River and basin management covers
various factors, including disaster management, river water
use, and conservation of the river environment. Any of these
factors involves a number of intricately intertwined
stakeholders who may have different needs. Over time,
efforts to manage water-related disasters in Japan have led
to the concept of integrated river basin management and to a
mechanism allowing central management of river basins by
river management authorities. These attempts to promote more
advanced integrated management of river basins have provided
the foundation of social and economic development in Japan
today. The collected hydrological data and forecast
information are used by river management authorities
themselves and also delivered to municipalities, fire and
police authorities, and the Self-Defense Forces in an effort
to prevent disasters from occurring, assist residents in
evacuating safely, and provide emergency response quickly.
At present, hydrological information is used for operating
and managing structures such as dams and water gates,
monitoring unusual events during floods, and forecasting
inundation. This is widely shared by local governments,
which make decisions on evacuation orders and advisories;
organizations that support disaster management efforts of
local governments; government headquarters for disaster
control, which are activated in case of large-scale
disasters; organizations that operate lifeline utilities
(e.g., electric power, gas) and traffic infrastructure
(e.g., expressway, railway); and mass media.