Kirsten Vacca NRS 509 December 6, GIS and Archaeology

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1 GIS and Archaeology Kirsten Vacca Archaeologists have developed multiple uses for Geographic Information Systems (GIS) since the inception of this groundbreaking technology. Applications for GIS research in the field have evolved alongside the technology over the last several decades. From site identification to artifact analysis, GIS technology has proven useful in almost every stage of an archaeological investigation. However, a great deal of controversy surrounds its application with regards to methodology and theory. Numerous professionals that adhere to the post processual theoretical framework fear that GIS removes the human aspect from an archaeological site and produces inaccurate analyses of geographically significant areas. This essay reviews the positive implications of GIS technology in the field of archaeology as well as drawbacks identified as inherent in the system. The conclusion will cover possible remedies and future prospects for GIS applications. Although occasionally controversial, Geographic Information Systems prove invaluable to archaeologists in that nearly all data collected in the field can be geographically referenced. This leaves the researcher with an enormous amount of spatial data to organize, categorize, and analyze (Weatley 2002:3). The collection process regarding this data begins with the initial survey conducted with the intent of locating a cultural site. Maps created through GIS programs are currently most intimately involved during this stage of an archaeological investigation, as they serve multiple purposes. Analogous to other sciences, researchers working on an archaeological excavation seek to answer specific questions, with the initial inquiry being where? where are the ideal conditions for this site to be located, where are the majority of surface cultural remains, where are similar sites in the region etc. (Neubaur 2004:160). The answer to each of these questions will assist the archaeologist in finding an appropriate location to begin the investigation. In order to establish a specific geographic area of study, archaeologists can utilize features of GIS such as terrain modeling as well as soil, geographical, and hydrological maps (Djindjian 1998:27). Such maps can also include previously excavated sites in the region as well as important artifacts found in order to gain a better perspective on prime locations. The endless amount of environmental data available through this system, accessed and applied through overlay or other basic procedures, can quickly generate endless environmental variables, such as slope, and aspect (Whitcher 1999:25) that provides invaluable details when locating potential sites. While many archaeologists still prefer to survey on foot, walking the land in search of potentially promising indications of cultural deposits, GIS (along with remote sensing through aerial photography) provides an additional tool to use when analyzing possible locations and allows researchers to easily include areas that are difficult to access. An important aspect of survey technique, recording and documentation has immensely improved with the application of GIS technologies. Historically, archaeologists have relied on hand drawings of significant areas, utilizing conventional tapes and scale bars (Bryan 2010:26). Aside from the previously mentioned issue of access, such methods also rely on the drawing standards of the surveyors and their ability to interpret detailing (Bryan 2010:26), which introduces potential for human error. Manual methods of survey and documentation remain valuable, as they allow direct contact with archaeological remains and therefore an

2 interactive analysis process. However, mistakes due to human error can result in inaccurate recordings and interpretations. Total stations and GPS devices allow for increased accuracy in mapping located sites. Although more expensive than traditional methods, such technique saves valuable time (as invasive archaeological excavations are incredibly time consuming) and allows for comparison between existing sites in the region (Bryan 2010; Bevan and Conolly 2004). Additionally, the use of digitized photography from aerial survey combined with transit information and GPS coordinates provide an accurate scale of the region that is critical when beginning an invasive research project. Due to the expensive nature of total stations, aerial photography, and certain GPS devices, several excavations utilize photography from digital cameras as a record of the area, acquire coordinates from handheld units, and digitize handdrawn scale maps as a documentation of the dig site. Although this does not require the latest equipment available in the world of spatial technology, digitized maps drawn to scale still allow for spatial referencing of artifacts that can then be incorporated into GIS maps. Several archaeological research projects predominately require survey of the site, as discussed above. One particularly prolific example, archaeology visibility studies, seeks to research and analyze the perception of the landscape surrounding a culturally significant area. Visible features of the landscape are particularly important in this analysis, and are often recorded on viewshed maps in GIS (Lake and Woodman 2003). For example, the researcher will produce a viewshed map originating from the coordinates of a particularly important monument in the area of study. From the subsequent results, the researcher can analyze the landscape for possible features (natural or otherwise) that seem to interact with the point of interest. Although visibility studies do not necessarily require invasive action, survey combined with excavation technique is perhaps a more common method applied to archaeological research questions. When used properly with adequate information regarding scale relative to the site of interest, GIS can also assist in the excavation process. Although in situ explorations rely on manual labor rather than technological advances, GIS technology is functional in recording the coordinates of the location where major artifacts and/or features are uncovered. Doing so allows for identification of clusters within the material remains, which produces data sets that researchers apply interpolation methods to in order to better understand patterns of distribution on and around the site (Bevan and Conolly 2004:130). This leads us to the analyses of archaeological remains, the final step in any investigation. As previously stated, interpolation methods applied to the distribution of material remains allow for a detailed analysis of artifact locations in relation to space at an archaeological site. This can produce important information regarding use of space, particularly for landscape archaeologists. Other methods of analysis involving GIS also play an important role in the final stages of archaeological investigations. Bevan and Conolly (2004) demonstrate the possibility of identifying similarities between features that could potentially assist in future identification of sites. For example, while researching on the island of Kythera, Greece, Bevan and Conolly (2004) discovered that a rise of degrees in hill slope implies a change in field management strategies (127). Additionally, the aforementioned viewshed maps play an important role in analysis, as archaeologists strive to understand the viewpoint of the original inhabitants in their selected area of research. Such maps can assist in the deeper understanding of the cultural perspective in relation to the surrounding environment, which can in turn play a

