The Harappan Civilization was wide ranging geographically (Figure 1). Cultural influence extended from the highlands of northern Pakistan to the Arabian Sea, from the foothills of Baluchistan and central Afghanistan to the Aravalli Hills and the Yamuna River of central India. Primary settlement was on the alluvial plains of two river systems: the Indus, and the Ghaggar-Harka. Both rivers flowed from the Himalayas to the Arabian Sea. These rivers formed vast floodplains with regular flooding which provided moisture and fertile soil for pastoral and agricultural activities on a large scale (Kenoyer 1988).

The direct and indirect exploitation of periphery environments enriched the Harappan Civilization. The foothills and upland valleys of Baluchistan supplied timber, copper, stone, and precious minerals (Asthana 1982). Copper, tin, silver, lead, stone and precious minerals were obtained from the Aravalli Hills of the southeast (Asthana 1982). The Gujarat Plains served as a bread basket for urban centers such as Harappa, Mohenjodaro, and Kalibangan (Kenoyer 1988). Fish and shell were available from the many rivers of the area, the Makran Coast and the Arabian Sea (Kenoyer 1988). The northern gallery forests supplied timber in great quantities for building and fuel (Kenoyer 1988).

Disruption of the agricultural base possibly caused by a river course change due to sedimentation and/or tectonic movements may have led to the collapse of the Harappan Civilization (Kenoyer 1988). At about 1500 B.C.E ., the Saraswati, Ghaggar, and Hakra Rivers were captured by the River Yamuna which shifted their drainage from the Arabian Sea to the Bay of Bengal (Kenoyer 1988). The Sutlej River was captured at this time by the Indus which shifted to the east (Kenoyer 1988).