IDENTIFIKASI ZONA PENGURANGAN AIR TANAH BERDASARKAN MODEL 3D GAYA BERAT MIKRO ANTAR WAKTU

Supriyadi -, WGA Kadir, Sarkowi -, R Herbet

Abstract


Penelitian ini dilatar belakangi oleh kenyataan bahwa di kota Semarang telah terjadi penurunan muka air tanah di beberapa lokasi. Penelitian menggunakan metoda gaya berat mikro antar waktu (time lapse selama kurun waktu Desember 2003 hingga Juni 2004 di daerah Semarang. Tujuan penelitian adalah untuk mengaplikasikan metoda gaya berat mikro dalam menentukan zona pengurangan air tanah dataran aluvial Semarang dan melakukan pemodelan 3D menggunakan program Grav3D untuk identifikasi zona pengur angan air tanah dataran aluvial Semarang. Akusisi metoda gaya berat dilakukan dengan menggunakan alat gravitimeter Lacoste & Romberg tipe G1158 dan G1118 yang dilengkapi dengan alliod 100 untuk mengukur gaya berat tiap stasiun dan gravitimeter Lacoste & Romberg tipe G508 untuk mengukur efek pasang surut terhadap gaya berat. Pemodelan 3D anomali gaya berat mikro time-lapse efek dinamika fluida mampu mengidentifikasi 9 zona pengurangan air tanah yakni sekitar masjid Ataqwa, PRPP, Tugu Muda , Simpang Lima, Jl. Majapahit, Genuk, Tanah Mas, Tanah Putih dan daerah sekitar kelurahan Sendangguwo.

The background of this research is that Semarang has experienced the ground water level degradation in some areas. The method used in this research was time lapse microgravity during December 2003 to June 2004. The purpose of the research is to apply the microgravity method in determining the reduction zone of groundwater and alluvial plains Semarang using a 3D modeling by usingGrav3D program to identify the reduction of groundwater zone of alluvial plains in Semarang. The acquisition method of gravity wass done by using a Lacoste & Romberg gravitimeter G1158 and G1118 type equipped with alliod 100 to measure the gravity of each station and Lacoste & Romberg gravitimeter G508 type to measure the tidal effect of the gravity. The 3D modeling microgravity anomaly time-lapse effects of fluid dynamics is able to identify 9 groundwater reduction zones which is about, Ataqwa mosque, PRPP, Tugu Muda, Simpang Lima, Jl. Majapahit, Genuk, Tanah Mas, Tanah Putih, and around Sendangguwo area.


Keywords


time lapse microgravity; groundwater

Full Text:

PDF

References


Akasaka C & Nakanishi S. 2000. An evaluation of the background noise for microgravity monitoring in the oguni field, Japan, Proceedings of 25th Stanford Geothermal Workshop, 24- 26 January 2000.

Branston MW & Style P. 2003. The application of time lapse microgravity for the investigation and monitoring of subsidence at northwich, chesire, J Eng Geol and Hydrogeol, 36 (3): 231 - 244.

Goodkind JM. 1986. Continous measurement of nontidal variations of gravity. J Geophysics Res. 91: 9125-9134.

Kadir WGA. 1999. Survey gaya berat 4 dimensi dan dinamika sumber bawah permukaan, Surabaya: Prosiding HAGI XXIV.

Lamber A & Beamont C. 1997. Nanovariations in gravity due to seasonal groundwater movement studies : implications for the gravitational detections of tectonics movements. J Geophysics Rese, 82: 297-306.

Lyness D. 1985. The gravimetric detection of mining subsidence. Geophysics Prospecting. 33: 567-576.

Reynolds JM. 1997. An introduction to applied and environmental geophysics, New York: John Wiley & Sons, Inc.

Sarkowi M. 2007. Gaya berat mikro antar waktu untuk analisa perubahan kedalaman muka air tanah (Studi Kasus Dataran Aluvial Semarang). Disertasi. ITB Bandung.


Refbacks

  • There are currently no refbacks.