Abstract
Aleshtar plain is central part of Selseleh county and located in North Loristan province. This plain is region lush and with pleasant weather and rich soil. This area has been from prehistoric period so far always settlements folks and different groups human. Location of Aleshtar plain and proximity with Northern areas Zagros, Central Plateau, Southwest Iran, and Mesopotamia, for a long time to this area has particular importance of communication. Authors, after explaining the climate and ancient roads Aleshtar, have analyzed dispersion form of ancient and historical settlements this area. In this regard, using with ArcGIS software (version 10.3) location of each site is specified in Aleshtar. Output of ArcGIS software, is four maps in Chalcolithic, Bronze and Iron, Historic, and Islamic periods. After studies is specified approximate route of ancient road in Aleshtar plain (north-south road in central Zagros). Therefore, combining the two points, included, ancient road north-south and also distribution of ancient and historic sites in Aleshtar plain, in before and after Islamic periods, this question was raised: what role has this ancient road in Aleshtar plain in the formation ancient settlements? For this question, authors with preliminary survey in Aleshtar plain they had this hypothesis: basically, this ancient road from Islamic periods has played a pivotal role in the formation of sites. Analysis distance of each site from this ancient road has showed, most archaeological sites has been formation in Aleshtar plain from the Islamic period along this route; In the Pre-Islamic periods, hasn’t been focus center of settlements around this ancient road with distance of about two kilometers. Data of this study is based on archaeological research Ali Sajjadi in 1998 and Davood Davoodi in 2006 and 2007. Also, authors have done again surveyes in this area.
Keywords: Aleshtar plain, Settlement, Ancient roads, and GIS Analysis.

Introduction
Selseleh County is located in north of Lorestan and in South of Hamedan Province. From Aleshtar city is mentioned in various sources. This point has been indicative importance this region in Pre-Islamic and Islamic periods. Archaeological survey that so far has been done in Aleshtar plain, confirms importance of this area. In Aleshtar before all, by Oral Stin has been done archaeological survey (Stin, 1940). Colar Goff in during archaeological surveys in North Lorestan; She has also surveyed Aleshtar (Goff, 1968). In 1998, Ali Sajjadi was surveyed Aleshtar from administration of Cultural Heritage of Lorestan province. Now, report her work is in archives administration of Cultural Heritage of Lorestan province (Sajjadi, 1998). Furthermore, in 2006 and 2007, Davood Davoodi was surveyed historic and ancient monuments Aleshtar in during two seasons (Davoodi, 2006 and 2007). Authors, in order to explain process settlement in Aleshtar plain, and measurement influence of climatic conditions area, and importance of ancient and historical roads of this region, have done draw a map ancient settlements of Aleshtar plane in Chalcolithic, Bronze and Iron, Historic, and Islamic periods. For this purpose, has been used from report of survey Ali Sajjadi (Sajjadi, 1998), and reports of surveys Davood Davoodi (Davoodi, 2006 and 2007), and also, again surveyes authors in this area. In this research, has been used for register ancient sites on the map from ArcGIS software (version 10.3). So, authors in this research try to analyze the following issues:
What role has this ancient road in Aleshtar plain in the formation ancient settlements? And essentially, role of road north-south in Aleshtar plain at what period is seen? The main hypothesis of this research, it is: Around of ancient road in Aleshtar plain in Islamic period has been settlement. In the Pre-Islamic period, hasn’t been focus center of settlements around this ancient road with distance of about two kilometers.

Settlements of Aleshtar plain from prehistoric to Islamic periods
The Communication route that has been connected West to Southwest of Iran (Hamedan and Kermanshah to Khozestan plain), one of the most important route of communication in Pre-Islamic periods, and this road has been connected West and Northwest to regions of Southwest Iran. Continue this road has been crossed from Aleshtar plain. Study location of sites from prehistory to Islamic periods has points, has been effective in description of problem, settlement patterns and also role of ancient roads in this area in formation of settlement patterns. In study area, were identified in total 96 settlements sites. The sites were divided into four groups, that including Chalcolithic, Bronze and Iron, Historic, and Islamic periods. According to, in Aleshtar plain were identified 27 sites related to Chalcolithic period. It seems, in this period entire Aleshtar plain has been inhabited. Most of settlements are seen in around rivers of Kahman and Zaz. However, in the eastern part of Aleshtar, is seen number large sites settlements related whit this period. Also, in this area were identified 28 sites related to Bronze and Iron periods. Checking the distribution map of sites in these periods, interpretations related whit Chalcolithic period is show. In this period entire Aleshtar plain has been inhabited. In Historic periods (especially Parthian period), we see increasing number of sites in Aleshtar. In this area were identified 82 sites related to Historic periods. Furthermore, in Aleshtar were identified 52 sites related to Islamic period. In this period number of sites has dropped relative to previous period. In this period, aggregation of sites is in central area of Aleshtar.

