Norio Maki

Rehabilitation of Urban Settlements in the Early Reconstruction Stage after a Tsunami –A Case Study of Banda Aceh Municipality in Indonesia–

Abstract This paper aims to analyze the rehabilitation process in Banda Aceh after the tsunami, focusing on the housing supply as of August 2005. The paper also reveals a community–based approach in a settlement named Deah Glumpang. The main findings are outlined as follows. The basic process of the rehabilitation of urban settlements consists of the following four steps. i) confirmation of the survivors, ii) confirmation of the boundary between plots and making of maps (PS), iii) land consolidation (LC) and iv) supply of permanent houses. There were two organizations active in the rehabilitation process. UN–Habitat adopted a community–based approach. ADB adopted a comprehensive approach to rehabilitate the settlement by drawing up a master plan to reconstruct the infrastructure and surrounding environment prior to housing supply. The initial permanent housing model led to a mismatch between the proposal and the actual needs, especially in the inner–city situations where people were hoping to obtain houses with better conditions.

International collaboration for the early damaged area estimation system using DMSP/OLS nighttime images

In the Hanshin-Awaji earthquake disaster, the lack of information about where the earthquake damaged areas were prevented early and effective emergency responses and relief. Since then, the national and some local governments in Japan have developed GIS-based damage estimation systems, but few other countries have such systems as yet. Nighttime city lights decreased significantly after a large earthquake, and the DMSP/OLS imagery is suitable for the early estimation of the damaged areas. The damaged areas of the 1999 Kocaeli earthquake in Turkey and 1999 Ji-Ji earthquake in Taiwan were estimated by using DMSP, and the results showed a good match with the real reported damage. We propose a new program through international collaboration to support emergency response and relief activities by providing information as to the estimated impacted areas within the first 24 hours after any significant earthquake. This program consists of the following steps: (1) acquire the earthquake hypocenter data through the Internet, which is for example announced by the USGS. (2) Determine the sampled area of the images by the attenuation formula of earthquake ground motion. (3) Obtain corresponding both time-wise and area-wise DMSP/OLS nighttime images from NOAA/NGDC. (4) Estimate the damaged areas by analyzing the statistically significant decrease in the light intensity of the images. (5) Create a thematic map to present the estimation results as geographic information. (6) Disseminate the resulting map widely and quickly through the WWW.

Disaster resilience and population ageing: the 1995 Kobe and 2004 Chuetsu earthquakes in Japan

This paper provides a framework for evaluating the effects of population ageing on disaster resilience. In so doing, it focuses on the 1995 Kobe and 2004 Chuetsu earthquakes, two major disasters that affected Japan before the 2011 Great East Japan earthquake. It analyses regional population recovery on the basis of pre-disaster and post-recovery demographic characteristics using defined transition patterns of population ageing. The evaluation framework demonstrates that various recovery measures make different contributions to disaster resilience for each transition pattern of population ageing. With reference to regional population ageing, the framework allows for a prediction of disaster resilience, facilitating place vulnerability assessments and potentially informing policy-making strategies for Japan and other countries with ageing populations.

Expansion of the Nishinomiya Built Environment Database

The Nishinomiya Built Environment Database, which can be used to analyze the disaster process of the 1995 Hanshin-Awaji Earthquake Disaster in Nishinomiya City, has been expanded with new data entries. The database contains the following very detailed datasets: (1) the urbanization area base map, (2) casualty data, (3) three sets of building damage data surveyed by the Nishinomiya City, the Architectural Institute of Japan and the City Planning Institute of Japan, and the Kobe University, (4) building property data based on the real estate tax roll, (5) photographs of the damaged buildings with the information on the place and orientation of the picture, and (6) the estimated distribution of the seismic ground motion. The seismic ground motion was simulated for the southern part of Nishinomiya City and two verification sites in Kobe City and Amagasaki City. In the simulation, the borehole data of public facilities were used to model the surface soils as one-dimensional layers, taking into consideration the fact that the spatial distribution of the sediment/basement interface forms a slope. The model of the fault rupture process simulated the characteristics of the seismic motion at basement level, and amplification effects of the surface layers were evaluated based on multiple reflection theory. The distribution of peak ground acceleration and peak ground velocity was estimated from acceleration response spectra at each borehole point. In addition, the relationship between simulated seismic ground motion and building damage was studied based on newly proposed band-passed spectrum intensity using the expanded database. This confirmed that detailed categorization is necessary in order to evaluate the fragility functions, especially for reinforced concrete structures. The database should provide fundamental information for identifying the relationship between the ground motions and the extent and pattern of building damage, or the pattern of the occurrence of casualties.

HOW MANY REPAIRABLE HOUSES WERE DEMOLISHED?: Debris management of the 1995 Kobe Earthquake@@@－どのような物理的被害の建物が解体されたのか－

The 1995 Kobe earthquake damage results in 20 million tons of debris and 125,000 units of new housing needs. But many repairable houses were demolished by using subsidy for housing demolition. New findings about the debris amounts and housing needs were clarified by comparing physical housing damage and building demolition. 1. 81% of severe damage buildings, 51 % of major damage buildings and 21.5% of minor damaged buildings were demolished in the process of recovery. 2. When the minor damaged buildings were repaired, 5.5 million ton of debris, and all the reparable buildings were repaired 7.75 million tons of debris were reduced. 3. Subsidy for building demolition could increase the amount of debris and housing needs.

Environmental Transition and Natural Disaster

Recently, Japan has had three serious natural disasters: the eruption of Mt. Unzen-Fugendake, starting in 1990, the tsunami caused by Hokkaido Southwest, Earthquake in 1993; and the Great Hanshin-Awaji Earthquake in 1995. Natural disasters such as earthquakes and volcanic eruptions sometimes cause a large number of people, many of whom have lived all their lives in one place, to be uprooted from homes and familiar surroundings (e. g., Miura, 1995).