Penentuan Zona Recharge Cekungan Airtanah Subang dengan Menggunakan Pengujian Isotop Stabil

Villa Della Fonte Faradase, Yunus Ashari, Yuliadi Yuliadi

Abstract


Abstract. Subang District is one of the regions in Indonesia with a large enough groundwater potential (as evidenced by the number of springs found), and is used by the local community and industry as the main source of meeting water needs. However, not all industries and communities throughout the Subang area can benefit from the potential benefits of groundwater. This is due to restrictions on the use of groundwater in the Subang area, which is believed to be a Conservation Zone. This zone is determined because the area is included in the recharge area.The purpose of this research is to determine the equation of the local meteoric line (LMWL - Local Meteoric Water Line) as a standard for rain infiltration in CAT, to determine the groundwater group based on its isotope composition, and to determine the recharge zone based on its isotope composition. The method used in determining the recharge zone can be done by using environmental isotopes in the field of hydrogeology, one of which is through the analysis of the stable isotope composition of Deuterium and Oxygen-18, whose utilization can determine the recharge zone and also the origin of groundwater.In this study, the results of stable isotope testing in the form of an LMWL (local meteorical water line) of δ2H (‰) = 20,6361 + 8,4008 δ18O still similar to Global Meteoric Water Line (GMWL) as big as δ2H (‰) = 10 + 8 δ18O. and obtained 2 groups of groundwater, the result of which the intersection of rainwater and each group of groundwater is enriched with the composition of isotope values. δ2H (‰) dan δ18O (‰) each for groundwater groups A and B of (δ2H (‰) = - 42,7168 and δ18O (‰) = - 7,5413) and (δ2H (‰) = - 45,5312 and δ18O (‰) = - 7,8763). As for the recharge zone in the Subang Groundwater Basin, it is at an elevation of 925 to 970 masl.From this research it can be concluded that the recharge area in the subang area is sourced at an elevation of 925 to 970 masl which is located in the southern direction of Subang, thus this area needs to be given special attention, especially in the protection of the area in terms of land use so that water sustainability can be maintained until this point. output or discharge zone.

Keywords : Groundwater Basin, Recharge, Stable Isotop Deuterium and Oxygen-18

Abstrak. Kabupaten Subang merupakan salah satu wilayah di Indonesia dengan potensi airtanah yang cukup besar (dibuktikan dengan banyaknya mata air yang dijumpai), dan dijadikan oleh masyarakat maupun industri sekitar sebagai sumber utama pemenuhan kebutuhan air. Namun, tidak semua industri maupun masyarakat seluruh kawasan Subang dapat merasakan manfaat potensi airtanah tersebut. Hal ini dikarenakan adanya pembatasan akan pemanfaatan airtanah di Kawasan Subang yang diyakini sebagai Zona Konservasi. Zona ini ditetapkan karena kawasan tersebut termasuk ke dalam kawasan recharge (resapan). Tujuan dilakukannya penelitian ini adalah untuk mengetahui persamaan garis meteorik lokal (LMWL – Local Meteoric Water Line) sebagai standard resapan hujan di dalam CAT, mengetahui kelompok airtanah berdasarkan komposisi isotopnya, dan menentukan zona recharge berdasarkan komposisi isotopnya. Adapun metode yang digunakan dalam menentukan zona recharge dapat dilakukan dengan menggunakan isotop lingkungan di bidang hirdrogeologi, salah satunya melalui analisis komposisi isotop stabil Deuterium dan Oksigen-18 yang pemanfaatannya dapat menentukan zona recharge dan juga asal-usul airtanah. Dalam penelitian ini didapatkan hasil pengujian isotop stabil berupa garis LMWL (local meteorical water line)sebesar δ2H (‰) = 20,6361 + 8,4008 δ18O masih serupa dengan Global Meteoric Water Line (GMWL) sebesar δ2H (‰) = 10 + 8 δ18O. dan didapatkan 2 kelompok air tanah yang hasil perpotongan antara air hujan dengan masing-masing kelompok air tanah mengalami pengayaan dengan komposisi nilai isotop δ2H (‰) dan δ18O (‰) masing masing untuk kelompok air tanah A dan B sebesar (δ2H (‰) = - 42,7168 dan δ18O (‰) = - 7,5413) dan (δ2H (‰) = - 45,5312 dan δ18O (‰) = - 7,8763). Adapun untuk zona recharge di Cekungan Air Tanah Subang berada pada elevasi 925 hingga 970 mdpl. Dari penelitian ini dapat disimpulkan bahwa Kawasan recharge di daerah Subang bersumber pada elevasi 925 hingga 970 mdpl yang terletak di selatan Subang, dengan demikian pada Kawasan ini perlu diberikan perhatian khusus terutama dalam perlindungan Kawasan dalam hal tata guna lahan agar kelestarian air dapat terjaga sampai dititik keluaran atau zona discharge.