Conclusion
Climatic and environmental conditions also ancient roads, is two major factors in relation to settlement patterns in Aleshtar plain from prehistoric to Islamic periods. In Chalcolithic, Bronze and Iron, and Historic periods is settlement of pattern absolutely scattered and dependent on water resources and land. In these periods aren’t interpretable of focus in sites Aleshtar. In Islamic period, aggregation of sites is in central area of Aleshtar. Two to three kilometers in North and West in Modern city of Aleshtar has largest number of sites from Islamic period. In Islamic period settlement of pattern is around ancient road (north-south) in Aleshtar plain.

Abstract
In 1931, The archaeological sites of Sulaiman Tapa, Tel-e Baksaye and Seba’āt-e Kahriz were registered in the National Iranian Registry of Sites, but since then, their exact location remained unknown. According to the Cultural Heritage monuments list, the Location of all three sites are in Iraq. In this article we have attempted to find clues about the location of these three sites, according to De Morgan’s reports, satellite photographs, Historical maps and documents related to the late Qajar and early Pahlavi periods of the Iran-Ottoman Border conflict. Our evaluations indicate that these three sites are located in three different locations inside modern Iraq- Iran’s political border somewhere around Ilam province. In this article, the authors try to answer these three questions: Have these sites been inside Iranian border in Qajar and Pahlavi periods? Are these three sites traceable? Could the mentioned sites be dated to the Elamite period?
Keywords: National Iranian Registry, Sulaiman Tapa, Tel-e Baksaye, Seba’āt-e Kahriz, Pusht-i Kuh Luristan, borderland.

Introduction
Jean-Jacques De Morgan was a French mining engineer, geologist, and archaeologist who had travelled to all across the Iranian plateau before starting excavations at Susa. During his visit to Pusht-i Kuh, De Morgan was hosted by Hussein-Gholi Khan, the governor of this region for more than a month. in Etudes geographques, he indicates to these ancient sites of Sulaiman Tapa, Tel-e Baksaye and Seba’āt-e Kheriz (Tchahar-riz) located west and south of Pusht-i Kuh beyond the Iranian current border. André Godard, another French archaeologist was assigned to serve the new-founded Iranian Archeological Service in 1922. He was responsible for registering and restoring the national heritage monuments. The first three monuments that were recorded in Godard’s list were Sulaiman Tapa, Tel-e Baksaye and Seba’āt-e Kheriz. It seems that Godard had used De Morgan’s book to present Pusht-i Kuh monuments.

Discussion
During the last centuries, the western border of Iran has always been the matter of dispute between Iran and its neighbors. The conflicts between the Iranian and Ottoman governments began in the Safavid era. In 1850 some joint commissions were appointed to settle the border disputes and their work were underway for about 70 years. These commissions were mediated by Russian and British representatives in the region. The present borders of Iran and Iraq are the result of these commissions. During and before these commissions the nomads of the region were easily crossing the border. The Baksaye or Bagh-e Shahi area nowadays on Iraqi soil was part of the Pusht-i kuh governor’s estate. But as the Pahlavi era began, the last governor fled to Iraq and the region was permanently separated from Iran.
De Morgan only gave an explanation of his visit to the Tursaq area. He has been silent about the two districts of the Baksaye and the Tib River Basin. It seems that he has never been to these two areas. It sounds that local people or the governor himself have informed de Morgan about Tel-e Baksaye and Seba’āt-e Kahriz. he may also have access to the map of the Border Commission in which these two sites have been mentioned. In the map of boundary delimitation committee all three areas of Tursaq, Baksaye and Seba’āt-e Kahriz Sabah are attested and their location are shown.

Conclusion
Some 90 years after registering of Tursaq sites (Sulaiman and Zirzir Tapa), as well as Tel-e Baksaye and Seba’āt-e Kahriz sites in the of Iranian National list of Registered Sites, an opportunity presented itself to gather information on the latter using written documents, historical maps and remote sensing techniques. The Tursaq complex, which has been registered under the name of Sulaiman Tapa, is essentially two separated, yet nearby settlements. According to the illustrated report by the Iraqi Antiquities Department published in 1967, Tursaq has deposits dating to the Achaemenid and Seleucid periods, whereas according to Jacques de Morgan the sites date to the Kassite period, while the National Iranian Registry of Sites refer to the site as Elamite. As for Baksaye, de Morgan only refers to the site’s name and it is registered on the Iranian list. Based on the Iraqi Atlas of Archaeological Sites, the latter site, a cluster of several small sites in the Baksaye area next to the Iran-Iraq border in Mehran region, dates back to Old Assyrian, Kassite and Islamic times. The third site, erroneously registered on the list as Seba’āt-e Khariz is in fact Seba’āt-e Kahriz (Seven Kariz) in the north of the Maysan Province of Iraq. According to De Morgan and the Iranian list this site is Elamite, but our analyses of satellite and aerial images suggest that the site might in fact belong to Seleucid-Parthian, and perhaps Sasanian periods. 

