Electronic Theses and Dissertation

Secara administratif, lokasi penelitian terletak di daerah Kecamatan Tangan-Tangan, Kabupaten Aceh Barat Daya, Provinsi Aceh. Secara letak geografis berada pada koordinat 96º53’51.13” LU – 96º56’40.45” LU dan 3º37’21.84” BT – 340’9.13” BT dengan luasan blok pemetaan sekitar 25 Km². Pertumbuhan penduduk dan pembangunan yang pesat di Aceh menyebabkan kebutuhan akan air semakin tinggi, namun cadangan air yang dibutuhkan oleh masyarakat tidak stabil dari waktu ke waktu. Hal ini tentunya akan berdampak pada kualitas dan jumlah air di wilayah Aceh di masa yang akan datang, khususnya di Kecamatan Tangan-Tangan, Kabupaten Aceh Barat Daya. Penelitian mengenai sifat fisik dan kimia airtanah penting di lakukan didaerah penelitian untuk mengetahui kondisi hidrogeologi dan kualitas airtanah. Formasi Alluvium (Qh) menjadi target studi penelitian geokomia airtanah berdasarkan mayoritas masyarakat yang menggunakan airtanah sebagai air konsumsi. Penelitian ini bertujuan untuk mengetahui kondisi geologi daerah penelitiian dengan dilakukannya pemetaan geologi pada daerah penelitian dan mengetahui kualitas airtanah pada Endapan Alluvium (Qh). Selain itu, metode yang digunakan pemetaan geologi, analisis sifaf fisik dan kimia airtanah pada Endapan Alluvium (Qh) bertujuan untuk mengetahui kedalaman muka airtanah (MAT) pengujian sifat fisik pada airtanah dengan analisis berupa bau, warna, suhu, potential hydrogen (pH), total dissolved solids (TDS), daya hantar listrik (DHL), salinitas, dan sifat kimia berupa kandungan ion yang di analisis sulfat (SO₄²⁻), karbonat (CO₃²⁻), kalsium (Ca²⁺), bikarbonat (HCO₃⁻), magnesium (Mg²⁺), kalium (K⁺), natrium (Na⁺), klorida (Cl⁻) berdasarkan hasil uji laboratorium, dan petrografi. Hasil yang diperoleh dari penelitian yaitu kondisi geologi daerah penelitian dizonasikan menjadi 4 satuan, terdiri dari satuan batu tuff (Muvt), satuan batulanau (Muvt), satuan endapan kerikil-kerakal (Qpm), satuan endapan lempung (Qh). Kondisi geomorfologi daerah penelitian terdiri atas 4 bentang alam meliputi bentang alam struktural unit S1, bentang alam vulkanik unit V12, bentang alam denudasional unit D1 dan D5, bentang alam fluvial unit F1, F3 dan F4. Hasil dari analisis kualitas airtanah yaitu menghasilkan nilai kedalaman muka airtanah 2,08 meter, untuk analisis sifat fisik airtanah memiliki nilai suhu berkisaran 29⁰C-33⁰C, nilai potential hydrogen (pH) 7,4 dan 10,1 tergolong kedalam basa dan netral, nilai daya hantar listrik 105-7114 µmho/cm, nilai total dissolved solids 51-1145 ppm, dan salinitas 0,1-2 ppt. Berdasarkan hasil pengujian kimia airtanah di dapatkan hasil dari senyawa sulfat (SO₄²⁻) memiliki kadar 0,1, 6, 4, dan 10 mg/L, karbonat (CO₃²⁻) dengan kadar yang di peroleh 24 mg/L dari 4 sampel, kalsium (Ca²⁺) memiliki kadar 1,944, 38,4, 28,8, dan 19,2 mg/L, bikarbonat (HCO₃⁻) memiliki kadar 24,4, 1,076, 536,5, dan 366 mg.L, magnesium (Mg²⁺) memiliki kadar 1,944, 11,644, 4,86, dan 4,86 mg/L, kalium (K⁺) memiliki kadar 0,823, 9,046, 4,761, dan 1,772 mg/L, natrium (Na⁺) memiliki kadar 2,219,34,672, 4,016 dan 13,906, dan klorida (Cl⁻) memiliki kadar 2,85, 55,82, 2,73, dan 11,64, berdasarkan hasil pengujian kualitas airtanah berupa sifat fisik dan kimia airtanah dapat disimpulkan bahwa airtanah pada daerah penelitian tidak bagus secara 100 % namun masih dapat di kategorikan kedalam layak digunakan.

