<論説>社会の流動性とレジリアンス : 中央ユーラシアの人間と自然の相互作用の総合的研究の成果から (特集 : 災害)

• Main Author: 窪田, 順平
• Other Authors: KUBOTA, Jumpei, クボタ, ジュンペイ
• Format: Article in Journal/Newspaper
• Language: Japanese
• Published: 史学研究会 (京都大学大学院文学研究科内) 2013
• Subjects: 200; glacier
• Online Access: http://hdl.handle.net/2433/240287; https://doi.org/10.14989/shirin_96_100

地球研・イリプロジェクトでは、中央ユーラシア乾燥・半乾燥地域を対象として取り上げ、過去一○○○年間の気候・環境変動を多様な手法で明らかにするとともに、それに対する人間の応答を明らかにすることを試みた。中央ユーラシアの生態環境は、大陸スケールの東西の降水量分布と季節性の違い、南北の気温差に起因する多様性と、わずかな気候のゆらぎで乾燥・半乾燥が入れ替わる変動性とを有する。開放的な地形もあって、遊牧という移動性の高い生業は、多様で変動の大きい環境と調和的であった。一方で水資源の稀少性は、農業集団にも時として移動や生業の転換を強いた。こうした移動性の高さ、社会の流動性が、中央ユーラシアの根底にある。乾燥・半乾燥地域社会の移動性の高さは、東南アジアなどの海域社会と同形性を有する。東南アジアの海域社会は、その流動性の高さが災害に対する社会のレジリアンスを発揮するとされるが、乾燥・半乾燥地域にも、同様な傾向を見出すことができる。 Human beings have continually strived to adapt to changes in the environment. Central Eurasia, which is climatically sensitive and alternates between semi-arid and arid conditions, is an excellent location for historically tracing human reactions both to past climate changes and anthropogenic activities. At the same time, people in Central Eurasia are facing contemporary environmental problems, such as the tragedy of the vanishing Aral Sea caused by the overuse of natural resources in modern agriculture. The research project "Historical Interactions between Multi-cultural Societies and the Natural Environment in a Semi-arid Region in Central Eurasia, " conducted by the Research Institute for Humanity and Nature, combines analysis of historical documents, archaeological remains and natural proxies such as ice cores, lake sediment samples, and tree rings in order to describe the historical interaction between human activities and natural systems in the semi-arid region of Central Eurasia. The aim of the project was not to reach a so-called historical understanding of the rise and fall of ethnic groups, but to discover the history of adaptations by human beings to both environmental and societal changes in semi-arid regions of Central Eurasia through a focus on natural resources use as a contribution for tackling present global environmental issues. The project reconstructed the change of the climate in the area during the past 1, 000 years by using various proxies. Reconstructed temperatures and precipitations indicated that the period from AD1000 to AD1500 was warm and dry, while the Little Ice Age (LIA), from 1500 to 1850 was cold and wet. Using the reconstructed temperatures and precipitations, we estimated two important factors relating agriculture to nomadic activities, namely, river flow, including glacier fluctuation, and grassland distributions. The long-term trend of river flow corresponds well with the reconstructed lake level of Lake Balkhash, indicating that there was a trend of decreasing lake level from the 10th to 13th century. A chronological database describing the rise and falls of settlements indicates a clear change in the distribution pattern of agricultural settlements in the Syr Darya Delta from the 13th to 15th centuries associated with river course change, which resulted in severe declines of the Aral Sea lake level in the 13th to 15th centuries. The warm and dry climate in early medieval times might have accelerated the development of agricultural and trading activities, and consequently contributed to the flourishing of the area, especially oasis cities in the Syr Darya basin of western Turkestan from the 7th to 13th centuries. Also, the cold and wet climate in the LIA, might have affected the declines of oasis cities and the increase of nomadic activities. Places and populations of nomadic groups identified by historical documents shows that nomadic groups expanded their activities in the area newly covered by grass. These outcomes demonstrate that ecosystems in Central Eurasia have a wide variation, but have fluctuated due to climate change. Social flexibility, such as high mobility and subsistence complex patterns were major ways of adaptation to this environment. Also, societal mobility sometimes reduced societal conflicts. After a long transition marked by the rise and fall of various ethnic groups and countries, a secure and definite border divided the region between Russia and Qing in the 18th century. At the same time, the people of the area experienced a great change in their lifestyle, caused by the introduction of modern agriculture. The settlement policy and collectivization of the agricultural sector from 1929 triggered serious social confusion in Kazakhstan, resulting in the loss of a large number of nomadic populations. Under the "transformation of nature" ideology of the Soviet Union, Kazakhstan was forced to become one of the major crop production areas in the Soviet Union, causing excessive development, which ignored environmental capacity and exerted significant impact on the area. In addition, these development policies were applied in a fashion that ignored and destroyed traditional social systems. Especially, the newly applied production system including the division of labor, together with the migration of skilled peoples from other countries as leaders for collective farms, prevented the accumulation of agricultural knowledge, and also caused the loss of traditional knowledge on nomadic pastoralism and the subsistence complex. Moreover, societal confusion caused by the collapse of the Soviet Union implies that societal flexibility in the area could be a very important factor in the resilience of society to both natural and societal impacts. This is one of the keys to understanding contemporary environmental issues in Central Eurasia. We can also see a similar societal flexibility or high mobility in "sea nomads" in South East Asian islands. Societal flexibility is thus one of the key concepts for understanding the resilience of a society.