasters and cause much human damage and economic loss globally [1,2]
The knowledge reveals the relationship between human society and inundation risk, and this knowledge will contribute to large-scale flood countermeasures from the perspective of appropriate land use or relocation to areas with lower risk of flood inundation
1) The alluvial lowland (AL) of the Kuji river was classified into alluvial surface (AS) Ib, which formed as a delta and meandering channel with many former river channels, AS Ia, which comprises river-flood and wetland sediments, located on AS II where the inundation risk is high

Summary

Introduction

Floods are among the most severe disasters and cause much human damage and economic loss globally [1,2]. Many of the deaths due to flood disasters are concentrated in developing countries such as India, China, and Bangladesh [7]. Economic loss is serious in the developed countries where flood prevention systems have been progressed. The annual average flood damage in Europe in the last few decades is about EUR 4 billion per year [8]. An economic loss of $ 9.256 billion occurred from 1972 to 2006 due to 531 severe floods in the United States [9]

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Conclusion