Claim Missing Document
Check
Articles

Found 2 Documents
Search

Identifying Dominant Structural Pattern of Semarang City Using Digital Elevation Model and Landsat 8-OLI Imagery Hidayatillah, Ahmad Syauqi; Nurcahyo, Tri Apri; Muliawan, Jody Bintara Pradiksa; Endarsih, Alfyah Edina
Journal of Geoscience, Engineering, Environment, and Technology Vol. 9 No. 1 (2024): JGEET Vol 09 No 01 : March (2024)
Publisher : UIR PRESS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25299/jgeet.2024.9.1.12706

Abstract

Semarang City is an area in the northern part of Java Island, administratively the Capital of Central Java Province. Because Semarang City is the provincial capital, Semarang City has a relatively dense population. Geologically, the city of Semarang is an area that consists of various types of lithology and is traversed by various regional geological structures. In this case, understanding the existence and distribution of geological structures in the city of Semarang is essential, considering that geological structures are one of the controllers for natural disasters such as landslides and earthquakes. This study analyzed the existence and distribution of geological structures in the city of Semarang based on the lineaments observed from digital elevation models and satellite imagery. This study aims to identify the dominant structural pattern in Semarang City, determine the relationship between fault fracture density (FFD) with regional geological structure and lithology, and determine the fault zone area in Semarang City based on FFD & lineament analysis. The method used in this analysis is to process DEM data and Landsat 8-OLI imagery, then interpret the lineaments in the form of rosset diagrams and the density in the form of FFD maps. The results of the rosset diagram analysis show that Semarang City has various structural lineament patterns, namely: North–South, Northeast–Southwest, and Northwest–Southeast, with the North–South pattern as the dominant pattern. Based on the results of the lineament density distribution on the FFD map, it is known that the area traversed by the Semarang regional geological structure has a high lineament density value which is interpreted that the area is a weak zone with high structural intensity. From this study, it can also be seen that there is no significant relationship between the type of lithology and the density value on the FFD map. The distribution of lineament density is not affected by the type of lithology, except in the northern and northeastern parts of Semarang city, which consist of alluvium. Based on these results, it can be interpreted that the fault zone area is associated with areas that have high-density values on the FFD map. Distribution of the fault zone area of Semarang City is spreading over the Banyumanik, Gunungpati, and Mijen Districts, which are relatively in the southern and central parts of Semarang City.
Analisis Perubahan Garis Pantai Menggunakan Digital Shoreline Analysis System untuk Mendukung Mitigasi Pesisir Kota Pekalongan, Jawa Tengah Endarsih, Alfyah Edina; Kurniasih, Anis; Khomarudin, M. Rokhis
Jurnal Teknologi Lingkungan Vol. 26 No. 1 (2025)
Publisher : BRIN Publishing (Penerbit BRIN)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/jtl.2025.3960

Abstract

ABSTRACT Shoreline changes in the form of abrasion or accretion often occur in coastal area due to dynamic natural processes. The northern coastal area of Pekalongan City is one the areas that has been facing significant abrasion, resulting in land loss along the coast. This abrasion process gradually damages the coastal embankments, allowing seawater to inundate inland areas so that tidal flood area expands and begins to encroach on residential areas. Therefore, research about shoreline changes is necessary as one of the mitigation approaches. This study aims to map shoreline changes in Pekalongan City from 2016 to 2022, analyze the values of these changes, and identify the causes in order to determine appropriate mitigation. Monitoring of these changes is conducted through remote sensing methods using Sentinel-2 images by applying threshold values to extract coastlines. The rate of shoreline change is subsequently calculated using Digital Shoreline Analysis System (DSAS) and validated with field conditions through direct observation surveys. The results showed that Pekalongan City experienced significant shoreline changes from 2016 to 2022. Maximum abrasion occurred in Bandengan with an average erosion of 79.5 m, while maximum accretion occurred in Panjang Wetan with an average addition of 3.88 m. Abrasion is the dominant process with a rate of change of 3.95 to 4.02 m/year. The main factor causing abrasion is the interaction between sedimentation with waves, ocean currents and wind. The construction of appropriate types of coastal protection can reduce wave energy and control ocean currents, protecting the coast from abrasion caused by sedimentation. ABSTRAK Perubahan garis pantai dalam bentuk abrasi maupun akresi sering terjadi di lingkungan pesisir yang disebabkan oleh adanya proses alam yang dinamis. Daerah pesisir utara Kota Pekalongan merupakan salah satu daerah yang mengalami abrasi signifikan yang berdampak pada hilangnya lahan di sekitar pantai. Proses abrasi tersebut perlahan menyebabkan kerusakan tanggul pantai yang membuat air laut masuk ke daratan sehingga area genangan banjir rob semakin meluas dan mulai merambah ke permukiman. Oleh sebab itu, penelitian tentang perubahan garis pantai penting dilakukan sebagai salah satu upaya mitigasi bencana abrasi. Penelitian ini bertujuan untuk memetakan perubahan garis pantai di Kota Pekalongan tahun 2016–2022, menganalisis nilai perubahan garis pantai, dan mengidentifikasi penyebab perubahan garis pantai sehingga dapat diketahui langkah mitigasi yang tepat. Pemantauan perubahan ini dilakukan dengan metode penginderaan jauh menggunakan citra Sentinel-2 yang dilakukan thresholding untuk mengekstrasi garis pantai. Laju perubahan garis pantai tersebut selanjutnya dihitung menggunakan Digital Shoreline Analysis System (DSAS) dan divalidasi dengan kondisi lapangan melalui survei pengamatan langsung. Hasil penelitian menunjukkan bahwa Kota Pekalongan mengalami perubahan garis pantai cukup signifikan pada tahun 2016–2022. Abrasi maksimum terjadi di Kelurahan Bandengan dengan pengikisan rata-rata 79,5 m, sementara akresi maksimum terjadi di Kelurahan Panjang Wetan dengan penambahan daratan rata-rata 3,88 m. Abrasi menjadi proses dominan dengan laju perubahan 3,95 hingga 4,02 m/tahun. Faktor utama penyebab terjadinya abrasi adalah interaksi antara sedimentasi dengan gelombang, arus laut, dan angin. Pembangunan jenis pelindung pantai yang sesuai dapat mengurangi energi gelombang dan mengendalikan arus laut sehingga dapat melindungi pantai dari abrasi yang disebabkan oleh sedimentasi.