مطالعۀ نقش عوامل محیطی در توزیع استقرارهای ایلام قدیم و میانۀ شهرستان اردل، با تأکید بر چشم انداز کارست

Environmental factors have always played a significant role in the formation of human settlements. One of these environmental factors is karst. Karst regions have very specific geographical conditions. In this article, the impact of karst on the formation and continuation of Elamite settlements in Ardal County has been studied. Landscape features of karst, such as poor soil for agriculture and difficult access to surface water, are not suitable for sedentary life. Distribution of population and human settlements in a geographical area has a great influence on the structure and function of human activities. Not only will these distribution patterns be affected by social and cultural factors, they were highly dependent on natural phenomena; because nature is a context of human geographical activities. In this paper, we have studied and analyzed the role of environmental factors in spatial distribution and configuration of human settlements during the Elamite period in Ardal Count. Karst landscape is useful for nomadic people and we can understand such a life in Elamite era among the archaeological evidence and Mesopotamian inscriptions. Therefore, this study attempted to explore these regions from the Elamite era through an interdisciplinary approach involving archaeology, Archaeometry and history of northern Susa and Anshan.
Keywords: Karst, Ardal, Elamite Era, Lu. Su, Nomadism.
 
Introduction
The geographical determinism has sometimes definitely restricted social development and opens up at times an opportunity to development social factors. Social conditions is always under the influence of environmental indicators and one of which is karst; indeed, one of the geographical determinants can be found in the so-called karst landscape. Karst structures are a part of those environments that due to their inherent sensitivity, specific hydrological and geomorphic complexities, it has not been possible to interfere with and therefore human beings have long tried to adapt themselves to this environment. However, about 25 per cent of the world’s population lives in karst areas (Veni et al. 2001: 69). Due to inadequate agricultural soil, demanding access to surface water, and complex geographic conditions (Telbisz et al. 2013: 140), karst areas have generally not been appropriate places for permanent settlement in the ancient times. However, the Zagros Mountains have been regarded as one of the most important dwelling regions of Iran from the distant past and all karst forms and features, including karst springs, forests, karen, cave and rocky shelters can be observed (Ghorbani 2015: 519). Chaharmahal and Bakhtiari Province, located in central Zagros, has a capacity of over 60% from the perspective of karst conditions (Raeisi 2014: 1-5). There are many karst springs in the province, among which the most famous ones are Pir Cave, Shalamzar, Farrokhshahr, Brom Lordegan, Dimeh, Sadan and Sarab Babahidar (Riahiipour & Khalili 2012). Of the karst formations located in this province, it can be refered to Asmari, Sarvak and Ilam ones (Chitsazan et al. 2016: 97).
Aims and research necessity: Regarding the issue of mobilization in the Iranian plateau, many archaeologists have addressed role of this lifestyle in the social structure of prehistoric societies (Alden 2015; Abdi 2003; Alizadeh et al. 2010); however, this lifestyle as an entity as a whole, and its formation under the influence of the karst landscape in the historical era (Ilam) have received little attention. Therefore, the present study seeks to address one of the most important prospects in central Zagros, namely karst, and also devote itself to study concerning mobilization using remote sensing, and historical sources including Elamite place names.
Research questions and assumptions: Considering the considered topic, in order to come to the favorable aims, the present article intend to addressed this question that has the geological situation of the region, especially the karst landscape structure, had any effect on the type of settlements of the old and middle Elam periods and how these impacts is visible in their nomadic subsistence?
Research method: In order to achieve the desired results, the role of environmental and geographical factors on how Elam’s period settlements using archaeological surveys of the region and their location in GIS maps are studied; also, the role of karst formations as one of the most important features of the earth in Chaharmahal and Bakhtiari province will be evaluated.
 
Karst landscape in Chaharmahal and Bakhtiari province and Ardal County
Karst landscape is one of the most important geological formations of Chaharmahal and Bakhtiari province. Despite the importance of this formation in the forming of ancient settlements, little attention has so far been paid in archaeology of Iran. The most important karst landscapes in Chaharmahal and Bakhtiari province are the Asmari-Ilam and Sarvak formations. This landscape is crucial in determining how ancient settlements has been located. Among sites under study in Ardal County and based on Esmaeili Jelodar’s and Khosrowzadeh archaeological surveys in two central and midland sections (Esmaeili Jelodar 2007; Khosrowzadeh 2008; 2009; 2010) and their location in GIS environmental maps, 56.25 per cent of identified settlements in the central part of Ardal (18 settlements) have been formed on the karst formation (figure 1 & 2). This figure is higher for the midland area and is equal to 74.6 per cent (56 settlements), which would be an interesting figure for the Elamite settlements in the region. Therefore, it can be said that throughout Ardal County, 65.4 per cent of the Elamites settlements have been formed on karst settlements (Figures 1 and 2). It is interesting to note that despite the importance of this landscape in Chaharmahal and Bakhtiari province, few archaeological sites of the province have been studied with such a view. It should be noted that karst not only played an environmental role in human settlements (in here Elam period) but also influenced the behavior, beliefs and social conditions of the inhabitants themselves (Stevanovic, 2015: 22). Therefore, locating the high percentage of Elamite sites on karst areas will be quite noticeable.
 
Conclusion
As identified, environmental factors have had a considerable role in the Elamite settlements of the Ardal County. In Ardal, karst and factors related to it can be known as the most significant reason behind dwelling in the Elam period; considering importance of this topic and lack of conducted studies so far concerning karst in ancient settlements of Charmahal Bakhtiari province, the article intends to examine this topic.
Karst is one of the important landscapes of the Zagros region; given the abundance of this landscape, the karst in archaeology has not been adequately studied in the way it deserved to. Caves, rock shelters, and abundant springs besides Cherts caused karst areas to be suitable for humans in the Paleolithic era. However, by reason of inappropriate soil for agriculture and demanding access to surface water, Karst areas has not been suitable for rural life and urbanization in historical epochs. Nevertheless, the existence of abundant pastures and springs in karst areas of Zagros are the appeals that has attracted human beings to this areas. In Ardal County, 65 per cent of the Elamite settlements has been located in the karst landscape; hence, it does not should appear very simplistic, but it should be studied correctly and with scientific approaches.