Asesmen Kerentanan Dan Risiko Pencemaran Air Tanah Menggunakan Modifikasi Model DRASTIC Studi Kasus Kota Batu Provinsi Jawa Timur

Hassan, Helmy (2022) Asesmen Kerentanan Dan Risiko Pencemaran Air Tanah Menggunakan Modifikasi Model DRASTIC Studi Kasus Kota Batu Provinsi Jawa Timur. Masters thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Air bersih merupakan aspek penting dalam menunjang kehidupan manusia, baik kebutuhan domestik maupun komersil. Salah satu sumber yang utama yang paling banyak dimanfaatkan adalah air tanah dangkal. Ketersediaan air baik secara kualitas maupun kuantitas penting untuk diperhatikan khususnya pada daerah imbuhan air tanah. Kota Batu merupakan daerah dengan karakteristik pegunungan yang merupakan daerah imbuhan air tanah CAT Brantas, dimana 99 % kebutuhan air bersih masyarakatnya berasal dari air tanah dangkal dan mataair. Alih fungsi lahan, akses sanitasi dan kegiatan pertanian memiliki risiko mencemari air tanah dangkal melalui sistem hidrologi yakni infiltrasi dan perkolasi air yang membawa polutan.
Berdasarkan mekanisme tersebut diperlukan kajian tingkat kerentanan risiko pencemaran air tanah dengan metode DRASTIC-a dan –b dengan perbedaan bobot dimana: (D: depth of water table, R: recharge capacity, A: aquifer material,S: soil type, T: topography, I: impact of the vadose zone , C: hydraulic conductivity) serta kombinasi dengan aspek tata guna lahan atau L sebagai aspek sumber risiko pencemarannya. Metode analisis berbasis pada pengolahan data GIS (geographic information system) menggunakan pengolahan data raster, krigging, interpolasi, skoring, prediksi perubahan tata guna lahan (mollusca) dan pembobotan dengan perangkat lunak ArcGIS 10.4. Uji sensitivitas parameter tunggal dilakukan untuk mengetahui aspek yang memiliki akurasi dan pengaruh tertinggi terhadap pemodelan DRASTIC. Sajian data dalam bentuk peta overlay polygon dan interpolasi dari titik sampel.
Hasil asesmen DRASTIC-a dan –b menunjukkan dominasi tingkat pencemaran sedang dengan persentase 94,29% dan 69,26%. Pada pemodelan dengan mempertimbangkan aspek tata guna DRASTIC-a+L lahan spesifik menunjukkan tren penurunan pada kawasan hutan menjadi risiko rendah seluas 7,41% namun meningkat pada daeah permukiman menjadi 25,81% daerah berisiko tinggi. Hasil dengan tren serupa terlihat pada DRASTIC-b. Skenario peningkatan akses sanitasi layak dan aman serta menghilangkan persentase sanitasi tidak layak memberikan implikasi positif yakni penurunan daerah berisiko tinggi menjadi 19,26%. Faktor paling mempengaruhi adalah jenis tanah, material akuifer dan topografi dengan nilai bobot efektif lebih besar dari teoritis. Hasil sampling dinas kesehatan Kota Batu juga menunjukkan keberadaan bakteri coli di air tanah dangkal.
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Clean water is an important aspect in supporting human life, both domestic and commercial needs. One of the main sources that are most widely used is shallow groundwater. The availability of water both in quality and quantity is important to be noticed, especially in groundwater recharge areas. Batu City is an area with mountainous characteristics which is a groundwater recharge area of the Brantas basins, where 99% of the community's clean water supply come from shallow groundwater and springs. Land conversion, access to sanitation, and agricultural activities may have the risk of contaminating shallow groundwater through the hydrological system, namely infiltration and percolation of water that carries pollutants.
Based on this mechanism, it is necessary to assess the vulnerability level of groundwater pollution risk using the DRASTIC-a and –b methods with different weights where: (D: depth of water table, R: recharge capacity, A: aquifer material, S: soil type, T: topography, I: impact of the vadose zone, C: hydraulic conductivity) and combination with land use or L aspects as sources of pollution risk. The analysis method is based on GIS data processing (geographic information system) using raster data processing, krigging, interpolation, scoring, prediction of land use change (mollusca) and weighting with ArcGIS 10.4 software. Single parameter sensitivity test was conducted to determine the aspect that has the highest accuracy and influence on DRASTIC modeling. Data presentation is in the form of polygon overlay maps and interpolation from sample points.
The results of the DRASTIC-a and –b assessments show the dominance of moderate pollution levels with a percentage of 94.29% and 69.26%, respectively. In the modeling by considering the specific land use aspects of DRASTIC-a+L, it shows a downward trend in forest areas to become low risk areas of 7.41% but increases in residential areas to 25.81% high risk areas. Results with a similar trend are seen in DRASTIC-b. The scenario of increasing access to proper and safe sanitation and eliminating the percentage of inadequate sanitation has a positive implication, namely a decrease in high-risk areas to 19.26%. The most influencing factors are soil type, aquifer material and topography with an effective weight value greater than theoretical. The results of the sampling of the Batu City Health Office also showed the presence of coli bacteria in shallow ground water.

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	Air Tanah, Kerentanan, Pencemaran, Groundwater, Vulnerability, Contamination
Subjects:	G Geography. Anthropology. Recreation > GE Environmental Sciences T Technology > TD Environmental technology. Sanitary engineering > TD194.6 Environmental impact analysis
Divisions:	Faculty of Civil, Planning, and Geo Engineering (CIVPLAN) > Environmental Engineering > 25101-(S2) Master Thesis
Depositing User:	Helmy Hassan
Date Deposited:	14 Feb 2022 02:30
Last Modified:	31 Oct 2022 03:35
URI:	http://repository.its.ac.id/id/eprint/93880

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