Abstract
The city of Ghorveh is located in the south east of Kurdistan province and in the east of central Zagros. This city is a part of the Qezal Owzan River Basin. This region has an archaic history from prehistoric periods to the Islamic ones due to favorable geographical conditions. According to the surveys, in the Ghorveh City, 35 sites dating to the Parthian period have been identified. This paper studies the Settlement Pattern of Parthian sites and their relationship to the geographical environment. The settlement pattern initially divided into four clusters based on the area of the premises and then five factors were considered based on the maps drawn from the GIS. These factors include: Altitude from sea level, The distance from the river, The slope, steep direction and Land use. In addition, taking advantage of Spss software, the settlement clusters have been statistically studied and their correlation and relevance using factors were discussed. Based on the results, there is a significant relationship between clusters and some factors. In general, most of the sites are located in clusters one and two that are less than two hectares. In terms of settlement pattern, some of these sites were temporary settlements that were grazing and a number of others are not known exactly, but probably there were fixed settlements that were small villages of agriculture and livestock. But clusters three and four were all permanent settlements that were engaged in agriculture, horticulture, and animal husbandry. In general, two types of temporary and permanent settlement patterns observed in the Parthian period in the city Qorveh.     
Keywords: Ghorveh, Parthian, Settlement Patterns, GIS Software, SPSS.

Introduction
The Parthian dynasty is one of the most important Iranian historical kingdom who entered the arena in extremely difficult political and social conditions and revived some of the ancient Iranian features (Mohammadi, 2010: 4). This dynasty ruled Iran for nearly five centuries from 248 BC to 224 AD (Mohammadi, 1391: 13) they were able to establish cities and government centers (Kiani, 1374: 240). And their territory expands from the eastern parts of Iran to the Tigris and Euphrates. During this period, in addition to Sedentary and urban settlements, there are nomadic settlements. Examples of this type of nomadic settlement during this period can be found in the Central Zagros (Niknami & Mohammadi, 1394; Mohamadifar & Niknami, 2013; Niknami et al., 2013).
In Qorveh city 35 sites have been identified related to Parthian period (Behnia, 2008). Most sites of this city are small settlements (Mafi et al., 2009. 85). Parthian pottery is simple, glazed, imprinted, and clinched in Qorveh. But the most prominent Parthian pottery is in western Iran as well as in the Qorveh city of Klineik pottery. The pottery has been scattered from Kermanshah to the northern parts of Zanjan in terms of its geographical extension. Also from Chamchamal plain (Mohammadifar, 2007). Kangavar Plain (Young, 1975) and in historic sites of Bistoon, Jogar Malayer Tape, Noshijan, Ray, Shush, West Islamabad and Boroujerd have also been reported (Hernik, 1997: 117). 
In this area, there have been Sedentary and nomadic settlements since the pre-historic time. It is necessary to study the continuity of these settlements in historical periods. It is necessary to study the continuity of these settlements and types of Sedentary and nomadic settlements in historical periods. This research is based on data obtained from the field survey. In this research is used a descriptive-analytical method, and for accurate analysis of Parthian period settlement pattern in Qorveh city has been used the Gis software and Spss statistical software. Based on the available data, 6 factors are considered. Including: 1. Altitude above sea level 2. Distance from river 3. Distance from road 4. Slope 5. Slope direction 6. Land use. To analyze the settlement patterns, it is divided into four clusters based on size of the sites. Then, to analyze these clusters using factors and according to data type and purpose of research were used one-dimensional, regression and R-pearson tests of Spss software.

Identified Traces
In order to analyze the settlement patterns, the sites are divided into four clusters based on by size. According to the type of data which are nominal and scaled and the purpose of the research were used One-Dimensional, Regression and Rpirson tests of the Spss software. This analysis consists of two descriptive and inferential stages.  
The cluster one is the largest in the series. sites of this cluster are less than 1 hectare. According to the data, %57/1 of the sites belongs into this cluster. Cluster two consists of sites between 1 and 2 hectares. The third cluster is sites ranging from 2 to 3 hectares and the fourth cluster consist of sites of more than 5 hectares.
The size of the sites was considered as an independent variable and the six factors mentioned as dependent variable. According to the results of multivariate regression test, there is a significant relationship between the size of the sites factor with other factors. This relationship was strongly inverse between The size of the sites and the distance from the river was Relatively Severe Reverse.  Briefly, Larger sites are closer to the river and as the sites are smaller, they appear farther from the river. But there is no relationship between the size of the sites with the factors of altitude and slope. In addition, to understand the test results, the Cluster diagrams need to be studied. By studying the cluster diagram it can be seen that clusters one and two are in all factor categories. For this reason, there is no correlation between all factors. 

