Study of ocean water intrusion dynamics in the LISU River Basin Tanete Riaja district Barru Regency.

In Barru Regency South Sulawesi, several rivers have high salinity concentrations. This is due to the location of the river, which is directly related to the sea. The Lisu River Basin is one of the rivers that empty directly into the open sea. The watershed is used by the community in agricultural activities such as water for crop irrigation. However, the watershed has problems with seawater intrusion at the river mouth. In the rainy season, the flow of the river will be more so that the pollutants will be pushed into the sea by the large flow of the river. This can lead to a decrease in crop productivity along rivers that are intruded on by seawater. Meanwhile, in the dry season, the river will experience a decrease in water discharge to cause marine intrusion. This is because the river water discharge is not strong enough to withstand the tide of seawater. So, the river is indicated to experience sea water intrusion and will have a negative impact on plant productivity. The purpose of this study was to analyze the dynamics of river water quality vertically and horizontally as well as the relationship between water discharge and rainfall to the salinity level of river water. The method of this research is to take samples of river water from several stations that have been determined. A sampling of river water is done by taking river water samples on the river surface left, left of the riverbed, river surface right and right of the riverbed. Then measure the water quality. Based on the research on the dynamics of salinity of seawater intrusion in the Tanete Riaja sub-district, Barru Regency, it was found that the salinity level caused by seawater intrusion every week shows a dynamic pattern which means that it changes from time to time caused by several factors such as rainfall and discharge. [ABSTRACT FROM AUTHOR]