The transition from semi-mobile hunters and gatherers to sedentary, food-producing villagers is a crucial process in the development of human culture. This process, designated as Neolithization, was first documented in the so-called Fertile Crescent of the Near East, an area forming a gentle arc from the Dead Sea to the Iranian plateau, flanked by Lebanon, Amanus and the Eastern Taurus Mountains. The Fertile Crescent was the home of the wild forms of first cultivated plants, such as emmer, einkorn and barley, and first domesticated animals, such as sheep and goats (Nützel 2004). These resources and favourable environmental conditions are considered to be initial factors for the transition to sedentism in the Fertile Crescent (Bartl 2004, 29-38).

As sedentism continues to be an important phenomenon in Neolithic research, one of the main objectives of this dissertation was to investigate aspects in the landscape that motivated early settlers to build sedentary communities. Furthermore, one additional goal of this analysis was to study changing preferences for the choice of different settlement environments within the development of Neolithization. To achieve this objective, it was necessary to reconstruct the ancient landscape, settlement distribution in the landscape, and possible settlement functions. Therefore, a database of all the archaeological information concerning the Neolithic period was created for the area of study focusing on Upper Mesopotamia. Furthermore, archival records, such as pollen analyses, were used to reconstruct vegetation and land use history. In addition, animal remains recovered during field work were investigated in order to reconstruct faunal life, noting that specific faunal species can be related to certain environments. Geomorphic analyses were also examined for the purpose of understanding formation processes and the landform history of landscapes. Remote sensing was used to gain further spatial information and combined with the data mentioned above. Subsequently, the data was entered in a Geographical Information System Database. However, it was still essential to adjust this data through field work and for this reason a survey was conducted.

Most of the initial data for the survey was collected from published work. The preliminary data was investigated to create a major database, including information on architecture, lithics, small finds, flora, fauna, and geographical information of all Neolithic sites in the area of interest. Thereafter, material from unpublished sites was studied in the laboratory of the Department of Prehistory at Istanbul University and included in the database. A survey with a documentation of tells (settlement mounds) in the area of interest was then conducted, aiming mainly at an accurate measurement of the sites and a systematic photographic documentation of the landscape surrounding them. This was especially important for unpublished sites, whereby the primary task entailed their recovery. Furthermore, it was a research objective to locate potential archives of geological and geomorphic data. After finishing data collection and processing phases, the database was incorporated into the GIS as mentioned above. Maps, including digital elevation models and satellite images, were processed in order to recognize and determine bedrock types, minerals, recent vegetation, and soil types. Additionally, first statistical analyses were conducted concerning settlement characteristics.

Among these analyses, the spatial distribution of 202 sites in an area of 167.313 km2 was initially evaluated. Comparing the site distribution with the investigated survey area it became clear that more than half of the sites (52,7 %) were discovered as a result of dam construction or irrigation projects. Therefore, the analysed data does not reflect the entire original site distribution in the area of research, but is more focused on the riverbanks of the Euphrates and the Tigris and surrounding tributaries. As a result, the circumstances for the discovery of each site were documented. Further analyses were first conducted with all the sites within the vicinity of dam construction and later on with sites not detected due to dam construction projects to see whether there are differences regarding preference patterns.

After investigating the general picture, three different types of time slices were created according to the accuracy of the data from the sites. The most accurate time slice is based on radiocarbon dates of excavated areas, although only 18% of the sites had been excavated and provided respective datings. In other words, this time slice is the most accurate type for which small timescale changes can be recognized. However, it reflects the least general picture. The second time slice is based on data from intensively studied lithic and ceramic developments of excavated and surveyed sites. This time slice provides an accuracy of 5 different periods for which developments could be studied. 72% of the sites are included, reflecting a much more general picture. The last and broadest time slice differentiates only two different periods ? the Pre-Pottery and the Pottery Neolithic. Accordingly, all the sites are included in this time slice. Successive spatial analyses of the material culture have been conducted for all three time slices in order to see whether changing accuracies or time scaling reflect different trends.

In order to identify possible site functions, architecture was processed. From the analysis of special and domestic buildings, lithics, as well as small finds of non-daily usage it was possible to distinguish between sites with high ritual functions and sites with more domestic functions. Furthermore, some sites were identified as resource exploitation sites when regarding the amount of tools, debris, cores, settlement size, and the absence or presence of domestic architecture. Another issue for site function analysis was the calculation of the degree of domesticated animals and cultivated plants.

Spatial analysis of the sites (with reference to their dependence on topography), old streams and river basins, bedrock types, minerals, and soil types were carried out for the different time slices mentioned above to see whether there are general trends from the Early to the Late Neolithic in environmental settlement preferences. Furthermore, these spatial analyses were carried out for the different site types mentioned above with respect to the circumstances of their discovery.

One result of these analyses addresses, for example, ritual sites of South East Anatolia situated at high altitudes: some of these were found on high peaks of mountain ranges next to limestone resources which had been quarried (Moetz/Çelik in press). On the one hand, these sites were not recognized before the last decade due to their topographical setting and, on the other hand, since most archaeological work was bound to river valleys as mentioned above. Although such sites were not restricted to hilltops, if they existed in valleys they were nevertheless difficult to recognize because of the impact of geomorphological processes and human resettlement which conceal the sites. With the beginning of plant and animal domestication, these special sites also became less important until they disappeared altogether at the start of the Pottery Neolithic.

Further results concerned settlement sites where preferences for specific soil types and low precipitation have been detected. In addition, settlements tended to be located at low areas with almost no slopes. Within the development of agriculture and the domestication of animals, these tendencies seem to increase over time.