Kata Kunci : Cekungan Airtanah (CAT), Recharge, Isotop Stabil Deuterium dan Oksigen-18


Keywords


Cekungan Airtanah (CAT), Recharge, Isotop Stabil Deuterium dan Oksigen-18

Full Text:

PDF

References


Ashari, Yunus., 2015. “Kontrol Sesar Terhadap Sistem Akuifer dan Sistem Aliran Airtanah,dan Akibat Keberadaannya Terhadap Hidrokimia Cekungan Airtanah Bandung Bagian Timurâ€, Universitas Padjajaran, Bandung.

Ashari, Yunus., Pulungan, L., Wijaksana, I.K., Isniarno, N.F and Mildan, D.2019 “Groundwater Study in Subang Industrial Park and Its Recharge Area as a Suggestion for Establishing Recharge and Discharge Zones of Subang Groundwater Basinâ€. Proceeding Science and Technology Research Symposium – Unisba Bandung.

Ashari, Yunus., 2020. “Kajian Lanjutan Delineasi Zona Resapan CAT Subang dan CAT Ciater Provinsi Jawa Baratâ€, Dinas ESDM Provinsi Jawa Barat. (Dalam proses akan dipublikasi).

Back, W., and Freeze, R.A., 1983. “Chemical Hydrogeology†, Editors Bench-mark Papers in Geology /73, Hutchinson Ross Publishing Company, Stroudsburg, Pennsilvania, 415 p.

Barbieri, Maurizio. 2019. “Isotopes in Hydrology and Hydrogeologyâ€.Departement of Earth Sciences, Sapienza University of Rome, Piazzale Aldo Moro5, 00185 Roma, Italy.

Bemmelen, R.W., van, 1949; “The Geology of Indonesia, The Hague Martinus Nijhoffâ€, vol. 1A, 732 h.

Bleackney, W., Gould, A. J., 1993. “ The Relative abundance of Hydrogen Isotopesâ€, Phys. Rev. 44,265.

Clayton, R.N., Friedman, I., Graft, D.L., Mayeda T.K., Meents, W.F., and Shimp, N.F., 1966. “The Origin of Saline Formation Water, 1. Isotopic Compositionâ€, Journal Geophys. Res.,71(16), American Geophysical Union, 3869 - 3882 pp.

Clustius, K., Dickel, G., Becker, E. 1943, “Pure Representation of Heavy Oxygen - isotopes 1802 and Nitrogen 14N15Nâ€, Natural Sciences 31,210.

D.K. Todd. Wiley., 1980. “Groundwater Hydrology (2nd edn)â€, New York

Dansgaard, W., 1964. “Stable Isotopes in Precipitationâ€, Tellus, 16(4), Swedish Geophysical Society, 436-468 pp.

Darsono, 2016. “Identifikasi Akuifer Dangkal dan Akuifer Dalam dengan Metode Geolistrik†(studi kasus : kecamatan Masaran, Sragen), Indonesian Journal of Applied Physics. 40-49.

Dostrowsky, I., Raviv, A. 1958, “Separation of the heavy isotopes of oxygen by distillationâ€, Isotope Separation (Proc Int. Symp. Amsterdam, 1957) (KISTEMAKER, J., BIGELEISEN, J., NIER, A.O.C., Eds), p.336, North Holland, Amsterdam

Drever, J.I., 1988; “The Geochemistry of Natural Watersâ€; Prentice-Hall 2nd, Englewood Cliffs, 437 p.