Conclusion
Based on the results of the analysis on four clusters. Cluster One is the largest cluster, There are two types of settlements. The first type of settlements is far from the river so they are located at higher altitudes. The second type located on the lower elevations and slopes near to the river. In the second cluster, the settlements are closer to the river. these sites are located at higher altitudes and different slopes. In the third cluster, the sites are closer to the river. These sites are located at low slope and low altitude. The fourth cluster settlements approach the water source. But in terms of slope and altitude are at different altitudes. In clusters one and two, there is Sedentary and nomadic settlement, But clusters three and four are Sedentary settlement that constituted a small percentage.
In general, the settlements of Qorveh city in Parthian period are in two forms: Sedentary and nomadic. Sedentary settlements have agricultural and Husbandry economies due to their geographical Charactristics, But seasonal settlements used to grazing. In fact, most of the sites include seasonal settlements. This type of settlement in this region have been prehistoric times of chalcolithic and Bronze Ages (Kura-Araxes) and in this period we also see the continuation of this type of settlements.

Abstract
The Chalcolithic Age is one of the most important prehistoric periods in Iran. The transformations of this period in the Central Zagros have emerged in continuation of the Neolithic period.  One of the important areas of Central Zagros, which had many settlements related to the Chalcolithic era, is Silakhor plain in the north of Lorestan. Despite the cultural richness of the Silakhor plain during the Chalcolithic Age, no purposeful study has been conducted to clarify the Chalcolithic status of this area. In this regard, in order to clarify the settlement models of the Chalcolithic era of Silakhor plain, this study is presented, which is a summary of Ahmad Parviz’s archaeological studies and purposeful studies by the researchers, In the present study, the authors have tried to find the answer to the following questions: What were the settlement models of Silakhor plain in the Chalcolithic era? How can the changes of settlement models in the old, middle and new periods of the Chalcolithic era of Silakhor plain be analyzed? It seems that several factors including water resources, altitude of Silakhor plain and state’s roads have been effective in the formation of settlements in this area during the Chalcolithic age. Studies conducted in this plain so far have shown 80 ancient sites related to the Copper Stone Age. Some of these sites involve all three periods of old, middle and new Chalcolithic era. The spatial data collected in this research have been studied by GIS science studies method and implemented in ArcGIS 10.3 software. The basis of these studies is the distance of each settlement area from the nearest river and its altitude level from Silakhor plain. These maps have been implemented in all three periods of old, middle and new Chalcolithic Age of Silakhor plain. 
Keywords: Central Zagros, Silakhor Plain, Chalcolithic Age, Settlement Models, GIS.

Introduction
The Chalcolithic Age (mid-fifth millennium to late fourth millennium BC) is one of the prehistoric periods which has witnessed important transformations such as population growth, enhancement of the quality of pottery, the use of copper metal, improvements in the quality of settlement construction and so on.  Some scholars consider this period to be a continuation of Neolithic transformations and some consider it as being independent of other periods. Archaeological studies conducted over the past few decades in the Central Zagros region have shown that this area has seen an increase in population during the Chalcolithic period. This increase in population is inferred from the number of archaeological sites recorded in this period compared to the previous period (Neolithic). Of course, the studies indicate that archaeological studies conducted in connection with the Chalcolithic Age of the Central Zagros, have focused mainly on the Gamasiab River Basin.
Silakhor plain has a suitable situation geographically and climatically.  The flat plain and fertile soil along with sufficient water resources have caused us to see a large number of ancient sites from the Neolithic period to recent centuries. Despite the conducted studies, so far no purposeful studies have been conducted to analyze the residential and settlement situation of the Chalcolitic era of Silakhor plain. In this regard, the researchers, while exploring the studies conducted in this plain, have re-examined the ancient sites of the Chalcolithic era of this plain. Since the area of Silakhor plain is located in Boroujerd and Doroud counties and covers a large part of the north of Lorestan province, in this research, this plain is divided into two parts, north and south, the northern part of which is in Boroujerd and the southern part is in Dorud city. In order to study the situation of the settlements of Silakhor plain more accurately, its northern part in Boroujerd city has been chosen. 