3 vital role in the interpretation of the site as a whole. The examples of predictive modeling and perspective maps discussed here are merely a brief overview of the potential analysis capability GIS technology possesses. Although easy to become inundated with the impressive applications of GIS to archaeological method and analysis, one must remember important limitations of the software as it relates to archaeology. Primarily, professionals in the field are concerned with neglecting personal experience in favor of technological advancement. This is a particularly valid and important critique in that the experience of landscapes is multi sensual they can be touched, smelled, and heard as well (Whitcher 1999:19). Although Geographic Information Systems are able to include massive amounts of environmental data, they lack the ability capture the various aspects of perception that are so important in an archaeological investigation. GIS applications are often seen as essentializing when applied to landscapes (as well as perceptions of landscapes) and devoid of the human experience. Archaeologists have recently begun to include this aspect of perception in their analysis of landscape, as they believe it important when attempting to properly understand the purpose of the societal organization. As previously discussed, viewsheds assist with this, but cannot capture the additional experiences that Whitcher (1999) mentions in his article. Viewsheds are further essentializing in that features visible from a certain point are included in the final map, but it remains difficult to ascertain if such features are interpretable from large distances (Lake and Woodman 2003). Additionally, viewshed maps are unable to display change in the appearance of the landscape as an individual walks from one point to another, a detail Lake and Woodman (2003) among other archaeologists find quite important in visual studies. In essence, the aforementioned limitations hinder the understanding of visual space, especially when movement, and therefore change, has been identified as a key element in visual perception (Lake and Woodman 2003). Ultimately, use of GIS in the analysis process is seen as supporting environmental determinism, an idea widely disputed in theoretical circles. Another challenge of the application of GIS in archaeological analysis is more of a technical issue and essential to the very nature of archaeology. Mapping with GIS software allows for 3D (realistically 2 ½ dimension) modeling, but cannot account for the temporal aspect of an investigation. As Djindjian (1998) discusses in his article on the progression of GIS in archaeology, this is one hurdle that may be difficult to surpass archaeologists need a 4D graphic and cartographic product (28) that can account for change in the landscape over time. Although this is an early article, the concern regarding the lack of ability to account for temporal characteristics of research projects (notably an important, if not the most important aspect of an excavation) is repeated time and again in articles written over the past thirteen years. The use of GIS technology in archaeology has progressed immensely since its advent. As Wheatley and Gillings (2002) exemplify in their book on the subject, the applications for research questions are numerous and include mapping discarded bone debris around a hearth to analyzing the hierarchy of settlements within a region (4). Although the limitations of GIS in research and excavations have been identified, academics are diligently working to mitigate the issues. As recently as 2009, Warden calls attention to the issue, stating, technology at this point is outpacing methodology and challenging academic and professional practice to keep up (8). Strides have been made, most noticeably by Llobera s (2003) work

