Physical environment and subsistence

The Manambu are a people of the East Sepik Province of Papua New Guinea, and live along the section of the Sepik River that flows between the Hunstein Mountains and the Washkuk Hills (see Map 1). Here and there along these forty-or-so kilometres of the Sepik, the hill-slopes abut directly onto the river; but elsewhere they recede and the Sepik, varying in width between three and seven hundred metres, flows in a broad meander bed and is subject to frequent shifts in its course. Where the river curves, the inner banks usually consist of mudbanks, while the outer ones rise vertically to some five metres above low water level. Both are lined with tall, dense stands of wild sugarcane (Saccharum robustum) and Phragmites reed. During the wet season, the river may rise five or six metres, flooding large areas of the surrounding plain.

The immediate meander plain of the river consists of complexes of parallel and intersecting natural levees, with pandanus and swamp-grasses as the predominant vegetation. The higher levees may also be lightly forested. Here there are also ox-bow lagoons – detached meander loops of the river – covered with floating grasses, water-lilies and other aquatic vegetation. Behind the levees lie large areas of back-swamp, much of which is permanently flooded to form shallow all-season lakes. Further inland, the terrain changes to swampy forest with sago-palm in the understory; parts of this may be flooded for a short time each year.