4.Research on Human-Oriented Disasters in Coastal Zones

Background and Objectives

Occurrence of an oil spill disaster makes widespread　devastating damage inevitable as shown by the Nakhodka　tanker accident. Furthermore, recovery efforts mainly　depending on human power take extremely a longer time so　that immediate recovery operations are highly demanded.　Oil spill from a vessel and mixture with seawater causes its　viscosity and specific density exponentially increase, and　therefore vacuum suction needs enormous energy. In this　way, it is difficult to transport spilled oil smoothly since it　adheres firmly to the inside of pipes. To separate oil from
contaminated seawater is quite difficult and takes a longer　time to dispose of after recovery. Due to all the reasons　mentioned above, it is hard to say effective countermeasures　for oil recoveries have been established.
Meanwhile, there has been an increased demand for　human-caused disaster measures including counterterrorism　measures to ensure security since the terrorist attacks in　the United States on September 11, 2001. In accordance　with safety demands, though improvements in security at
ports and harbors have been developed, counterterrorism　measures under the sea lag behind land-based or oceansurface　measures.
In this research theme,Oil spill response R&D activities　include:
-Development of high performance oil recovery devices such　as a high-viscosity oil skimmer using steam-driven jet pump
-Oil spill drift forecast for effective oil recovery vessel　operation
We have also worked with studies on developing　technologies that would enable imaging of objects under the　sea where optical cameras cannot be used due to turbidity.

Research topics

Due to the mixing with seawater, spilled oil from vessels becomes extremely highly viscous, which causes an impediment to recovery work. Thus, we have developed various equipments to automatically recover an oil slick, and will work on improving its efficiency in the future. Meantime, physicochemical methods of reducing viscosity are effective for oil disposal after recovery, so that we will continue to work on this matter. We will develop highly efficient vessel-based oil recovery equipment to adapt to the characteristics of the operating areas as well as to the MLIT vessels for environmental improvement. In order to contribute to efficient oil recovery, we will advance oil slick drift prediction technologies to keep tracking oil spills.
On the other hand, to improve security under the seawater where it is hard to discern with optical cameras, we will work on a development of detection technologies for unidentified objects under the sea such as acoustic technologies, which make it possible to image an unidentified small submarine.

Activities in FY 2010

The following activities are held regarding measures for oil spills on the ocean surface.
We have implemented the following activities for countermeasures against oil spills on the ocean surface.

1. Since FY 2009, we have continued to develop oil spill recovery equipment with an added dispersion method made for the oil recovery vessel Harima, owned by the Kinki Regional Bureau of MLIT.
2. On April 20, 2010 when Deepwater Horizon, a semisubmerged oil drilling rig, exploded in the ocean, a huge amount of oil from the oil well gushed into the Gulf of Mexico and resulted in serious consequences on the Gulf as well as the coast. We sent our senior officers and researchers there to conduct a field investigation on the situation and to consider countermeasures against the damage.

   Left:Oil recovery work at the incident site	Right:Oil spill at the mouth of the Mississippi River
   Investigation of the oil spill in the Gulf of Mexico (between July 11 and 18, 2010)

3. As to a real time tracking oil spill device, we have improved automatic tracking buoys for oil spill drifting developed in the past years, and conducted field experiments offshore of Hiratsuka, Kanagawa Prefecture by collecting and sending information on marine phenomena on the sea
   surface, tracking artificial oil, and drifting a standard and the improved buoys and comparing their statuses.
4. In order to improve the accuracy of the predictive simulation of oil spill drifts, we have established a basic model applicable for closed marine environments such as Tokyo Bay, and verified a drifting force due to wind force using a large scale test tank.

We conducted the following activities related to port security.

1. We developed software for a device for capturing images and supporting measurements in turbid water. The software can analyze three dimensional data of the underwater portion of a structure using the measurement data and the correction sensor data (such as RTK-GPS, GPS-compass, and Clinometer) output by the device to display the geological data in synchronization with the real time map information. We conducted a sea experiment at the construction site of D-runway at Tokyo International Airport (Haneda Airport) to verify and evaluate the operation of the device and software. We also created an operation manual to implement the device.