ABSTRAK
Sistem akuifer karst memiliki sifat yang unik, dengan adanya perkembangan formasi batuan karena porositas sekunder. Tujuan penelitian ini adalah (1) Mengetahui pengaruh debit terhadap tinggi muka air, (2) Mengetahui fluktuasi aliran dalam bentuk hidrograf, (3) Mengetahui pengaruh curah hujan terhadap debit di Mataair Karst Kakap, (4) Mengimplementasikan hasil penelitian untuk pembelajaran geografi SMA kelas X.
Penelitian ini merupakan penelitian kuantitatif. Penelitian dilaksanakan dalam periode waktu 7 bulan, mulai Bulan April hingga Oktober 2014. Subjek penelitian adalah Mataair Karst Kakap di Kecamatan Giriwoyo Kabupaten Wonogiri. Sumber data berasal dari pengukuran debit dan pencatatan TMA serta curah hujan. Teknik pengumpulan data adalah dengan observasi langsung di lapangan dan dokumentasi atau arsip. Pengumpulan data menggunakan alat ukur pencatat hujan dan TMA otomatis serta metode pelampung untuk mengukur debit. Analisis data menggunakan teknik analisis deskriptif yang telah ditentukan oleh peneliti yang relevan sebelumnya.
Hasil dari penelitian ini menunjukkan bahwa (1) Pengaruh yang signifikan antara pengukuran debit dan pencatatan tinggi muka air dengan menggunakan logger TMA dengan nilai r2 = 0,768. (2) Grafik hidrograf aliran Mataair Karst Kakap menunjukkan respon yang cepat dengan rata-rata tp (time to peak) = 4 jam, sehingga Mataair Karst Kakap memiliki karakteristik aliran yang bersifat conduit. (3) Curah hujan di Mataair Karst tercatat begitu rendah, rata-rata curah hujan hanya 27,14 mm. Meskipun demikian, curah hujan mempengaruhi kenaikan debit aliran dengan respon yang cepat. (4) Hasil dari penelitian ini diimplementasikan pada pembelajaran geografi SMA kelas X.
Kata kunci : Mataair karst, curah hujan, tinggi muka air, debit, hidrograf
ABSTRACT
The karst aquiver system has unique characteristic in the presence of rock formation due to secondary porosity. The objectives of research were (1) to find out the relationship between water discharge and water surface height, (2) to find out the fluctuating flow in hydrograph form, (3) to find out how the effect of rainfall is on Kakap Karst spring, and (4) to implement the result of research to Geographical learning in the tenth grade of Senior High School.
This study was a quantitative research. This research was conducted for seven months, from April to October 2014. The subject of research was Kakap Karst spring in Giriwoyo Sub District of Wonogiri Regency. The data source derived from discharge measurement, TMA recording, and rainfall. Techniques of collecting data used were direct observation in the field and documentation or archive. The data was collected using automatic rain and TMA recorder and float method for collecting discharge. The data analysis was conducted using a descriptive analysis technique that has been determined by the previous relevant author.
The result of research showed as follows. (1) There was a significant relationship between discharge measurement and water surface height recording using logger TMA with r2 value = 0.768. (2) Hydrograph chart of Kakap Karst spring flow showed swift response with mean tp (time to peak) = 4 hours, so that Kakap Karst spring had conduit stream characteristic. (3) The rainfall in Karst spring was recorded as so low, with the mean value of 27.14 mm. Nevertheless, the rainfall affected the discharge increase with swift response. (4) The result of research to be implemented at Geographical learning in the tenth grade of Senior High School
Keywords: karst spring, rainfall, surface water height, discharge, hydrograph.