MORFOMETRI DAERAH ALIRAN SUNGAI (DAS) SAUSU TERHADAP BANJIR DI BAGIAN HULU, KABUPATEN PARIGI MOUTONG

ABSTRACT

Parigi Moutong is one of the regions in the Sulawesi archipelago, especially the Sausu watershed which is prone to various flood events. The purpose of this study was to determine the flood-prone areas of the Sausu area using watershed morphometric parameters. The data used in this study include field surveys in the form of morphological data, namely lowland landforms, low hills, and hills with geomorphological conditions in the form of (Denudational), as well as physical weathering processes on rocks. and watershed morphometry data in the form of watershed area 127.1 k m2, length and width of the watershed 1.66 km, the order and ratio of river branches in the range of 1st order - 6th order with a value (Rb) 3 -5, river slope 0.005, drainage density (Dd) 0.32 - 0.90, the shape of the watershed bird feathers with a value (Rc) 0.4. The results showed that Sub-watershed 4, Sub- watershed 7, and Sub-watershed 8 has a fairly stambil ratio index value (Rb) 3 - 5 which indicates the character of the river with the rise and fall of flood water levels that take place quickly. By having a drainage density (Dd) 0.32 to 0.90 medium category with the characteristics of the river channel that passes through the lithology with softer resistance, so that the transported sediment will be greater. Then this Subwatershed is very potential for flooding in the study area.

Keywords: Morphometry, Watershed, Flood, Upstream, Sausu