55: Recovery of River Levee

4/16 Widened the road to 2 lanes

To prevent or mitigate sediment disasters during snow-melting or rainy seasons, MLIT carried out urgent checkups of locations with risk of sediment disaster, and promoted temporary recovery and continuous monitoring of those risky places in the municipalities that experienced more than 5 upper of seismic intensity. $ ^{1} $ MLIT also launched urgent development of sediment control levees in the areas affected by the earthquake and has promoted the development of levees in the places where landslides might happen until typhoon season. Furthermore, meteorological observatories and prefectural governments have worked together on early evacuations by lowering the risk level at which sediment disaster warnings are to be announced.

Based on the result of these urgent checkups, for the areas where sediment disaster is highly likely to happen during rain, MLIT will consider systematic measures against sediment disaster in terms of both physical infrastructures (hard policies) and intangible measures (soft policies), in cooperation with prefectural governments. It also promotes measures against sediment disaster in the affected areas, in accordance with the initiatives to rebuild afflicted cities.

Emergency Response and Recovery of Transportation Infrastructure and the Securing of Emergency Routes for Transportation and Logistics

Once traffic infrastructure is cut off, immediate response to disaster (including rescue efforts) is greatly impeded. Accordingly, temporary restoration of transportation infrastructure leading to the afflicted area was the first priority. MLIT made all the efforts to secure emergency routes for transportation and logistics on land, by sea, and by air as soon as possible in order to connect the isolated affected areas extending along the Pacific coast damaged by the huge tsunami.

Quakeproof measures which had been taken prior to the earthquake prevented serious damages and led to early recovery of transportation infrastructures. For instance, bridge footings on highways had been made quakeproof and the Shinkansen railways had recently been equipped with automatic stopping systems that detect quakes early. These measures had been taken based on lessons from the Hanshin-Awaji Earthquake with the damage to elevated bridges due to footing collapse on the Hanshin Expressway and the damage to more than 700 bridge footings of Shinkansen railways, and on lessons from the Mid-Niigata Earthquake with the derailment of operating Shinkansen trains. Thanks to these measures, elevated bridges on expressways and the Shinkansen railways were not seriously damaged, allowing for early recovery of those infrastructures.

Sendai Airport was immune to liquefaction, and kept the flatness and pavement strength of its runways thanks to quake resistance, which in turn led to early recovery.

On the other hand, transportation infrastructures such as residential roads and local railways, the lifelines supporting local transportation and preventing settlement isolation, have been suffering extreme difficulties in reconstruction works because they were greatly damaged, especially by the huge tsunami. This disaster, having been beyond expectation, has caused serious negative influences on reconstruction works. For example, Sendai Airport had not promoted measures against such a huge tsunami, such as how to manage drifted debris and inundated emergency power generation facilities. Also, in ports around the afflicted areas, destruction of their facilities by outstanding pressures from the massive tsunami, and impeding drifting objects such as immense amount of debris, vessels sunk within ports, and fishing nets, have serious impact on recovery.