The Effect of Tidal Influence on the Palingkau Swamp Irrigation Area SP1, SP2, SP3

¹ Master Student, Civil and Environmental Engineering Department, Universitas Gadjah Mada, Indonesia
² Department of Civil and Environmental Engineering, Faculty of Engineering, Universitas Gadjah Mada, Yogyakarta, 55281, Indonesia

^* Corresponding author: rjayadi@ugm.ac.id

Abstract

Water supply and drainage in the Palingkau Swamp Irrigation Area, Kapuas Regency, Central Kalimantan Province, is affected by the tides of the Kapuas and Kapuas Murung Rivers as water sources. The flow reach into the irrigation area depends on the tidal flow energy. Insufficient flow energy can lead to dead water zones in several channels, as water cannot be discharged into the handil outlets. This study aims to assess the location of potential occurrence of water dead zones through hydraulic simulations based on channel geometry and the observed tidal water levels at two locations simultaneously. The hourly water level data was recorded simultaneously using CCTV at two points for 14 days. Unsteady flow simulations were modeled using the HEC-RAS application to determine the dominant influence of the tidal water sources and the presence of dead water zones. The simulation results indicate that the tidal influence on the Palingkau Swamp Irrigation Area is more dominant from the Kapuas River. The tidal amplitudes of the Kapuas River and the Kapuas Murung River are 2.18m and 1.38m respectively. Several water dead zones were found in collector channels, requiring efforts to enhance water management through more detailed hydraulics modeling.