Findings
The chronology of the Chalcolithic age of Silakhor plain and the east of Lorestan is also influenced by the chronology of the Gamasiab river basin and the Kangavar valley. The study and identification of the archaeological and historical monuments of this area has been done recently by Ahmad Parviz in 2006 and the review of the researchers in line with this research has been done in 2016.  In this study, according to Godin chronology, areas related to the chalcolithic age during three periods of old, middle and new era are studied. Sites are evaluated by the ArcGIS 10.3 software after being located on elevation maps through their Universal transverse Mercator (UTM).  In this evaluation, the altitudes of the area compared to the average altitude of the northern half of Silakhor plain and also their distance to the nearest rive, are examined. In the studies performed, it has been determined that 80 sites are belonged to the Chalcolithic age of the northern half of Silakhor plain, some of which include all three periods of old, middle and new Chalcolithic era.
 Of all 80 Chalcolithic Age sites in the study area, 25 sites are related to the old period. These areas are mainly distributed in the central parts and in the plains.  Most sites are at altitudes between 1,500 and 1,600 meters above the sea level.
Of the 80 Chalcolithic Age sites in the study area, 31 sites are related to the Cenozoic Ages. These sites, like the old period, are mainly distributed in the central parts and in the plains. Most sites are at altitudes between 1,500 and 1,600 meters above the sea level.
Of the 80 Chalcolithic Age sites in the study area, 42 are related to the Cenozoic period. These areas, like the old and middle periods of the Chalcolithic Age, are mainly distributed in the central parts and in the plains. Most sites are at altitudes between 1500 and 1600 meters above the sea level.

Conclusion
In this study, it was found that the number of old, middle and new sites of the Chalcolithic Age in the northern half of Silakhor plain (Boroujerd) are 25, 31 and 42 , respectively. This indicates that the Copper Stone Age in this area has developed in a growing trend (in terms of the number of settlement sites). Increasing the number of settlements in this area paves the way for future transformations in the next period (Bronze Age).  Therefore, the beginning of urbanization in this area has had a strong and evolving introduction to the Chalcolithic era.
On one hand, the study of maps prepared in ArcGIS software shows that the vast majority of sites in all three periods in the Chalcolithic Age are located at an altitude of 1500 to 1600 meters (average height of Silakhor plain is 1500 to 1600 meters) and in the area of Silakhor plain.  On the other hand, the analysis of the distribution map of the Chalcolithic sites of this area shows that the settlements of this period have been formed depended on the water resources (rivers).

Abstract
The Kermanshah Province is one of the significant regions studied by archaeologists, where numerous studies have been conducted so far. This research focuses on the examination of megalithic graves in the towns of Gilan-e Gharb and Sarpol-e Zahab in Kermanshah Province. Megalithic graves are among the burials that possess unique structures and architecture, which have been less explored and researched in Iran, particularly in the studied region. By studying these graves, it is possible to gain some limited knowledge about the culture, beliefs, and way of life of the people who owned these graves. The most important questions of this research are: What have been the architectural features of these graves’ structures? How has the distribution of these graves been and what pattern can be defined for this distribution? The research method is considered to be applied-historical in terms of its objective. The categorization of the form and structure of graves has been carried out descriptively. In this regard, while conducting field research in the area, an initial comparison of the typological data and relative chronology of graves was performed. Subsequently, using GIS software, an analysis and identification of the burial distribution pattern in the region were carried out considering various geographical factors. Based on these, variables such as elevation, slope, and rivers were analyzed. In general, the identified graves in this study are divided into two main groups: Cist graves and Cromlech ones, the latter encompassing various subtypes. Finally, studies and excavations have been conducted on these graves in the Caucasus, Anatolia, and northwestern Iran, which demonstrate the migratory lifestyle of the tomb owners. In this article, a portion of the cultural materials collected from the 2015 archaeological survey in the western towns of Gilan-e-Gharb and Sarpol-e Zahab in Kermanshah province is presented.
Keywords: Megalithic, Cist Graves, Cromlech Graves, Distribution Pattern, Typology, GIS.چ

Introduction
The word ‘megalithic’ refers to large stones, derived from the Greek word ‘Mega’ meaning ‘large’ and ‘lithos’ meaning ‘stone’ (Midgely, 2008: 23). In Persian and Iranian archaeology, it is referred to as a ‘large stone’. Megalithic graves are large, uncut stones that are sometimes formed with wood, soil, and other small stones (Shaw, 1999: 390). Studying the structure of Megalithic graves can play an important role in identifying the tribes that constructed them and is effective in dating these tombs, given the scarcity of ancient evidence and data. By conducting typological studies of these graves, their structural patterns can be reconstructed, and by comparing the surrounding areas, it is possible to date these tombs. Extensive studies have been conducted on megalithic graves in the north and northwest of Iran, but independent and specialized research on these tombs has not been carried out in Kermanshah province. Since the tombs in this area have not been methodically excavated yet, it is difficult to present a precise structural design of the tomb architecture. In this study, the typology will be based on the surface structure, and the dating of the tombs will be conducted through comparative studies. Research questions include the following: What are the types of megalithic graves? What are the characteristics of the architectural structure of these tombs? What is the distribution area for these species, and what pattern can be identified in this distribution?
In order to achieve the desired goals in this study, a set of field activities was performed, including sketching, photography, documenting and recording findings, and design. The research method used for classifying the shape and structure of graves is descriptive and also relies on comparative and library studies. This includes the collection of maps, reports, articles, and all useful information available in the region. The preparation and collection of the locations where the graves are situated are recorded using a GPS device. In the analysis of the distribution pattern of registered graves, a geographic information system (GIS) has been employed. In the study of the factors influencing the distribution of graves, various factors such as topography, water resources, elevation, and slope have been examined.
By identifying these factors, analyzing the data distribution pattern, and ultimately visualizing them on a map, it is possible to gain a partial understanding of why and how the areas are distributed and concentrated in the region.