Kata Kunci : pemetaan geologi, hidrogeologi, kualitas airtanah, sifat fisik airtanah, sifat kimia airtanah

Administratively, the research site is located in Tangan-Tangan Sub-district, Southwest Aceh District, Aceh Province. Geographically located at coordinates 96º53'51.13” LU - 96º56'40.45“ LU and 3º37'21.84” E - 340'9.13” East with a mapping block area of approximately 25 Km². Rapid population growth and development in Aceh has led to higher demand for water, but the water reserves needed by the community are not stable over time. This will certainly have an impact on the quality and amount of water in the Aceh region in the future, especially in Tangan-Tangan District, Southwest Aceh Regency. Research on the physical and chemical properties of groundwater is important in the research area to determine the hydrogeological conditions and groundwater quality. The Alluvium Formation (Qh) is the target of the groundwater geocomia research study based on the majority of people who use groundwater as consumption water. This study aims to determine the geological conditions of the research area by conducting geological mapping in the research area and determine the quality of groundwater in the Alluvium Formation (Qh). In addition, the method used is geological mapping, analysis of physical and chemical properties of groundwater in Alluvium Deposits (Qh) aims to determine the depth of the groundwater table (MAT) testing physical properties of groundwater with analysis in the form of odor, color, temperature, potential hydrogen (pH), total dissolved solids (TDS), electrical conductivity (DHL), salinity, and chemical properties in the form of ion content analyzed sulfate (SO₄²-), carbonate (CO₃²-), calcium (Ca²⁺), bicarbonate (HCO₃-), magnesium (Mg²⁺), potassium (K⁺), sodium (Na⁺), chloride (Cl-) based on laboratory test results, and petrography. The results obtained from the research are that the geological conditions of the study area are zoned into 4 units, consisting of tuff rock units (Muvt), siltstone units (Muvt), gravel-crack deposits units (Qpm), clay deposits units (Qh). The geomorphological condition of the study area consists of 4 landforms including structural landscape unit S1, volcanic landscape unit V12, denudational landscape units D1 and D5, fluvial landscape units F1, F3 and F4. The results of the analysis of groundwater quality are to produce a groundwater depth value of 2.08 meters, for the analysis of the physical properties of groundwater has a temperature value ranging from 29⁰C-33⁰C, a potential hydrogen value (pH) of 7.4 and 10.1 classified into alkaline and neutral, an electrical conductivity value of 105-7114 µmho/cm, a total dissolved solids value of 51-1145 ppm, and a salinity of 0.1-2 ppt. Based on the results of chemical testing of groundwater, the results of sulfate compounds (SO₄²-) have levels of 0.1, 6, 4, and 10 mg/L, carbonate (CO₃²-) with levels obtained 24 mg/L from 4 samples, calcium (Ca²⁺) had levels of 1,944, 38.4, 28.8, and 19.2 mg/L, bicarbonate (HCO₃-) had levels of 24.4, 1,076, 536.5, and 366 mg. L, magnesium (Mg²⁺) had levels of 1.944, 11.644, 4.86, and 4.86 mg/L, potassium (K⁺) had levels of 0.823, 9.046, 4.761, and 1.772 mg/L, sodium (Na⁺) had levels of 2.219, 34.672, 4.016 and 13.906, and chloride (Cl-) had levels of 2.85, 55.82, 2.73, and 11.64, based on the results of testing the quality of groundwater in the form of physical and chemical properties of groundwater, it can be concluded that groundwater in the research area is not 100% good but can still be categorized into feasible use. Keywords: geological mapping, hydrogeology, groundwater quality, physical properties of groundwater, chemical properties of groundwater