Hydrogeochemistry of Epikarst Spring During Rainy Seasons in the Ponjong Hydrogeological Subsystem, Gunungsewu Karst Area, IndonesiaAulia Nisa Kurniatillah, Ahmad Cahyadi, Tjahyo Nugroho Adji, Indra Agus Riyanto, Fahry Adhi Satrio, Akhmad Singgih, Rasyiida Acintya and Wafiq Nur AzizahE3S Web Conf., 468 (2023) 08006DOI: https://doi.org/10.1051/e3sconf/202346808006