This study focused on the fact that the patterns of spatial distribution of the Neolithic and the Three Kingdoms period in Amsa-dong site is different. Although the time difference between the two periods is about 3,000 years, there are no archaeologi...
This study focused on the fact that the patterns of spatial distribution of the Neolithic and the Three Kingdoms period in Amsa-dong site is different. Although the time difference between the two periods is about 3,000 years, there are no archaeological materials between them, so it was also analyzed with regard to the context of changing patterns of spatial distribution of the site. The two aspects can be presumed that the influence of the natural environment prevailed rather than anthropogenic intervention due to the characteristics of the times.
In order to proceed with the study, the characteristics of the site were first examined. The site is highly influenced by river overflows, but the site is suitable for the formation of villages because of their location. Next, as a result of analyzing the function and occupation of the site through the features and artifacts, both periods sites were a residential base with high sedentism, and the occupation was considered to be long for both the total occupation length and the annual occupation length. As a result, it was judged that the occurrence of unoccupied period and change of patterns of spatial distribution in Amsa-dong site is difficult to find the reason without considering natural disaster.
Therefore, the Holocene palaeoenvironments analysis was conducted to understand how and how much the natural environment affected the Amsa-dong site in the past. First, a study on climate change and sea level fluctuations that affect human life in general was examined. In early Holocene, the climate was warmer and more humid than in previous period, creating a backdrop for the arrival of the Neolithic era on the Korean Peninsula and rising sea levels. In middle Holocene, Neolithic period of Amsa-dong and the climate optimum period involved, was generally warmer and more humid than in the early stages, but about 6,000 BP, cold-drying trend appeared. Sea level was estimated to have been about 1 to 2 meters higher than it is today. In late Holocene, the climate gradually became cold and dry, and the sea level gradually dropped to the present level.
And then, sea level rise simulations were used to understand the effect of sea level fluctuations caused by climate change on Amsa-dong site. As a result, past sea level fluctuations had no visible effect on there. Judging from this, the cause of unoccupied period and change of patterns of spatial distribution in Amsa-dong site may be a massive flood, such as the Great Flood in 1925, which swept across the area. Therefore, it was identified that flooding and topographic changes by floods could be the main causes of them by analyzing the cycle and impact of great flood.
In order to examine this, palaeogeomorphic analysis was conducted. First, it was confirmed that the site can actually change through the data that can examine the terrain of Amsa-dong site in the past. Next, GIS was used to grasp the past and its changes of Amsa-dong site. As a result, it was found that the topography of Amsa-dong site has been changed continuously, and it was determined that the topographical changes that occurred in the Neolithic and the Three Kingdoms periods were caused by flooding considering the characteristics of the times.
Finally, the changes in the patterns of spatial distribution in Amsa-dong site were interpreted based on the previous analysis. The great flooding could not only destroy the site, but again confirm that it was a decisive factor in the topographic changes. After that, the appearance of topographical changes were assumed using palaeogeomorphic indication data. As a result, it was interpreted that the natural embankment moved toward inland more in the Three Kingdoms period than in the Neolithic era, resulting in changes of spatial distribution patterns.
In addition, an archeological approach was used to reinforce the interpretation of topographic changes. First of all, causes of migration of Neolithic group related to the destruction of the site includes declining food supply stability due to climate degradation, population growth, early farming, and flood damage. This paper judged that all causes were compounded, assuming that the human group would follow the criteria of economic rationality. In other words, the flooding, which could be handled in earlier days, couldn’t be overcome when climate worsened, population control weakened, and if early agriculture was carried out, the marginal profit declined. That is, if the economy weakened, it lead to failure to overcome it.
Meanwhile, it was considered that it was difficult to form a settlement in Amsa-dong site in unoccupied period due to the change of terrain by flooding. The nearby sites show that stable terrain or suitable for agriculture was preferred. Later, in the Three Kingdoms era, terrain of Amsa-dong was stabilized, resulting in forming a settlement. By the way, features of the Three Kingdoms are now more concentrated in eastward. The reason for this is judged as the location change due to the topographical change. This point is also the location where the wetland should be located. In other site examples, the wetland is believed to have naturally or artificially extinguished, and then it was interpreted that a settlement was formed over it.
Interpretations through topographic changes and archaeological aspects can help to understand the past as well as Amsa-dong site. For example, the study of the Neolithic Period on the Korean Peninsula tends to examine several sites together. This is important in the context of the times, but more intimate understanding of individual site is needed for a more detailed discussion. It may also serve as a reference for future site investigations. Estimates of topographic change patterns suggest that after the Neolithic period, archaeological sites could be located further inland. In addition, it may be possible to explore additional sites through the palaeogeomorphic analysis data. Conclusionally, the significance of this study is to clarify concretely through the quantitative and empirical review that goes beyond the threadbare and abstract common sense research that the Amsa-dong site was affected by the natural environment.