Discussion 
Research on the structure of cemeteries and graves can be conducted using two different approaches: Firstly, typological studies are conducted based on the shape, dimensions, and materials of the graves. Secondly, factors such as the orientation of the graves, their proximity to one another, and their relationship to water sources, roads, and expanses in the cemetery are examined (Orlet, 1392: 93). The important point to note is that the structure of graves exhibits a distinct relationship with the geographical environment. In mountainous areas, for instance, there is often an abundance of large stones and slates that can be utilized in constructing graves. Consequently, there are variations in the shape and material of these graves, primarily due to the differing types of stones found in each region (Ibid, 1392: 107). The graves identified in this study are categorized into two groups: Cist graves and Cromlech graves.
 In the construction of cist graves, a pit was excavated approximately one meter deep from the ground, and its walls were lined with layers of large and small stones. Subsequently, after interring the deceased, the grave was sealed by placing large and extremely heavy boulders on top (Yukmen, 2003).
Cromlech graves are classified into following types based on the shape of the stone rings:
Mounded Cromlech refers to a type of grave that consists of one or more stone rings encircling a large stone tomb (Smith, Badalyan, Avetisyan, 2009: 106).
Paved Cromlech is characterized by its very low height from the ground, and its distinguishing feature is the scattering of small rocks on its surface (Ibid, 2009: 107).
Stepped Cromlech is defined by stone rings that encompass the central structure, exhibiting a vertical upward movement (Ibid, 2009: 108).
The elevation study of Gilan Gharb and Sarpol-e Zahab towns indicates that Sarpol-e Zahab has the lowest elevation at 540 meters, while Gilan-e Gharb reaches the highest altitude of 1340 meters that suggests a higher prevalence of graves in colder areas.
Through the examination of the influence of rivers on the distribution of graves and by referencing the water network map, it becomes evident that the graves tend to be situated in proximity to water sources. This distribution pattern signifies the significance of close access to water and further highlights the correlation between the location and distribution of graves within the river basin. Considering that the megalithic graves belong to the nomadic tribes, this proximity may be indicative of the convenience of accessing water for the needs of them and their livestock.

Conclusion
The typology of graves and their classifications in the study area of Sarpol-e-Zahab and Gilan-e-Gharb in Kermanshah province is based on comparative and comparative studies with megalithic graves in the north and northwest regions of the country. These graves are categorized into Cist and Cromlech graves.
The Cromlech species exhibit various structural forms within each range. Commenting on the shape of the landscape of megalithic graves is a complex subject that requires specialized studies and extensive investigations covering a wide area. When considering the geographic distribution of these graves, it is important to take into account factors such as the natural environment, topography, and the number of areas containing this type of graves. Furthermore, it is crucial to acknowledge the limited availability of extensive and specialized studies on these graves. Based on general findings from studies conducted on the distribution of graves, it is possible to identify certain areas that are centrally occupied with burials, while other areas remain devoid of any kind of burial. For instance, in certain areas of Sarpol-e Zahab, the absence of megalithic graves can be attributed to the scarcity of stones. Certainly, this can be justified by one reason: landscape manipulations in later periods carried out by farmers to level the land for cultivation. This is prominently observed throughout Sarpol-e Zahab due to its geographical structure and favorable conditions for agriculture. In relation to the correlation between water resources and the distribution of megalithic graves in this area, it is worth noting that the information obtained from GIS maps concerning the water bodies in the region demonstrates the close proximity of these graves to water sources. This proximity can be attributed to the practical utilization of fresh water sources by the nomadic communities, particularly for the purpose of sustaining their livestock. Hence, the architectural structure of large stone graves exhibits a distinct relationship with the geographical environment. In mountainous areas, the abundance of large stones contributes to a higher concentration of these graves in such regions. Based on comparative studies and the analysis of architectural features and structures of these large stone tombs, in conjunction with similar tombs found in the northwestern and northern regions of Iran, as well as in Anatolia, Caucasus, Russia, and Georgia, the period ranging from the ancient Bronze Age to Iron Age III can be attributed to megalithic graves. This classification is further supported by the presence of metal and pottery artifacts discovered within these graves.

