ABSTRACT
The Ica-Nasca region of the south coast of Peru, as part of the Northern Atacama Desert, is one of the most arid locations on the planet. Like most of the central Andean coast, this area is bisected by rivers that seasonally drain the Andean highlands and bring water for coastal irrigation. The arrival of water in these highly variable rivers is therefore vital to people’s livelihood. Today, populations concentrate along these thin strips of fertile land, and it is understandable that settlement surveys exploring past demography have also focused on river valleys and adjacent foothills. The assumption that past populations likewise would have selected river valleys for settlement is reasonable and has been confirmed by extensive surveys over the past half-century. However, the increasingly sophisticated techniques that create environmental reconstructions have recently revealed potentially significant climatic variations in the past that may have affected past hydrological conditions, resources, and human settlement location choices and opportunities. In this chapter I explore this possibility and present survey results that complement recent environmental reconstructions in indicating that the south coastal environment has not been constant and that modern conditions are a relatively recent phenomenon. As a result, south coastal populations have been faced with short-and long-term environmental changes and crises, and these challenges must be considered in examining past socio-political changes. Note that I am not reducing settlement location choices to environmental factors, but suggesting that through time these constituted shifting constraints on a dynamic settlement ecology. Various socio-environmental criteria for choosing settlement locations-in addition to subsistence imperatives-included, at different times: cycles of conflict and alliances, participation in religious movements, culturally constituted landscape perceptions, mass migrations, emergent leadership, and population growth.
