Geo-Pollution Science, Medical Geology and Urban Geology
Vol.2

No.2

2006

ContentsReview
37

Evolution of Disaster
Shoji FUJII

Report49

Exploitation and Tsutsugamushi disease of Niigata Plain, Northeast Japan
Takao NAKAGAWA

Letter58

Introduction of Institute for Geo-pollution Science, Medical Geology and Urban Geology -Part 2-:
Division of Sciences for Natural Environment, Faculty of Human Development, Kobe University(Tainosho Institute)
Division of Science for Natural Environment, Faculty of Human Development, Kobe University

News
62

Evolution of Disaster
Shoji FUJII
FUJII Laboratory for Environmental Geology

161-2, Anyobo, Toyama City, 930-0881 Japan

Abstract
Disaster occurs only when human society and a natural phenomenon come into contact. No severe
natural phenomena bring about disaster by themselves. When defense against one type of disaster has been
established, another unexpected form often occurs thereafter.
Disaster evolves because the human society evolves.
Although we can not avoid new types of disasters, it is possible to decrease the destruction done bydisasters by acting on information obtained from detailed, continuous studies of natural phenomena.
Following rules may be applied to the evolution in the form of the natural disasters. A new type ofdisaster occurs during the process of the recovery when man breaks the balance of nature. Similar scale ofnatural phenomena does not necessarily cause disasters. The deciding factor is the existing state of thehuman society involved.
Evolution of disaster occurs even without unusual natural phenomena but in usual natural state. A lot ofwastes induce air pollution, water pollution and geopollution.
For instance, some garbage and wastes evolve harmful materials when smoke meet with fog, somechemical compound as VOC etc. meet with bacteria in underground. Harmless material evolves harmful
material when harmful material for health is newly found in the same waste.
Some spots where garbage and industrial wastes disposed evolve contaminate areas when harmful
materials are newly found from wastes.
Keyword: Disaster, Evolution, Natural phenomena, Equilibrium, Wastes, Air pollution, Water pollution,
Geopollution

Exploitation and Tsutsugamushi disease of Niigata Plain, NortheastJapan
Takao NAKAGAWA
3-41, Sasaguchi, Niigata 950-0911, JapanAbstract
Tsutsugamushi disease (scrub typhus) conveyed by larva of Trombiculid mite (Leptotrombidium akamushi)frequently occurred in the summer along the Shinano and Agano Rivers of Niigata Plain, in Niigata Prefecture.
The mite, called “Tsutsugamushi”, inhabited only the riverside land. The history of exploitation of the plain,
which was closely connected with formation of the riverside land, is investigated, and also number of thepatients and the mortality are analyzed. The exploitation rapidly progressed during the early stage of the Edo
era (1603 to 1868), and in 1779, the area of paddies possessed by the Mizoguchis, a lord of the plain, increased
by about two times that of 1598. River improvement works were performed with progress of the exploitation,and the disease had certainly prevailed since around the Genroku period （1688 to 1704) when the riverside land
was begun to form by active construction of the embankments. The disease was also distributed along the Uono
River (a tributary of the upper Shinano River) of the Muikamachi Basin, the Mogami River in Yamagata
Prefecture and the Omono River in Akita Prefecture. The differences of the mortality suggest that the di seasecan be subdivided into three types distributed in the Shinano-Uono, Agano-Mogami and Omono River Basins.

Keyword: Niigata Plain, early Edo era, exploitation, riverside land, Tsutsugamushi disease (scrub typhus), mortality