The historical fortress of Aq-Qalih, a large and little-known structure in the Juvayn Plain of northern Khorasan, is tentatively attributed to the Mongol Ilkhanid period based on limited prior studies. However, extant Ilkhanid -period documents offer no confirmation of its existence. Therefore, the hypothesis of Ilkhanid construction relies solely on archaeological evidence and the dated inscription of the Aq-Qalih Mosque. This research seeks to establish the significance of Aq-Qalih as a midway settlement along Ilkhanid travel routes in northern Khorasan, utilizing historical documents and GIS analysis. Further, by comparing Aq-Qalih’s structure with contemporaneous structures in Mongol-influenced regions of China and Iran, this study assesses the hypothesis of Ilkhanid construction. The findings indicate Aq-Qalih’s strategic location along major Ilkhanid travel routes, with the Ilkhans’ and their successors’ annual visits increasing the likelihood of a midway settlement. Moreover, structural comparisons with Chinese examples like Shangdu, Daidu, and Yingchang, as well as Sultaniyya in Iran, reveal significant similarities, bolstering the hypothesis of Ilkhanid-era construction.

Abstract
South Rudbar Plain, with an area of more than 6000 square kilometers, is one of the important archaeological areas in the southeast of the Halil-Rood cultural area. This area, due to its favorable environmental conditions, including the permanent water of the Halil-Rood River, the fertile and vast plains, and the pasture heights in the northern part, as well as due to its geographical capacity and the communication route between Sindh and Sistan to Jiroft, was the foundation for the presence of human societies with the livelihood structures such as sedentary lifestyle and nomadic. As a result of two seasons of Archaeological surveys in South Rudbar plain during the last two decades, a number of ancient settlements were identified in this area. However, in these surveys, the focus is on pre-historic sites, while the sites of the Islamic era have not been studied deeply and completely, and only their GPS points have been recorded and incomplete descriptions of them have been provided. Therefore, answers have not yet been provided to questions about the role and influence of environmental factors on the distribution of Islamic settlements and the formation of livelihood organizations. In the following article, for the first time, the effect of environmental factors on Settlements of the Islamic era in Rudbar plain was studied with an analysis based on the findings of two archaeological surveys, documentary studies, and the preparation and interpretation of GIS maps. For this purpose, the settlements of Rudbar plain were divided into two time periods based on relative dating: “first to early middle Islamic centuries” and “late centuries (from the 10th century AH onwards)”. Then, environmental factors such as altitude above sea level, resources water, amount and direction of the slope of the lands, soil characteristics, and condition of roads in connection with settlement evidence were analyzed. The results of the research show that the most important factors affecting the formation, distribution, and organization of the livelihood of the Rudbar plain settlements in the Islamic era are the Halil-Rood River and the Aqueducts as the water sources in the peripheral parts, the trade route of Jiroft to Sind and Sistan, and the unevenness of the north and northeast for benefit from the potential of animal husbandry.
Keywords: South Roudbar, Environmental Factors, Distribution of Residence, GIS, Islamic Archaeology.

Introduction
The environment and its substrates are very important in examining the distribution pattern of ancient sites in a region. According to archaeological research, Rudbar plain has been a suitable place for human societies to live since at least the Copper Age (cf. Daneshi and Eskandari, 2016). This area as a commercial crossing (Yacoubi, 1963: 62) and one of the important areas of agricultural and livestock production (Sarhadi, 2017: 24), is very important in the archaeological studies of the Halil Road cultural area. However, the settlements of the Islamic era in the Rudbar plain do not have a share in the previous archeological studies and there are questions about this, which of the environmental factors and at what qualitative and quantitative level is effective in the distribution of settlements in the Rudbar plain in the south of Halil Roud cultural region during the Islamic era?
Based on this, the main purpose of this research is to investigate and analyze environmental factors affecting the formation and development of the Islamic settlements of Rudbar plain with a focus on geological features, altitude, water resources, and trade routes. Despite the numerous narratives of the early Islamic geographers about this region (see: Yaqoubi, 1963; Ibn Hawqal, 1966; Istakhari, 1994), no independent research has been done to identify and investigate the Islamic era settlements in Rudbar plain; and this issue shows the necessity and importance of this research. Also, the results of this research can help to understand the roots of the urban culture of this region in the early Islamic Middle Ages. 
The current research is historical research and a descriptive-analytical method was used. Research data has been collected by documentary and field methods. 

