Bentang lahan karst Gunungsewu tersusun oleh batuan gamping (CaCO3) yang memiliki sifat mudah larut oleh air CO2. Air permukaan yang terpolusi langsung menuju sungai bawah tanah tanpa adanya filtrasi sehingga sungai di wilayah karst Gunungsewu rentan terhadap pencemaran. Mata air Goa Gremeng merupakan salah satu mata air karst Gunungsewu yang perlu dilakukan pengelolaan. Mata air Goa Gremeng digunakan masyarakat untuk pemenuhan kebutuhan air domestik. Upaya pengelolaan mata air memerlukan pemahaman karakteristik sensitivitas area tangkapan terhadap hujan. Tujuan penelitian ini adalah untuk mengetahui sensitivitas area tangkapan mata air karst Goa Gremeng.
Jenis penelitian yaitu deskriptif kuantitatif dengan metode survey. Metode pengambilan sampel yang digunakan adalah Purposive Sampling. Data yang diambil yaitu data curah hujan dan tujuh parameter kualitas air (Kekeruhan, Total Dissolve Oxygen (TDS), temperature, pH, Dissolve Oxygen (DO), Kesadahan CaCO3 dan Nitrat). Teknik analisis data yang digunakan yaitu korelasi tunggal dan deskriptif. Parameter kualitas air hasil pengukuran akan dikorelasikan dengan pola curah hujan di area tangkapannya.
Hasil penelitian menunjukkan 1) Konsentrasi parameter kualitas mata air Goa Gremeng yaitu Kekeruhan ,TDS dan Kesadahan CaCO3. 2) Hasil korelasi parameter kualitas air terhadap curah hujan yaitu a) Kekeruhan 0,757 = korelasi kuat b) TDS -0,846 = korelasi sangat kuat c) Temperatur -0,651 = korelasi kuat d) DO -0,257 = korelasi lemah e) pH 0,422 = Korelasi sedang f) Kesadahan CaCO3 -0,565 = korelasi sedang g) Nitrat -0,732 = korelasi kuat. 3) Sumber bahaya pencemar yang berpotensi terhadap pencemaran mata air Goa Gremeng yaitu Erosi tanah batuan, limbah industri, pertanian dan kotoran manusia.
Kata kunci : Karst, Sensitivitas, Mata Air Goa Gremeng, Kualitas Air, Curah Hujan
The landscape of Gunungsewu karst land is composed of limestone (CaCO3) which has a soluble nature by CO2 water. Polluted surface water flows directly to the underground river without filtration made the rivers in the Gunungsewu karst region are susceptible to pollution. The Gremeng Cave spring is one of the Gunungsewu karst springs that needs to be managed. The spring of Gremeng Cave is used by peoples to fulfill domestic water needs. Springs management efforts require understanding the sensitivity of the catchment area to rain. The purpose of this study was to determine the sensitivity of the karst spring catchment area of Gremeng Cave.
The type of research is quantitative descriptive with survey method. The sampling method used is Purposive Sampling. The data taken is rainfall data and seven parameters of water quality (Turbidity, Total Dissolve Oxygen (TDS), temperature, pH, Dissolve Oxygen (DO), Hardness of CaCO3 and Nitrate). The data analysis technique used is single and descriptive correlation. Water quality parameters measured will be correlated with rainfall patterns in the catchment area.
The results showed 1) three concentrations of Goa Gremeng karst spring quality parameters namely Turbidity, TDS and Hardness of CaCO3. 2) Correlation calculation results of water quality parameters on rainfall are a) Turbidity 0.757 = strong correlation b) TDS -0.846 = very strong correlation c) Temperature -0.6651 = strong correlation d) DO -0.257 = weak correlation e) pH 0.422 = Medium correlation f) Hardness of CaCO3 -0.565 = moderate correlation g) Nitrate -0,732 = strong correlation. 3) Potential sources of pollutant potential to contaminate Goa Gremeng springs, namely soil rock erosion, industrial waste, agricultural and human waste.
Keywords: Karst, Sensitivity, Gremeng Cave spring, Water Quality, Rainfall