アジアメガシティ•ジャカルタの将来人口分布と高齢化の特徴に関する考察: 東京を比較対象として

摘要

The growing Asian megacities require strategic management that accommodates the rapid aging of their future populations. Such cities are currently confronted with urban issues such as social divide, economic inequality, and environmental problems. Therefore, it is useful to predict the adverse outcomes expected from these issues combined with an aging population. This study estimates the distribution and aging of long-term future (2050) populations in Indonesia's capital city, Jakarta. To this end, raw data collected during the population census of 2000 and 2010 were organized, and a GIS polygon data for small administrative units, which is suitable for spatial analysis of time series data, was developed. The Japan International Cooperation Agency has assisted Indonesia's Central Agency of Statistics in improving the accuracy of counting the 2000 Census data and developing small-unit statistics. However the data of population in the small unit, which is organized by age groups and sex, are not provided, neither GIS polygon data for the time series analysis is. To examine the validity of the estimation method and enable comparison, the population distribution and aging of Tokyo's population was projected from existing data to the year 2050. Based on cohort change ratios, the Jakarta and Tokyo populations were estimated by the same method. The National Institute of Population and Social Security Research has developed a method for estimating the long term future of Tokyo's residents. The results of the National Institute were compared with those of the present study. The results were consistent, verifying that the proposed method is suitable for projecting the 2000-2010 Census data into future population estimates. The results reveal that ⅰ) the aging of Jakarta's population will accelerate, particularly in areas of high population density. The elderly population will be 4 times higher in 2050 than in 2010, The distribution of aging rate in Tokyo in the year 2010 and 2050 correlates to the distance to the center, while the distribution of increasing rate of elderly population in Jakarta correlates to the distance to the center, ⅱ) Considering Jakarta's history and recent suburbanization, it is useful to estimate the city's long-term population distribution and aging dynamics from the 2000-2010 Census data, ⅲ) High density areas in central Jakarta will become less populated, while the populations of low to medium-density suburban areas will dramatically increase. In Jakarta, high-density areas include informal settlements and suburban areas are affected by urban sprawl. In central areas with high density, mostly informal settlements, the overcrowded problem might decrease but aging problem will increase. In some growing suburban areas, both the densification and the rise of elder population will be problematic, which would require adequate policy. The characteristics of population distributions in other Asian cities are now very different from those in Tokyo. Many of these cities are affected by serious urban problems including social and economic divide and environmental problems. Under these conditions, the future problems caused by population aging are likely to differ between Tokyo and Asian megacities in developing countries. This paper aims to project the population distribution and aging from limited demographic data available in Jakarta. As the significance of the projection becomes recognized, and data analysis promoted in developing countries, more accurate projection using well-maintained data is expected to be realized in future. Such projections will contribute to long-term strategies.%人口1千万人以上を抱えるメガシティの数は增加傾向にあり、特に途上国のメガシティは今後も人口増加が予想される。メガシティが最も多く存在しているのがアジア諸国である。各都市は目先の都市課題への対応を迫られ、交通などインフラや住宅地整備に追われている。他方、長期的に見ると、アジア諸国では、日本並みかそれ以上のスピードで高齢化が進行するといわれている。巨大な人口規模を有するアジア諸国のメガシティでは、膨大な人口が一気に高齢者となることが容易に想像できる。現在急速に進むインフラ整備や都市開発は、やがて訪れる高齢化社会を考慮しなければならない。例えば、医療•福祉など高齢化にともないニーズの高まる公共サービスを見越して、現在進行中の開発が行なわれるとしたら、将来予見される都市問題の低減につながり、その意義は大きい。都市の空間的な人口分布やその将来予測は、長期的に都市を見通すにあたり、重要な基盤情報のひとつである。しかしながら、広大なメガシティの都市圏を網羅する比較的ミクロな空間単位注の人口統計データの整備•分析は、途上国のメガシティにおいて挑戦的な課題となっている。