NYAME AKUMA No. 64 December 2005 24 GIS and Landscape Archaeology: Delineating the Possible Long- Term Environmental Effects of Pastoralism on the Laikipia Plateau, Kenya Michael Causey Institute of Archaeology 36 Beaumont Street Oxford, OX1 2PG United Kingdom E-mail: michael.causey@arch.ox.ac.uk Paul Lane British Institute in Eastern Africa PO Box 30710, GPO Nairobi, Kenya E-mail: pjlane@africaonline.co.ke KENYA Introduction Conservation policies across Africa often lack important information pertaining to long-term envi- ronmental change and patterns of land-use (e.g. Brockington and Homewood 2001; Gillson and Lindsay 2003; Leach and Mearns 1996). Without this requisite knowledge, it is difficult for policy-mak- ers to implement effective land-use management schemes to protect both wildlife and the ecological patterns that sustain them. At the same time, local concerns regarding ancestral rights to land, natural resources and other kinds of common property must also be addressed, along with broader desires for poverty alleviation and sustainable development. Demographic expansion, combined with disparate new land-use practices, earlier inequitable decisions of land allocation and increased modernity, among other factors, have all helped create intense pressures which, especially in semi-arid regions, may exacer- bate erosive processes induced by human activity. Not surprisingly, then, debates over land-use in many parts of Africa are highly contested. In an attempt to better understand the relative contribution of the processes and events behind cer- tain contemporary land-use issues, the British Insti- tute in Eastern Africa embarked upon a three-year research project in 2002 entitled Landscape and En- vironmental Change in Semi-Arid Regions of East and Southern Africa: Developing Interdisciplinary Approaches. The project was funded by the British Academy, with additional logistical support and serv- ices provided by many of the property owners and managers where fieldwork was conducted. The study areas included the Laikipia Plateau, Kenya; Malilangwe, Zimbabwe (Thorp 2004) and the Kabwe area of Zambia. The overall focus was on the long- term environmental consequences of human activi- ties in these regions, with the aspiration that by com- bining the results of ecological, historical, archaeo- logical and anthropological studies, fresh insights might be provided for current land-use policies in these and other comparable regions of Eastern and Southern Africa. The Laikipia Plateau The Kenya element of the project was princi- pally concerned with reconstructing patterns of pastoralist activity and their long-term environmental effects. Laikipia was chosen for at least three rea- sons. First, prior to the commencement of the project, systematic archaeological studies were limited to surveys and excavations in the area around Kisima Ranch during the 1970s (Siiräinen 1977, 1984) and a more recent analysis of site distribution in the Mukogodo Hills (Dickson et al. 2004). A primary objective was therefore to augment the level of archaeological knowledge about the study area. Second, the geographic position of the Laikipia Plateau on the eastern side of the Great Rift Valley, immediately south of the Lake Turkana Basin, likely made it a critical zone for the southward expansion of pastoralism some four to five millennia ago. Traces of Elmenteitan and later pastoralist remains were noted by previous researchers, and the area is known from oral traditions and documentary sources to have been a centre of pastoralist activity during the 18th and 19th centuries (e.g. Galaty 1991; Sutton 1993; Waller 1979). However, neither the intensity nor the nature of early pastoralist activity (i.e. that conven- tionally associated with the East African Pastoral Neolithic) on Laikipia, or the subsequent transfor- mation and/or replacement of these groups during