Hasil Pencarian  ::  Simpan CSV :: Kembali

"Hujan ekstrem melanda Kota Jakarta Timur pada tanggan 19 Februari 2021 dan menyebabkan banjir di sejumlah kelurahan. Penelitian dilakukan di bagian tengah Kali Sunter, Jakarta Timur yang mengalir melalui tiga kelurahan yaitu Cipinang Melayu, Cipinang Muara, dan Pondok Bambu. Tujuan penelitian adalah memodelkan sebaran wilayah bahaya banjir dan menganalisis karakteristik wilayah terdampak banjir berdasarkan penggunaan lahan serta topografi. Pembuatan peta genangan dan bahaya banjir dilakukan dengan: perhitungan debit banjir dengan metode SCS-CN, pemodelan genangan banjir dengan HEC-RAS, serta analisis karakteristik wilayah genangan banjir. Kombinasi tersebut efektif untuk memodelkan genangan saat kejadian curah hujan yang ekstrem. Berdasarkan penelitian, sebaran wilayah bahaya banjir yang tertinggi adalah yang berada di RW 004 Kelurahan Cipinang Melayu. Cipinang Melayu pun merupakan kelurahan dengan genangan terluas dengan hunian ukuran kecil dan sedang sebagai jenis penggunaan lahan paling terdampak. Karakteristik wilayah terdampak yaitu terdapat lahan hijau dan kosong yang mengurangi potensi air menggenangi bangunan atau penggunaan lahan lainnya. Bangunan yang berada di perumahan dengan tingkat bahaya rendah cenderung lebih teratur dan relatif berukuran sedang hingga besar. Sedangkan jenis hunian yang ada di Kelurahan Cipinang Melayu dengan tingkat bahaya tinggi cenderung rapat dan berukuran kecil hingga sedang, namun mayoritas memiliki dua lantai sebagai bentuk adaptasi banjir.

---

Extreme rainfall in East Jakarta on February 19, 2021 caused flooding in a number of subdistricts. The research was conducted in the central part of Kali Sunter, which flows through three subdistricts, namely Cipinang Melayu, Cipinang Muara, and Pondok Bambu. The purpose of the study was to do flood hazard modeling and analyze the characteristics of flood-affected areas based on land use and topography. Inundation and flood hazard maps is done by: calculating the flood discharge using the SCS-CN method, flood inundation modelling using HEC-RAS, and analyzing the characteristics of the inundated area. This combination is effective for rapid modeling during extreme rainfall events. Based on the research, the distribution of the highest flood hazard area is in RW 004 Cipinang Melayu, with the widest inundation affecting small and medium-sized houses. The characteristics of the affected area are that there is green and empty land which reduces the potential for water to inundate buildings or other land uses. Buildings located in low-hazard housing areas tend to be more organized and relatively medium to large in size. While the types of housing in the Cipinang Melayu with a high level of danger tend to be dense and small to medium in size, but the majority have two floors as a form of flood adaptation. "

"Rainfall is the primary input into rainfall-runoff modeling. Previous work indicates that the accurate representation of rainfall in time and space is important due to its influence on the hydrological response. The objective of this study is to evaluate the relevance of theoretical indices of spatial rainfall variability and the theoretical criteria of the hydrological response proposed by Emmanuel et al. (2015) in a real case study. The distributed model CINECAR has been chosen to accommodate the spatial discretization of hydrological data. The production function of the model adopts the Soil Conservation Service-Curve Number method, while the transfer function is based on a kinematic wave model. The simulations used weather radar data and also their average over the watershed, with a data resolution of 1×1 km2. They were conducted on the basis of 13 watersheds in the Gard region and four events in 2008 for each watershed. The difference between the distributed and averaged hydrographs obtained from the CINECAR model were calculated using two criteria, namely the difference in peak discharge (LQ) and the difference in peak time (TQ). The values of LQ and TQ represent the influence of spatial rainfall variability on the hydrological response. The spatially distributed rainfall was analyzed based on the values of its maximum Horizontal and Vertical Gab (HG and VG) to watershed centroid acting as indices, as proposed by Emmanuel. The analysis of the influence of spatial rainfall variability on the watershed response was conducted by quantification of the averaged and distributed hydrographs using the proposed indices and criteria. The results show that value of LQ rises by more than 50% for some events, and that TQ shows different times to peak between the average and distributed hydrographs. The values of the HG and VG indices accurately describe the rainfall distribution in the watershed. Therefore, these criteria and indices are effective in quantifying the influence of spatial rainfall variability on the hydrological modeling in particular events which are affected by rainfall distribution."