Groundwater utilization as a source of fresh water supply for various purposes in discharge area shows an ever to increasing trend, while land use of recharges also changes as development progresses. To meet its needs, many people rely on land-based exploration and exploitation. Groundwater is one of nature’s most valuable and inseparable resources for life on earth. Groundwater exploration requires appropriate and efficient techniques. One commonly used method is the electrical resistivity method since, it is efficient and economical to determine groundwater. Vertical Electrical Sounding (VES) Method measurement of rock resistivity from the surface to determine the subsurface rocked layer [1]. Geoelectric resistivity is one of the variables which is the physical properties of the rock layers below the surface. Rock resistivity data can be used to develop a model of subsurface and stratigraphic structures in terms of electrical properties. Geoelectric resistivity depends on lithology, air content, porosity, and pore ions concentration [2]. Geoelectric method is divided into two parts: Mapping resistivity method as a resistivity method that aims to study horizontal variations of horizontal layer resistivity types and Resistivity sounding method or, the drilling resistivity method that studies the variety of rock resistivity beneath the surface of the earth vertically. Data processing of geoelectric measurement results can be done by standard curve method, 2-Dimensional method (Schlumberger and Wenner), 3-Dimensional Method (Configuration of dipole-dipole, Lee Partition Configuration, Rectangle Line Source, 3 Point Gradient System). Therefore, ambiguity in interpretation can occur and become indispensable for calibrating the geoelectric measurement data with available borehole data to establish the resistivity range of various lithology units. Resistivity data can be used to identify and describe subsurface features such as the presence and type of aquifers, contaminated groundwater, and sediment size distribution [3, 4, 5].

Keberadaan air tanah perlu dikelola dengan baik secara kualitas dan kuantitasnya. Hal ini dilakukan agar sumber daya air dapat dimanfaatkan untuk memenuhi kebutuhan manusia baik secara langsung maupun tidak langsung. Penggunaan air tanah cenderung meningkat seiring dengan laju pertumbuhan penduduk, oleh karena itu perlu adanya perencanaan dan pemakaian air tanah yang bijak untuk melindungi sumber yang ada demi kelestarian sumberdaya air di Kecamatan Seputih Surabaya Kabupaten Lampung Tengah. Tujuan penelitian ini adalah untuk mendeteksi keberadaan akuifer air tanah berdasarkan jenis lapisan batuan dengan menggunakan alat geolistrik konfigurasi Schlumberger dan pemodelan dengan menggunakan software IP2Win di daerah Kecamatan Seputih Surabaya Kabupaten Lampung Tengah dengan jumlah titik pengukuran sebanyak 15 titik.Hasil penelitian menunjukkan bahwa jenis lapisan batuan yang terdapat pada daerah penelitian didominasi oleh lempung, pasir berlempung, lempung berpasir, pasir dan batuan kristalin. Dari hasil penelitian ini juga didapat bahwa akuifer air tanah rata-rata berada pada kedalaman 3,34 meter hingga 53,3 meter dari muka tanah. Jenis akuifer yang terdapat pada daerah penelitian adalah akuifer bebas dan akuifer tertekan.

Daerah Aliran Sungai adalah suatu wilayah yang berasal dari hujan ke danau atau ke laut secara alami. Untuk melaksanakan pengelolaan DAS di Kota Metro maka diperlukan penilaian kesehatan DAS. Mengetahui kualitas sungai berdasarkan indikator Makroinvertebrata yang berada di Kecamatan Metro Timur, Kecamatan Metro Barat. Menghitung kualitas sungai menggunakan formula DYTERasDAS. Menghitung kondisi di lapangan dengan indikator Makroinvertebrata formula DYTERasDAS. Nilai KRA 0,5 kualifikasi pemulihan nya sangat rendah. Koefisien aliran tahunan dan hasil perhitungan kualifikasi sangat tinggi, lahan kritis 47,346%. Penutup vegetasi di Kecamatan Metro Timur air 12,709%, area sawah 61,681%, perkebunan 4,770%, hutan 0,429%, pemukiman 20,354%, semak 0,158%. Kecamatan Metro Barat memiliki persentase bandan air 0,177%, area sawah 49,304%, 0,756 hutan, pemukiman 40,064% dan semak memiliki persentase sebesar 0,311%.Berdasarkan hasil penelitian yang telah dilaksanakan maka dapat diambil kesimpulan bahwa kesehatan Daerah Aliran Sungai pada wilayah Kecamatan Metro Timur dan Kecamatan Metro Barat disimpulkan bahwa air sungai kotor dan pencemaran agak berat.Rencana ke depannya perlu dilakukannya sosialisasi mengenai kesehatan air sungai secara berkala terutama mengenai Makroinvertebrata agar setidaknya sedikit mengetahui. Kepada para dosen khususnya yang berkopenten mengenai sumber daya air harus membuka wawasan lebih luas lagi kepada mahasiswa yang masih awam, agar berkembang kualitas menjadi lebih baik.

Over the past ten years, infrastructure development in Indonesia has undergone significant changes, particularly in terms of construction materials, one of which is concrete. Concrete is one of the most commonly used construction materials in the world, especially in building structures, bridges, roads, and other infrastructure. One of the main parameters that determine the quality and strength of concrete is compressive strength. Compressive strength describes the ability of concrete to withstand compressive forces and serves as a key indicator in determining concrete quality according to SNI classification. However, in practice, the compressive strength of concrete often does not meet the planned quality, mainly due to variations in constituent materials, mixing processes, casting execution, and suboptimal curing. In addition, external factors such as weather conditions, production equipment (batching plant), and technical errors in the field also affect the final quality of concrete. This study aims to develop a model for predicting concrete compressive strength using the Seasonal Autoregressive Integrated Moving Average (SARIMA) method with the assistance of SPSS software. The analysis was conducted using a factorial experimental design approach, with two factors including cylindrical sample shape as a fixed factor. A total of 30 samples were used. The compressive strength data were obtained from the Laboratory of Universitas Muhammadiyah Metro over a ten-year period (2015-2024), using samples that had been cured for 28 days.

Catchment area of aquatic system in Universitas Indonesia (UI) campus has a function as groundwater recharge for Depok area, which is the buffer zone of Jakarta. This catchment area has high level of imperviousness as a consequence of increasing population. The high imperviousness implicates in the degradation of the catchment area health. For that reason, the vulnerability assessment of UI catchment area is needed to arrange of restoration recommendation. This research applies Rapid Assessment Method which implements eco-hydrological concepts including aquatic and riparian condition as well as imperviousness of catchment area. Locations of the research are Kenanga and Agathis catchments area. The result of initial classification based imperviousness both catchment areas are categorised as Non-Supporting, where the imperviousness of Kenanga and Agathis is 31,0% and 77,18% respectivelly. Based on the assessment on aquatic and riparian condition as well as future land use, the final classification of both catchment areas is Restorable Non-Supporting catchment area.