Impacto social thailandia

WHO Conference on Health Aspects of Tsunami Disaster in Asia
Phuket, Thailand 4–6 May 2005

Who Was Affected? The Demography of Tsunami-Affected Population
Deborah Balk and Yuri Gorokhovich Center for International Earth Science Information Network Columbia University

Assessing Needs and Measuring Impacts

Overview
• Population – exposure – composition – measurement • Crude deathrates • Socioeconomic profiles of the exposed areas • Where are people now? • A hazardous world: a multi-hazard approach

Population exposure
• What do we know about the spatial distribution of human population? – People do not live uniformly with respect to: • National borders • Coastlines • Other geographic features, including hazard-prone regions – Some hazard prone regions may “attract”population, e.g., volcanic soils – Coastal zones support fishing, and access to markets (historically) – People move • Daily movement—commuting to work, markets, schools • Seasonal movements—tourist, labor-migration • Longer term movements—life-cycle (childbearing, retirement), permanent migration, forced migration

Population density
• Asia—particularly south and southeast Asia—are the most denselypopulated place on earth Coastal zones have disproportionately high population densities – 450 persons/km2, Asia – vs. 175, globally Coastal areas are more urban

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Source: CIESIN, GRUMP v1 (alpha) http://beta.sedac.ciesin.columbia.edu/gpw

Demographic Composition
• Age distribution: Asia is young. – Proportion of population < 15 yrs ranges between 25-35% as compared with 20% or lowerin North America and Europe • Household size and composition. – Larger, extended, with traditions of fosterage • Gender – Displacement affects women and men differently

Population estimation
• Who was exposed? • Who was at risk? • Who was affected?
– Lost lives – Lost livelihoods – Displacement

Who was exposed to the tsunami?
• Wave heights were reported to be between 30-40 feet attheir maximum – Persons below roughly 40 feet, or 10 meters, in elevation At close distance to the coastline – In most places, the waves were reported to go no more than 1-2 km inland from the coast • Except in parts of Sumatra were there were reported as far inland as 4-5 kilometers Additional damage from the earthquake – And perhaps interactions with flooding How to quantify the number of personsexposed?

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Calculation
• Estimate the population residing
– Within 1 and 2 km buffers of the coastline – And, at an elevation of 10 meters or less

Why is population estimation tricky?
• Data formats are not easily comparable – Population data come from censuses: • Irregular-shaped units • “Who slept here” or usual residence;

Elevation data come from earth observingsatellites (SRTM):
Uniform gridded dataset

Coastlines must match, but often don’t

Shorelines of data sources do not match: Black shoreline: ESRI Red shoreline: Administrative Units, BPS The finer the scale the more the differences matter

Data transformation: administrative units to grids

Vector and raster data combination
population data 2 km buffer shoreline Population data are nowGridded (i.e., rasterized) Shoreline is vector (convert to raster)

Results
County India India India India India Indonesia Indonesia Indonesia Indonesia Indonesia Aceh* Bengkulu Sumatera Barat Sumatera Utara 57,301 20,720 43,026 71,276 69,427 41,391 8,077 5,662 8,024 4,326 558 Andaman and Nicobar Islands Andhra Pradesh Pondicherry Tamil Nadu 7,248 276,086 560 130,644 Region Area of Region (km2)Population exposed, 2005 Within 1 km of coast % of regional population 6.8 0.3 9.2 1.1 4.8 1.3 2.2 1.1 7.6 2.5 21.6 2.4 2.3 3.6 13.7 Within 2 km of coast % of regional population 8.8 0.7 12.6 2.2 10.0 2.6 4.5 2.2 11.9 4.7 34.1 3.8 3.7 5.5 16.8

Count 1,642,855 10,496 295,676 84,923 565,132 571,169 120,453 21,271 108,666 136,490 550,208 109,366 56,340 209,762 57,789 116,951 89,888 11,401...