Discussion
The statistical database under study includes 53 sites and historical monuments, which are divided into two groups of settlement evidence, “first to seventh century AH” and “late Islamic centuries (Safavid and Qajar)” based on relative chronology (Tables 1 and 2). In order to explain the impact of environmental factors on the location of these sites and evidence, a geographic information system (GIS) has been used.

1. The effect of the height coefficient on the distribution of settlements
To explain the effect of height above sea level on the formation of the landscape and the distribution of the studied settlements, the height of the Rudbar plain is classified into eight classes (Figure 3, Chart 1). The largest number of cultural evidence representing the settlements of the Islamic era have been formed in this region at an altitude between 500 and 600 meters above the surface of open water, while only 4 sites have been found at an altitude of less than 400 meters above sea level. It seems that the large number of settlements at altitudes between 500 and 600 meters, which exactly covers the slopes of Rudbar Plain, is proof of the predominance of nomadic livelihoods in the Rudbar Plain during the Islamic era, and on the other hand, the small number of sites at an altitude of less than 400 meters can be analyzed in relation to the swampy condition of the Rudbar plain and the greater extent of the Jazmurian bed in the past.

2. The effect of water resources on the distribution of settlements
According to the maps obtained from GIS, most of the sites and evidence related to the settlements are located at a close distance from the surface water network, especially the Halil Rood River (Figure 4, Diagram 2). So, 17 sites, equivalent to 32% of the sites, were developed less than 5 kilometers away from Halil Rood River and under the direct influence of this water source. Another source of water is the Aqueduct. Among the sites of the Rudbar plain, especially those located on the edge of the plain and on the surface of the alluvial cone, were developed in connection with this water source (Figure 5).

3. The influence of the roads on the distribution of settlements
South Rudbar Plain was one of the important communication crossings of the Islamic era due to its location on the old communication and trade route from Indus to Jiroft (Yaqoubi, 1963: 62). According to the explanations of geographers about this ancient road, the current route of Rudbar to Iranshahr has been determined as a part of the aforementioned ancient route and the sites found have been investigated based on this route. As a result of this analysis, 17 sites with a significant linear extension in the west-east direction are located at a distance of 500 meters to 5 kilometers from this main communication road of the region (Figures 6 and 7, Diagram 3).

4. The influence of the slope of the land and its direction on the distribution of settlements
Based on the distribution map of sites and cultural materials related to the settlement of Islamic centuries in the Rudbar plain, we are facing a relatively flat land (Figure 8, Diagram 4). Regardless of the slope of the heights, we are facing a large and relatively flat plain where all the sites found were developed on a bed with a maximum slope of 5%. In fact, in terms of the relationship between the location of the sites and the slope of the land, no significant pattern can be defined. The settlements are located in various slope directions, including south, southeast, and southwest (Figure 9). Considering that the Rudbar plain is one of the tropical areas of the Halil River basin, it seems that the direction of the slope with a southern tendency is not logical. Therefore, it is clear that other environmental factors play a more important role in choosing a place of residence.

5. The effect of land use on the distribution of settlements
As a result of the land classification of Rudbar Plain based on the type of land use in the present era, four types of land use including pasture, agriculture, slopes, and the bed of Jazmurian Lake were investigated. Referring to the output map according to the type of land use, it seems that this factor played a decisive role in the distribution of settlements (Figure 10, Diagram 5). Considering the location of the settlements in connection with pasture and agricultural lands, the pattern of distribution can be interpreted in direct relation with the nomadic livelihood structure with a wider level and the agricultural structure with a smaller level during the Islamic era in the Rudbar Plain.

Conclusion
Rudbar plain is at the southern end of the Halil Rud cultural landscape and corresponds to the current city of Rudbar Jonoob. This region has been the foundation for the presence of human societies during the Islamic era due to its environmental talent, including the permanent water of the Halil River, fertile plains, and pasture heights, as well as being located on the ancient Sind-Jiroft trade route. Based on the analysis of settlement distribution and settlement evidence of the Islamic era and taking environmental factors into consideration, it seems that the cultural landscape of Rudbar plain during the Islamic era was mostly influenced by the variables of altitude, land use, and roads. As a result of the analysis, out of a total of 54 sites and settlement effects found, 50 points are affected by surface water sources such as Halil Rood River and aqueducts, as well as in connection with large pastures and small agricultural lands. Four other local evidence of settlement in the eastern end of the central plain, due to the lack of environmental facilities where they were formed, can only be explained in connection with the ancient road from Indus to Jiroft. Apart from these last four cases, the location of 13 sites/artifacts in the central plain of Rudbar, in addition to showing the relationship with other factors such as height and land use, has also been influenced by the road factor. In general, under the influence of the geographical and ecological factors of the Rudbar plain, the dominant livelihood of the people of the region during the Islamic era was formed based on providing resources through animal husbandry, agriculture, and trade.