4 with visualscapes in addressing the issue of dynamic perception; Lake and Woodman (2003) in creating a function for GIS packages that can calculate movement into perspective maps; and Barcelo who, in 2005 presented a paper detailing his work with developing a system that could account for four dimensions in what he termed a temporal stack ( a display of multiple temporally differentiated 4D scalar maps in a single window (8)). As an increasing number of archaeologists are educated on the use of GIS technology, the methodology will improve as will application in the field. Ultimately, archaeologists must remember that cartographic representations are not the final analysis of cultural remains, but merely a tool in the arsenal of analytical materials that professionals can use in order to better understand landscape and the relationships with cultural development. With this in mind, GIS technology combined with remote sensing will continue to contribute to preservation of cultural heritage worldwide. Annotated Bibliography Bevan, Andrew and James Conolly GIS, Archaeological Survey, and Landscape Archaeology on the Island of Kythera, Greece. Journal of Field Archaeology 29: In what seems like a response to criticism of the application of GIS to Field Archaeology research models, Bevan and Conolly address potentially positive impacts of the technology in this article. Believing that GIS can be a useful analytical tool, the authors illustrate applications of the technology utilizing their current research on the Island of Kythera, Greece. The initial question focused on field systems in the area, and through the use of terrain modeling, they were able to identify a pattern in slope related to field use in the area. Although Bevan and Conolly s second hypothesis (inverse relationship between ground coverage and artifact recovery) was not substantiated through further research, they did find that by geographically referencing artifacts, they were able to analyze clusters and therefore better determine use of space. With the previous information, Bevan and Conolly suggest future applications related to understanding site formation. Although the researchers are honest about the shortcomings of GIS, they present viable applications that are refreshing to see when most landscape archaeology papers merely critique the system. Bryan, Paul Metric Survey for Preservation Uses: Past, Present, and Future. APT Bulletin 41: In this paper, Bryan discusses the advantage of utilizing GIS and remote sensing methods as part of archaeological survey technique. He initially addresses specific tools such as laser scanners and GPS units, and subsequently illustrates the advantages of such technology. Bryan argues for a combination of old and new techniques in order to properly preserve cultural heritage. He suggests that newer technology allows for increased access and accuracy while older methods offer personal experience invaluable to the analysis and recording of a site. This was an incredibly informative article due to its succinct explanation of new technologies as well as their advantages and disadvantages in the field of archaeology. Djindjian, F GIS Usage in Worldwide Archaeology. Archeologia e Calcolatori. 9:19 29.

5 Djindjian wrote this article in 1998 with the intent of exploring the diffusion of GIS technology throughout the world and within archaeology over the past decade (from ). He begins with a detailed discussion of computer sciences that led to the advent of GIS technology. Following this section, Djindjian describes several implications of GIS on the world of archaeology, including use in salvage archaeology and Cultural Resource Management (CRM) two of the biggest users today due to funding availability. The author then lists numerous statistics regarding use of GIS by project and by country. These statistics prove interesting, as they exemplify the evolution and spread of the technology throughout the world. Djindjian then describes numerous applications of GIS software, including specific uses for raster and vector packages. The paper concludes with recognition of the importance of GIS in cultural heritage preservation as well as recognition of theoretical debates and shortcomings of GIS programming related to archaeology. Although several years old, this article remains interesting for numerous reasons; the simple descriptions of the technological development are informative, and the debates regarding theory and methodology as well as his critique regarding lack of accommodation for temporal analyses are still applicable in today s world. This proves that an immense amount of progress in GIS application is yet to be made. Lake, Mark and Patricia Woodman Visibility studies in archaeology: a review and case study. Environment and Planning B: Planning and Design 30: Lake and Woodman explain in an informative manner the drawbacks of applying GIS technology to visibility studies in their article regarding research on societal monuments. Although the two authors firmly believe in the usefulness of the software, they are upfront about the shortcomings, implying that GIS is currently only useful to a point when studying perception and change over time. Following the brief overview of the methodology involved in visibility studies, Lake and Woodman discuss possibilities for the integration of GIS technology in this process. Although admitting the potential usefulness, the researchers list numerous critiques that admonish the technology for its propensity to support functionalist and environmental determinist views of landscape due to the lack of environmental interaction inherent in the program. Lake and Woodman proceed with a case study that is intended to exemplify methodological developments needed so that GIS can better contribute to visual studies. The case study leads the authors to describe a function that can potentially be added to GIS programs similar to viewshed, allowing users to include movement through the landscape as a variable of calculation. While identifying current drawbacks, the authors wonderfully demonstrate the potential of GIS in their particular area of interest. Llobera, M Extending GIS based visual analysis: the concept of visualscapes. International Journal of Geographic Information Science 17: This article focuses on new developments in GIS application with regards to visual analysis. Llobera begins with a critique of GIS analysis, stating that the operations prove inadequate when studying human perception and human space interaction. The author believes that

