Journal of Applied Geology And Geoscience

The IDENTIFICATION OF FLOOD VULNERABILITY PARAMETERS USING SCORING AND OVERLAY METHODS TO DETERMINE FLOOD ZONING IN NORTH SEMPAJA VILLAGE

2026-03-17T22:18:31+00:00

Flood disasters are one of the natural disasters that often occur in Indonesia, flood disasters are spread almost throughout Indonesian cities. The city of Samarinda is one of the big cities in Kalimantan with the frequency of floods almost every year, this is seen from the varied climate and the role of humans. The purpose of this research is to create a flood vulnerability zoning in the Samarinda city area, namely North Sempaja village, the research method used is through GIS (Geographic Information System) in the form of overlays and scoring based on flood vulnerability parameters such as river buffer, soil type, slope slope, altitude/topography, rainfall, land cover. To support the data in the research area, this study also analyzed the subsurface using the Active Digital Magnetotelluric (ADMT) method. Based on the results of the overlay and scorring analysis that has been carried out, it is divided into 3 classes of flood vulnerability, namely safe, vulnerable, and very vulnerable. Each class has different characteristics, the class is very prone to have characteristics, namely being at an altitude of 0 to 25 m, slope of flat slopes to sloping, the dominance of land cover in the form of settlements, rice fields, water bodies and zoning is very prone to being close to the river side, the vulnerable class is dominant at an altitude of 25 – 50 m, the slope of the slope varies flat to slightly steep, The dominance of land cover is in the form of bushes, rice fields and a few settlements, quite close to the river side, the last safe class is at an altitude of 50 to more than 100 m, the slope is slightly steep to very steep, the dominance of forests, bushes, and far from the river side. In addition to GIS analysis, the analysis of the ADMT method obtained a water-saturated layer in the form of clay and silt, groundwater, this analysis was then linked to the potential for flooding to subsurface geological factors in North Sempaja Village.

The Delineation of Groundwater Aquifer Systems Using Vertical Electrical Sounding (VES) in Sesela Village, West Lombok, Indonesia

2026-05-20T01:32:46+00:00

The expansion of residential areas in Sesela Village, West Lombok, has led to increased groundwater demand, while subsurface hydrogeological information remains limited. This study aims to delineate aquifer systems and characterize subsurface conditions to support preliminary groundwater assessment in the study area. The investigation was conducted using the resistivity method through Vertical Electrical Sounding (VES) with a Schlumberger configuration. Two VES points, spaced approximately 30 m apart, were acquired and interpreted using one-dimensional inversion to obtain resistivity values and layer thicknesses. The results from both VES points indicate a consistent subsurface structure consisting of seven layers. The interpreted lithology include topsoil, sand and gravel, volcanic breccia, lapilli tuff, and sandy tuff. Based on resistivity characteristics, three aquifer systems were identified. A shallow unconfined aquifer occurs at depths of 1.5–5 m, with resistivity values ranging from 10 to 25.4 Ωm, associated with sand and gravel deposits. An intermediate semi-confined aquifer is identified at depths of 9–26 m, with resistivity values between 23 and 29.3 Ωm, corresponding to lapilli tuff. A deeper confined aquifer is observed at depths of 57–116 m, with resistivity values ranging from 18.9 to 22.5 Ωm, interpreted as sandy tuff. These aquifer layers are separated by volcanic breccia layers characterized by relatively high resistivity values (131–671 Ωm), which act as aquitards. The similarity of resistivity patterns between the two VES points suggests relatively consistent vertical layering, although minor variations in depth are observed. The results provide preliminary information on aquifer distribution and subsurface conditions, which may serve as a basis for further hydrogeological investigation and groundwater resource assessment in Sesela Village.

