Alternatif Desain Groin Pada Bangunan Pengaman Pantai Congot, Kulon Progo, Daerah Istimewa Yogyakarta

Widodo, Davis Adiatma (2026) Alternatif Desain Groin Pada Bangunan Pengaman Pantai Congot, Kulon Progo, Daerah Istimewa Yogyakarta. Diploma thesis, Institut Teknologi Sepuluh Nopember.

Text 2036221014-Undergraduate_Thesis.pdf - Accepted Version Restricted to Repository staff only Download (30MB) | Request a copy

Abstract

Pantai Congot, Kabupaten Kulon Progo, merupakan kawasan pesisir yang mengalami perubahan morfologi akibat interaksi gelombang, arus, pasang surut, serta suplai sedimen dari DAS Serang dan DAS Bogowonto. Meskipun telah dibangun bangunan pengaman pantai berupa jetty dan groin, abrasi masih terjadi pada beberapa segmen pantai sehingga diperlukan evaluasi terhadap konfigurasi bangunan yang ada. Penelitian ini bertujuan menganalisis karakteristik hidrologi DAS Serang dan DAS Bogowonto sebagai sumber suplai sedimen, karakteristik hidrodinamika dan transpor sedimen di Pantai Congot, serta mengevaluasi efektivitas beberapa alternatif desain groin melalui pemodelan numerik MIKE 21. Penelitian diawali dengan analisis hidrologi menggunakan metode F.J. Mock untuk memperoleh debit aliran dasar dan metode USLE untuk menghitung sedimen potensial sebagai data masukan pemodelan. Selanjutnya dilakukan pemodelan hidrodinamika, transpor sedimen, dan morfologi menggunakan MIKE 21/3 Coupled FM pada kondisi eksisting serta tiga alternatif orientasi groin, yaitu 45° ke arah timur, tegak lurus garis pantai, dan 45° ke arah barat. Evaluasi dilakukan melalui simulasi morfologi tahap awal dan simulasi morfologi jangka panjang menggunakan parameter bed level change. Hasil penelitian menunjukkan bahwa DAS Serang memiliki debit aliran dasar sebesar 1,36–8,84 m³/s dengan sedimen potensial sebesar 7,025 ton/ha/tahun, sedangkan DAS Bogowonto memiliki debit aliran dasar sebesar 3,17–13,99 m³/s dengan sedimen potensial sebesar 6,55 ton/ha/tahun. Pada kondisi eksisting masih dijumpai abrasi pada beberapa segmen pantai, salah satunya di Titik 7 dengan perubahan elevasi dasar sebesar −1,322 m. Variasi orientasi groin memengaruhi karakteristik hidrodinamika dan distribusi sedimen tersuspensi di kawasan pantai. Berdasarkan hasil simulasi morfologi, Alternatif 1 dengan orientasi groin 45° ke arah timur menghasilkan nilai bed level change positif pada seluruh titik pengamatan pada simulasi tahap awal serta menunjukkan peningkatan elevasi dasar pada enam dari delapan titik pengamatan pada simulasi jangka panjang dibandingkan kondisi eksisting. Oleh karena itu, Alternatif 1 direkomendasikan sebagai konfigurasi groin yang diusulkan dalam penelitian ini.
=======================================================================================================================================
Congot Beach, located in Kulon Progo Regency, Special Region of Yogyakarta, is a coastal area experiencing morphological changes due to the interaction of waves, currents, tides, and sediment supply from the Serang and Bogowonto Watersheds. Although coastal protection structures in the form of jetties and groins have been constructed, coastal erosion still occurs along several shoreline segments, indicating the need to evaluate the existing structural configuration. This study aims to analyze the hydrological characteristics of the Serang and Bogowonto Watersheds as sediment sources, investigate the hydrodynamic characteristics and sediment transport at Congot Beach, and evaluate the effectiveness of several alternative groin configurations using the MIKE 21 numerical model. The study began with hydrological analysis using the F.J. Mock method to estimate baseflow discharge and the Universal Soil Loss Equation (USLE) to determine potential sediment yield as input data for the numerical model. Hydrodynamic, sediment transport, and morphological simulations were then carried out using MIKE 21/3 Coupled FM under the existing condition and three alternative groin orientations, namely 45° eastward, perpendicular to the shoreline, and 45° westward. The alternatives were evaluated through both initial and long-term morphological simulations using the bed level change parameter. The results indicate that the Serang Watershed has a baseflow discharge ranging from 1.36 to 8.84 m³/s with a potential sediment yield of 7.025 ton/ha/year, while the Bogowonto Watershed has a baseflow discharge ranging from 3.17 to 13.99 m³/s with a potential sediment yield of 6.55 ton/ha/year. Under the existing condition, erosion still occurs along several coastal segments, including Observation Point 7, which experienced a bed level change of −1.322 m. Variations in groin orientation influence the hydrodynamic characteristics and the distribution of suspended sediment in the coastal area. Based on the morphological simulation results, Alternative 1, with a groin orientation of 45° eastward, produced positive bed level change values at all observation points during the initial simulation and showed an increase in bed elevation at six out of eight observation points during the long-term simulation compared with the existing condition. Therefore, Alternative 1 is recommended as the proposed groin configuration in this study.

Item Type:	Thesis (Diploma)
Uncontrolled Keywords:	coastal erosion, groin, sediment transport, MIKE 21/3 Coupled FM, Congot Beach, abrasi pantai, transpor sedimen, Pantai Congot
Subjects:	T Technology > TC Hydraulic engineering. Ocean engineering > TC203.5 Coastal engineering
Divisions:	Faculty of Vocational > 22301-Civil Infrastructure Engineering (D4)
Depositing User:	Davis Adiatma Widodo
Date Deposited:	04 Aug 2026 04:44
Last Modified:	04 Aug 2026 04:44
URI:	http://repository.its.ac.id/id/eprint/142526

Actions (login required)

View Item