STUDY AND IDENTIFICATION OF THE HYDRAULIC CHARACTERISTICS OF UNDERGROUND RIVER

• Main Author: Parinata, Bangun
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/46343
• Institution: Institut Teknologi Bandung

The existence of karst area in Indonesia nowadays is considered to have a strategic value. The karst topography itself is a natural structure that not only unique but also have a great potential, especially in the field of water resources. The hydrological topography is very unique and different because it constructed from limestones that inflict the surface water to become limited. Otherwise, there are so many water channel underground forming a conduit and a gap. The main purpose of this study is to find the difference of surface river and underground river based on the hydraulic characteristics by identifying the connection between amount of the discharge and rainfall of the river. This study started by collecting the secondary data from literature, then surveying the location of the study. To identify the difference between surface river and underground river, comparison between these two is needed. The comparison involved are the cross section of those two rivers and the curve that contained two factor that are the annual water discharge and rainfall intensity. The location of the study is in Cijulang River, Pangandaran Regency, West Java. The Cijulang Watershed has more than 30.000 hectare that flows in three sub-district in Pangandaran Regency. Then, the data obtained were the annual water discharge of Cijulang River and the annual rainfall of the Cijulang watershed. This data produce the curve that can be compared between those two factor and can be seen that there was a time lag between the highest rainfall to the highest water discharge in the underground river. After the analysis, can be concluded that there were differences between the surface river and underground river that can be seen on the cross sention formation and the presence of big time lag on the underground river that can’t be found on surface river. Later, the water quality of the Cijulang River that tested is not qualify as “clean water” based on Permenkes 492 year 2010, because of these water testing did not meet the regulation at some point.