Mahakam River
Mahakam River Upstream of Long Iram the river is flowing in tertiary rocks (Voss, 1983). Between Long Iram and Muara Kaman (middle Mahakam area) the river is flowing in quaternary alluvium, while in the downstream area between Muara Kaman and the coast including the Mahakam delta, tertiary rocks are again present. The presence of the large delta is explained by the formation and rejuvenation of the hilly region near Samarinda. The ITCZ drives the Indo-Australian monsoon phenomena which influence the regional climate including the Mahakam catchment. In December, January, February the concentration of high pressure in Asia and low pressure in Australia make the west wind blows in Indonesia (west monsoon). In June, July, August concentration of low pressure in Asia (summer in northern hemisphere) and concentration of high pressure in Australia make the east wind blows in Indonesia (east monsoon). Due to the global air circulation and the regional climate mentioned above, the Mahakam cat...