Freeze, R.A., & Cherry, J.A., 1979. “Groundwaterâ€, Prentice Hall, Englewood Cliffs, New Jersey, 604 p.

Friedman, I.,1953.Deuterium Content of Natural Waters and Other Substances, Geochim. Cosmochim. Acta, 4(1-2), 89 - 103 pp.

Fritz, P. , Fontes, J. Ch. 1980. “Environmental Isotopes In Groundwater Hydrology†Handbook of Environmental Isotope. Vol 1. Netherlands.

Gat JR. 1996. “Oxygen and Hydrogen Isotopes In The Hydrologic Cycle.†Department of Environmental Sciences and Energy Research, WeizmannInstitute of Science, 76100 Rehovot, Israel.

Giauque, W.F., Johnston, H.L. 1929, “An isotope of oxygen, mass 18â€, J. Am. Chem. Soc. 51,1436

Gonfiantini, R., Araguas, L.A. 1988. Isotop lingkungan dalam studi tentang intrusi laut, TIAC' 88, Teknologi Intrusi Akuifer Pesisir, IAEA, Wina.

Hagemann, R., Hief, G., Roth, E. 1970. “Absolute Isotopic Scale for Deuterium Analysis of Natural Waters.†Absolute D/H ratio for SMOW, Tellus 22, 712.

Hendrasto, fajar., dan Sunarwan, B., 2013. “Pemanfaatan Isotop Lingkungan Di Daerah Cekungan Airtanah Bandung†Jurnal TEkonologi Vol 1.

International Atomic Energy Agency (IAEA), 1983. “Guidebook on Nuclear Techniques in Hydrogeologyâ€, Technical Reports Series No. 91, Vienna 439 p.

KarolytÄ—, RÅ«ta., Serno, Sascha., Johnson, Gareth., Stuart M.V. Gilfillan. 2017. “The Influence of Oxygen Isotope Exchange Between CO2 and H2O in Natural CO2-rich Spring Waters: Implications for Geothermometryâ€. 1School of GeoSciences, University of Edinburgh, Grant Institute, James Hutton Road, 5 Edinburgh, EH9 3FE, U.K.

Koesoemadinata, R.P dan Hartono, D. 1981. “Stratigrafi dan Sedimentasi Daerah Bandungâ€, Proc. PIT X IAGI, Bandung.

Krauskopf, K.B., 1979. “Introduction to Geochemistryâ€, International Student Edition, McGraw-Hill Kogakusha, Ltd., 617 p.

LLoyd, J.W.,and Heathcote, J.A., 1985. “Natural Inorganic Hydrochemistry in Relation to Groundwater, An Introductionâ€, Clarendon Press - Oxford, 296 p.

Martodjojo, S., 1984; Evolusi Cekungan Bogor Jawa Barat, Disertasi Doktor Fakultas Pascasarjana Institut Teknologi Bandung, 396 h.

Sunarwan, Bambang., Irawan, Erwin. I., Puradimaja, Deny. J., Notosiswoyo, S. 2013., Perubahan Karakter Isotop 2H dan 18O Air Tanah Pada Akuifer Dangkal Di CAT Bandung-Soreang.

Stumm W . & Morgan, J.J., 1981. “Aquatic Chemistry, an Introduction Emphasing Chemical Equilibriain Natural Watersâ€; 2nd Ed., John Willey & Son, NY-Chichester-Brisbane-Toronto-Singapore.

Zuidam, R.A. Van., 1983 : “Guide to Geomorphologic Aerial Photographic Interpretation and Mappingâ€, ITC, Enschede The Netherlans, 325 hal.

Prahasta Guntur Indra, Yuliadi, Moralista Elfida. (2021). Redesign Geometri Lereng Penambangan Batugamping Kuari C di PT X Kecamatan Palimanan Kabupaten Cirebon Provinsi Jawa Barat. Jurnal Riset Teknik Pertambangan, 1(1), 30-38.




DOI: http://dx.doi.org/10.29313/pertambangan.v0i0.30657

Flag Counter