EFEKTIVITAS KOLOM PASIR PADA WADUK RESAPAN SEBAGAI PENYANGGA INTRUSI AIR LAUT

Abstract

Excessive groundwater extraction, causing the occurrence of water vacancies under the surface of the soil,
causes the sea water pressure to land larger, resulting in sea water intrusion. To support seawater intrusion, one way that
can be done is by adding groundwater using a sand column placed at the bottom of the recharge reservoir which connects
directly to the aquifer layer. The purpose of this study was to analyze the effectiveness of using sand columns in recharge
reservoirs as a buffer for sea water intrusion. This research is a numerical modeling study using SEAWAT program
simulation, which will produce data in the form of sea water intrusion. Parameters used are: the number of sand columns,
isochlor concentration, each parameter consists of 3 variables and the reservoir water level is 8 variables. The simulation
results obtained show the increasing number of sand columns and reservoir water height, the length of seawater intrusion
can be shortened even in the use of three sand columns, reservoir water level of 97 cm, a decrease of 2281.05%
compared to without using a sand column. On the contrary, the higher the long concentration of isochlor, the longer the
sea water intrusion.