Karakteristik Hidrogeokimia dan Kualitas Air pada Mata Air Karst Selonjono Karst Gunungsewu Daerah Istimewa Yogyakarta

Abstract

Abstrak Mataair Selonjono memiliki keunikan secara geologi berupa mataair kontak antara dua formasi, sekaligus mataair patahan dan merupakan mataair epikarst. Kondisi tersebut menyebabkan mataair ini memiliki karakteristik hidrogeokimia dan kualitas air yang unik. Penelitian ini bertujuan untuk menganalisis variasi multi-temporal karakteristik hidrogeokimia dan kualitas air Mataair Selonjono. Sampel air diambil secara temporal mulai februari 2020 sampai dengan Januari 2021. Parameter yang diuji adalah suhu, Daya Hantar Listrik (DHL), Total Dissolved Solid (TDS), pH, Ca 2+ , Mg 2+ , Na + , dan K + , SO4 2-, Cl -, dan HCO3 -. Pengolahan data hidrogeokimia dilakukan dengan software Easy Quim v5.0 untuk menganalisis diagram piper segitiga dan diagram Schoeller, sedangkan kualitas air dibandingkan dengan baku mutu air. Mataair Selonjono termasuk dalam klasifikasi airtanah calsium enrichment, calsium/magnesium sulphate pollution, dan sulphate enrichment. Hasil diagram Schoeller menunjukkan pola ion kation dominan adalah Ca 2+ dan anion adalah SO4 2-. Hasil ploting pada scatter plot ion mayor komposisi Mataair Selonjono termasuk dalam klasifikasi silicat weathering atau cation exchange, pelarutan batuan karbonat yang dominan dan pelarutan dari material sulfat dan halit. Hasil analisis baku mutu air Mataair Selonjono secara temporal menunjukkan bahwa hampir semua sampel termasuk memenuhi baku mutu, hanya parameter Ca 2+ dan pH yang melebihi. Secara umum kualitas air Mataair Selonjono termasuk kategori sangat baik.

Anthropogenic activity effect on water quality of epikarst spring in the western part of Gunungsewu Karst Area, Java Island, Indonesia

“…However, the catchment area in the Guntur Spring is dominated by agricultural areas, which still allows for anthropogenic pollution from these two ions. Small sulfate and chloride values are also found in other karst sources in the Selonjono Spring (Cahyadi et al, 2022) River (Adji et al, 2023), Gremeng Resurgence (Cahyadi et al, 2020;, and Pindul Cave (Tastian et al, 2022). In the Jonggrangan and Gombong Karst Areas, the sulfate and chloride ion values are also comparably low (Pratama et al, 2021;Mahrizkhal et al, 2022).…”

“…This pattern is also found in Beton Resurgence and Gremeng Resurgence (Cahyadi et al, 2020;), Pindul Cave (Tastian et al, 2022, as well as in Jonggrangan and Gombong Karst Area (Pratama et al, 2021;Mahrizkhal et al, 2022). A different pattern was observed in the Selonjono Spring, with dominantly classified as A (Calsum Type), H (No dominant type), and I (Ca+Mg Type) (Cahyadi et al, 2022).…”

“…Several studies on the Gunungsewu Karst area are in the form of monitoring water quality, mainly focusing on water pollution from anthropogenic activities. However, the concentration of this monitoring is still limited to the large springs, which are located in the Ponjong Sub Hydrogeology and the Bribin-Baron system (Cahyadi et al, 2022;Adji et al, 2023), while monitoring in other parts of the karst area is still very rarely studied.…”

Hydrogeochemistry of Epikarst Spring During Rainy Seasons in the Ponjong Hydrogeological Subsystem, Gunungsewu Karst Area, Indonesia

“…The Gunungsewu Karst Area is one of the karst landscapes in Indonesia that has a substantial role in the provision of water resources. It is the most studied karst * Corresponding author: aulianisa01@mail.ugm.ac.id region in relation to hydrogeochemical characteristics of water originating in karst aquifers [9,10,11,12].…”

“…However, research on epikarst springs dominated by high diffuse flow is still rare [13]. Most studies in the area are centered on underground rivers and springs with large flow rates that are fed by allogenic rivers [9,10,11,12].…”