Type of mixing confluence between Mahakam and Karang Mumus Rivers based on temperature and salinity distribution tidally

Abstract

Observations of physical oceanographic parameters including temperature and salinity were carried out in Estuary Mahakam and Karang Mumus Rivers, on July 8, 2018, and July 14, 2018, to determine the vertical distribution patterns of temperature and salinity used to identify the type of estuary confluence Mahakam and Karang Mumus Rivers. Observations were conducted at 9 points and 11 points when the neap tide and the spring tide conditions were in the estuary area to enter the Karang Mumus river at the surface, middle and bottom layers. Temperature and salinity parameters were measured using the CTD Minos sensor system equipment. X PDC-B0900 which can simultaneously record profiles of temperature and salinity parameters lowered to the bottom of the water while the point position was determined using GPS. The results of the observation of temperature distribution showed that in the Estuary between Mahakam and the Karang Mumus Rivers did not have a thermocline layer. This was because of the depth of the water under study including shallow water. Salinity distribution was obtained with a relatively homogeneous salinity towards depth water. Homogeneous salinity is an indication of a well-mixed vertical process between seawater and freshwater.