6 additional functions must be developed in order to rectify the gap between GIS analyses and cognitive/perceptual factors. Llobera then introduces the term visualscapes, which he utilizes throughout the article as the term for multiple representations/structures of visual space that can be represented through GISc in his theory. The article proceeds to explain complicated mathematical equations that can calculate these multiple representations and produce an increasingly accurate map based on visual perception. Llobera describes the problems with current functions, such as viewshed maps, and alternatively suggests future possibilities using visualscape methods. This article identifies the issue with basic GIS functions in incorporating an individual s interaction with the landscape. Llobera s extension of GIS based visual analysis (as the article title implies) incorporates perception details such as movement and amount of visibility. His primary focus is the active nature of perception, but Llobera also recognizes the issue with incorporating the temporal aspect and attempts to rectify this through use of visualscapes. Although technical at times (potentially difficult to understand without proper knowledge of GIS concepts), this article follows the methodological language with an in depth explanation of procedures that allows for complete comprehension and offers excitement for the future of interactive GIS analyses. Neubauer, Wolfgang GIS in Archaeology the Interface between Prospection and Excavation. Archaeological Prospection 11: Neubauer describes GIS as the link between archaeological prospection (survey) and excavation in this 2004 article. He views GIS as an instrument in preservation of important cultural material and believes that with proper application, archaeologists can analyze remains without performing invasive excavations. Neubauer begins with basic advantages of the technology, insisting that excavations are time consuming and irreversibly destructive although occasionally necessary. GIS mapping can alleviate much of the need to dig test pits in order to investigate historically significant sites. Due to the fact that archaeologists deal primarily with spatially referenced data, he argues that GIS allows for relationship analyses that can better preserve the site. Additionally, the author argues for GIS and remote sensing technology as an increasingly accurate method of measuring scale on and off site (which, again, assists with better preserving remains through accurate records). When excavations are necessary, the uncovered material can be recorded in GIS maps as a permanent record, which will assist in future analyses of the historical site. Ultimately, Neubauer s goal is noble, in that he is primarily concerned with the best method of preservation and believes that with the proper combination of archaeology and GIS technology, the profession and society as a whole will positively benefit. This article lacked recognition of the disadvantages of GIS application in archaeology, but ultimately provided a useful assessment of the reciprocal relationship between survey and excavation techniques. Warden, Robert Towards a New Era of Cultural Heritage Recording and Documentation. APT Bulletin 40:5 10.

7 In this review of current technological advances, Warden discusses the methods most applicable to the field of archaeology. Although he primarily focuses on remote sensing methods including an incredibly interesting documentation technique utilizing LIDAR he does discuss possible implications of GIS technology. One of the main implications mentioned is the improvement in geographic referencing through use of total stations and GPS units. Although Warden acknowledges the role and importance of manual recording, he states that recent technology offers accuracy that will allow for better preservation of historical features (especially due to the fragile nature of many structures). He seems to think along similar lines as Neubauer, citing increased efficiency as well as relief from labor intensive exercises. However, the most interesting point in this article relates to our ultimate obsession with new technological tools Warden states that in the effort to keep up with the latest technology, we tend to lose site of the heritage, which should be the focus of any investigation. In a completely accurate and honest observation Warden observes that the discipline as a whole should not allow the technology to drive the research, but vice versa. Technologically driven study is evident in that methodology has neglected to keep up with new advancements and therefore many professionals are improperly using GIS maps in analyses procedures, resulting in inaccurate data. This is an incredibly important reflection, as cultural heritage should always remain the central focus of archaeology.

8 Additional References Kirsten Vacca Barcelo, Juan A Multidimensional Spatial Analysis in Archaeology: Beyond the GIS paradigm. Unpublished paper presented at The GIS Symposium: Reading the Historical Spatial Information in the World Studies from Human Cultures and Civilizations based on Geographic Information System. Kyoto, Japan. Whitcher, Robert GIS and Landscapes of Perception, in Geographical information systems and landscape archaeology. Oxford: Oxbow Books, pp Mediterranean landscape archaeology 3. Wheatley, David and Mark Gillings Spatial Technology and Archaeology: The Archaeological Applications of GIS. New York: Taylor & Francis, Inc.

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