GEOMORPHOLOGICAL AND COASTAL DYNAMICS STUDY USING RISK PARAMETERS IN KUTAI LAMA, ANGGANA SUB-DISTRICT, KUTAI KARTANEGARA REGENCY

2026-02-02T04:21:54+00:00

The coastal area of Kutai Lama in Anggana Sub-district is a dynamic region facing increasing risks due to active fluvial processes and intense anthropogenic pressures. Specific studies integrating local geomorphological characteristics into spatial disaster risk zonation in this area remain limited. This research aims to identify geomorphological characteristics, analyze the dynamics of riverbank changes, and develop a coastal disaster risk zonation map using weighted parameters. The study employs a quantitative descriptive method integrating Geographic Information System (GIS) analysis and the Analytical Hierarchy Process (AHP). Eight risk parameters classifed into Hazard, Vulnerability, and Capacity components were identified and weighted. Riverbank dynamics were analyzed using multi temporal Landsat 8 imagery for 2019 and 2024. The results indicate that the consistent AHP analysis (Consistency Ratio = 0.028) is dominated by three key parameters with equal weight: Riverbank Changes (32%), Population Density (21%), and Protective Infrastructure (13%). The final risk zonation map divides the area into five classes. The Medium Risk Zone dominates, covering 51.4% of the total area. However, High and Very High Risk Zones are identified covering a cumulative area of 1.214 km² (8.7%), significantly concentrated along the southern banks of the Meriam River (Bukuan Village), where active erosion intersects with dense settlements. This study provides a scientifically valid risk map to support stakeholders in formulating adaptive disaster mitigation strategies and spatial planning.

Petrogenetic Analysis of Ultramafic Peridotite Rocks Case Study: Tinanggea Area, Southeast Sulawesi Province

2026-01-08T12:59:11+00:00

Ultramafic rocks in the ofiolite complex of the Southeast Arm of Sulawesi have a fairly wide distribution in the Tinanggea Region. Administratively, the research area is located in Tinanggea District, Southeast Sulawesi Province. Geographically, it is located at coordinates and 4˚ 22' 15“to 4˚ 24' 14” South latitude (LS) dan 122˚10' 16.88“to 122˚12' 22” East Longitude (East). This study aims to determine the characteristics of ultramafic rocks, the type and origin of magma, and the environment that forms ultramafic rocks in the study area. This research was conducted on ten (10) ultramafic rock surface samples from the results of field mapping activities then carried out petrographic mineralogical analysis and geochemical analysis using XRF (X-Ray Flouresence). From the results of the data analysis, it was found that the types of ultramafic rocks in the study area consist of lherzolite and wehrlite. Based on major rock element data, ultramafic rocks in the Tinanggea area have ultramafic magma types with low SiO₂, with a thoellitic magma series that has high total MgO and FeO values. Ultramafic rocks in the study area were formed in the tectonic environment of the expansion of the ocean floor of the ocean ridge and floor and the ocean islands of the ocean island.

Design of a Moving Bed Biofilm Reactor (MBBR) to Address Problems of the Leachate Treatment Plant (LTP) at Banyuroto Landfill

2026-02-12T04:05:08+00:00

The Leachate Treatment Plant (LTP) at Banyuroto Landfill was constructed as an effort to control environmental pollution; however, its performance has not yet fully complied with the applicable effluent standards. This study aims to evaluate the performance of the existing LTP and to formulate an alternative development of a leachate treatment system based on a Moving Bed Biofilm Reactor (MBBR). The leachate flow rate was estimated using the Thornthwaite method based on climatic water balance, while leachate quality was evaluated by comparing laboratory analysis results with the effluent standards stipulated in Regulation of the Ministry of Environment and Forestry of the Republic of Indonesia No. 59 of 2016.

The evaluation results indicate that several key pollutant parameters, particularly organic matter and nitrogen compounds, still exceeded the effluent standards at the outlet of the LTP. Technical evaluation shows that limitations in capacity and process configuration of the existing treatment units hinder effective system optimization. Based on the analysis of leachate flow rate and pollutant loading, an MBBR-based treatment system is recommended as a replacement unit due to its higher process stability under fluctuating loads and better technical efficiency.

Keywords: leachate; leachate treatment plant; MBBR; effluent standard; Banyuroto landfill