Struktur Berpori Sebagai Upaya Penanggulangan Erosi di Pantai Utara Jawa (Studi Kasus Pantai Demak, Jawa Tengah)

https://doi.org/10.5614/jts.2021.28.3.9

Authors

  • Widyaningtias Widyaningtias Departement of Water Resources Engineering and Management, Faculty of Civil and Environmental Engineering, Institut Teknologi Bandung
  • Ingerawi Sekaring Bumi Departement of Civil Engineering, Faculty of Civil and Environmental Engineering, Institut Teknologi Bandung
  • Joko Nugroho Water Resources Engineering Reseacrh Group, Faculty of Civil and Enviromental Engineering, Institut Teknologi Bandung
  • M. Bagus Adityawan Center of Coastal and Marine Development, Institut Teknologi Bandung
  • Arno Adi Kuntoro Center of Coastal and Marine Development, Institut Teknologi Bandung

Abstract

Abstrak

Perubahan garis pantai merupakan salah satu masalah yang dihadapi masyarakat di kawasan pesisir utara Jawa, Indonesia. Hilangnya sabuk mangrove di kawasan pantai secara bertahap menyebabkan terjadinya erosi pantai. Untuk mengatasi masalah tersebut, konsep adaptif menggunakan Building with Nature (BwN) mulai dikembangkan di beberapa lokasi di pantai utara Jawa. Konsep ini diharapkan dapat menjadi solusi permasalahan erosi dengan memanfaatkan proses alam dan tetap memperhatikan kelangsungan ekosistem setempat, yaitu dengan pembangunan struktur berpori (permeable structure). Di kawasan pesisir Demak, pembangunan struktur berpori dimulai sejak 2013 di Desa Bogorame dan mampu menahan sedimen setinggi 45 cm dalam 1.5 tahun. Pemodelan akan menggunakan perangkat lunak Delft3D dengan meggabungkan antara model Delft3D-Flow dan Delft3D-Wave. Pemodelan dilakukan dengan menempatkan thin dam sebagai struktur berpori sesuai kondisi eksisting di lapangan. Simulasi akan dilakukan pada musim hujan dan kemarau, dengan memasukkan input gelombang signifikan pada kedua musim tersebut. Berdasarkan simulasi, dapat disimpulkan bahwa pada musim penghujan, struktur berpori menangkap lebih banyak sedimen dibandingkan pada musim kemarau. Pada beberapa lokasi, erosi terjadi saat musim penghujan, namun akan terisi kembali pada saat musim kemarau. Lebih lanjut lagi, konsep adaptif dari struktur berpori ini diharapkan dapat mempercepat restorasi pantai di kawasan pesisir Demak.

Kata-kata Kunci: DELFT3D, erosi pantai, struktur berpori.

Abstract

Shoreline degradation in North Java, Indonesia, becomes one of severe problem that have to be overcome by habitat along its coastal. The gradually vanishing of mangrove greenbelt indicates starting of coastal erosion. To solve that problem, the adaptive concept using Building with Nature (BwN) has been started to develop in some region in North Java Coastal area. This concept is expected as one of solution to restore coastal erosion by enhancing natural process. The application of permeable structures is proposed. The construction of permeable structures was started since 2013 in Bogorame area and has been trapped sediment up to 45 cm in 1.5 years. The simulation will be conducted using Delft3D by coupling between Delft3D-Flow and Delft3D-Wave. The model is simulated by using thin dams as permeable structures as in existing field condition, and will be modeled in wet and dry seasons. Based on simulations, it can be concluded that in wet season, permeable structures can trap more sediment compared with in dry season. In some location erosion occurs. However, it can be recharged by sediment transport during dry season. Furthermore, sustainability of this adaptive concept is expected to enhance the coastal restoration in Demak coastal area.

Keywords: DELFT3D, coastal erosion, permeable structure.

 

Published

2022-01-04