Pemahaman tentang sistem hidrogeologi dan wilayah tangkapan air dari sebuah mata air sangatlah penting. Hal ini untuk membantu pengelolaan yang menjaga kelestariannya. Mataair Beton merupakan salah satu mataair yang memiliki peranan yang sangat penting di wilayah Ponjong, Kabupaten Gunungkidul. Suplai air dari mataair ini digunakan untuk memenuhi kebutuhan air bersih, irigasi persawahan dan perikanan. Penelitian ini bertujuan untuk mengetahui konektivitas dan karakterisasi lorong di sistem hidrogeologi Mataair Beton. Metode yang digunakan adalah tracer test dengan menggunakan fluorescent dyes. Hasil analisis menunjukkan bahwa Ponor Seropan memiliki konektivitas dengan Mataair Beton, dan memiliki karakteristik lorong berupa single conduit. Perkembangan lorong yang lanjut menunjukkan bahwa sistem hidrogeologi di lokasi kajian sangat dipengaruhi oleh imbuhan airtanah dari sistem alogenik yang berhulu di wilayah non-karst dan memiliki kerentanan terhadap pencemaran airtanah yang tinggi.Kata Kunci: Karst, Sungai Alogenik, Kawasan Karst Gunung Sewu, Uji Perunutan, Mataair BetonAn understanding of the hydrogeological system and catchment area of spring is very important. This is to help manage that maintains its sustainability. Beton Resurgence is one of the springs that have a very important role in the Ponjong area, Gunungkidul Regency. Water supply from the spring is used to supply clean water, irrigated rice fields, and fisheries. This study aims to determine the connectivity and characterization of Passage in the Beton hydrogeological system. The method used is a tracer test using fluorescent dyes. The results of the analysis of breaktrough curve indicate that Seropan Sinking Stream has connectivity with Beton resurgence, and has passage characteristics in the form of a single conduit. The further development of the passage shows that the hydrogeological system is strongly influenced by groundwater recharge originating from an allogenic system that originates in non-karst areas and has a high groundwater vulnerability to pollution. Keywords: Karst, Allogenic River, Gunungsewu Karst Area, Tracer Test, Beton Resurgence

Flow moving slowly (infiltration), and known as steady flow or baseflow is the only supplier of water in underground flows in the form of karst fields during the dry season. Certainly, the character contribution of this flow plays a major role in supporting the supplier of clean water. Understanding related to the character of baseflow in detail has a very high urgency to be studied. This Research aims to do a temporal analysis of baseflow contributions on epikarst water springs in Gunungsewu Karst Area, Indonesia. The research takes place in Guntur Springs that occupy the hydrogeological subsystem. Data used in this Research includes flow data from Guntur Springs for one year. The method used in this Research is automated base flow separation by digital filtering. Results of the analysis show that baseflow contribution in Guntur Springs are between 79.57% and 93.96%.

Allogenic rivers play a pivotal role in the development of the karst area. Their open system creates aggressive conditions that cause more intensive rock dissolution and, therefore, possibly form a primary underground river system in a hydrogeological regime. This study aimed to inventory allogenic rivers in the hydrogeological system of Gremeng Cave. This study also investigates Gremeng Cave typology based on underlying geological conditions by analyzing Indonesian topographic and geologic maps and high-resolution remote sensing imagery. In this study, a detailed geological survey was conducted to determine factors triggering the formation of allogenic rivers at the research site based on geological and geomorphological characteristics. The results showed at least five allogenic river subsystems uniting into one primary system. Allogenic from underlying beds exposed updip was the type of the allogenic rivers emerging exactly at the contact between tertiary volcanic rocks and limestones at the Gunungsewu karst area.

TPA Piyungan menampung sampah hingga 550 ton/hari, sehingga air lindi (leachate) yang dihasilkan akan lebih besar dan dapat berdampak pada airtanah. Tujuan dari penelitian ini adalah untuk mengidentifikasi pencemaran air lindi pada airtanah di sekitar TPA Piyungan, dan dilakukan dengan menggunakan metode Electrical Resistivity Tomography (ERT) konfigurasi Wenner Beta, flownet, dan uji sifat fisik-kimia air. Hasil dari penelitian adalah (1) aliran airtanah secara dominan bergerak ke arah Barat Laut dari TPA Piyungan yang merupakan kawasan padat permukiman; (2) hasil geolistrik metode ERT di Dusun Pleret menunjukkan adanya distribusi air lindi pada kedalaman 5-20 m dengan nilai resistivitas 1-3 Ώmeter, sementara kedalaman airtanahnya juga berada pada kedalaman 5-15 meter; (3) hasil pengukuran DHL, TDS, dan salinitas yang menunjukkan sebagian sumur memiliki nilai di atas baku mutu yang dipersyaratkan untuk air minum. Oleh karena itu, airtanah sekitar TPA Piyungan terutama bagian Barat Laut telah tercemar akibat air lindi.

The karst area in Panggang Subsystem, Gunungsewu has specific hydrogeological properties, including predominant epikarst springs with minimal discharge in dry seasons. Since this situation inevitably leads to drought, the installation of deep wells to extract water from deep aquifers is proposed as an alternative solution to water provision. This study determined the location of these wells using general geological and geomorphological surveys, followed by analyzing the results of geophysical measurements. The results showed potential aquifers in the sand layer of tertiary volcanic aquifers under the limestone formation that makes the karst region. Although three borewells were constructed at three different points, only two of them succeeded and are ready for use to meet the clean water needs of the population at the research site.