Judul: Review of the Effectiveness of  Retention Ponds as Flood Control in the Housing Area of Summarecon Bogor
Abstrak: Salah satu upaya yang dapat dilakukan untuk pengendalian banjir adalah dengan pembuatan kolam retensi. Kolam retensi berfungsi untuk memotong puncak banjir yang terjadi dalam badan air / sungai dan sebagai pariwisata air. Penelitian ini dimaksudkan untuk mengkaji ulang efektivitas kolam retensi yang meliputi efektivitas tangkapan hujan dan efektivitas tampungan. Debit banjir rencana kolam retensi hasil Hidrograf Nakayasu distribusi 6 jam dengan periode ulang 25 tahun sebesar 97,67 m3 /detik. Elevasi muka air normal berada di +372,50 mdpl dengan luas genangan 8666,76 m2 dan volume tampungan 37138,85 m3 . Elevasi muka air banjir berada di +373,92 mdpl dengan luas genangan 9926,32 m2 dan volume tampungan 49631,60 m3 . Posisi kawasan kolam retensi Summarecon Bogor berada pada titik pengaliran catchment area, maka dapat diperkirakan bahwa efektivitas tangkapan kolam retensi sebesar 100%. Nilai active storage adalah sebesar 26,66%, namun tidak efektif untuk penampungan karena tidak dilengkapi bangunan pengatur outlet. Kedalaman aliran kritis pada bangunan spillway sebesar 1,42 m. Sebagai upaya penyempurnaan bangunan kolam retensi terbangun, diperlukan kajian lebih lanjut tentang saluran inlet dan bangunan pengatur outlet.
Keyword: capacity, design discharge, effectiveness, retention pond

Judul: Review of Runoff in the Context of  Construction of the Baranangsiang Retention Pool in Bogor City
Abstrak: Beberapa faktor penyebab banjir, seperti berkurangnya daerah tangkapan air akibat peralihan fungsi lahan dan curah hujan tinggi menjadi dasar dalam perencanaan kolam retensi. Pengkajian ulang limpasan untuk pembangunan kolam retensi Baranangsiang dilakukan seiring dengan perubahan landuse dan curah hujan. Penelitian ini bertujuan menganalisis volume limpasan serta merekomendasikan kapasitas dan dimensi kolam retensi yang sesuai dengan volume limpasan. Digunakan metode Hidrograf Satuan Sintetik Nakayasu dan diperoleh debit puncak runoff dengan kala ulang 5 tahun sebesar 7,26 m3/detik dan volume kumulatif limpasan sebesar 69.187,13 m3 sedangkan kapasitas tamping kolam hasil kaji awal hanya 38.573,48 m3. Efektivitas tampungan kolam retensi hasil kaji awal terhadap volume limpasan diperoleh sebesar 55,75 % sehingga perlu dilakukan perubahan dimensi tampungan kolam dari 9.643,37 m3 menjadi 11.531,19 m3 untuk luas kolam dan kedalaman kolam retensi diubah dari 4 m menjadi 6 m sehingga efektivitas kolam retensi menjadi 100%. Dinding kolam retensi menggunakan tipe kantilever di inlet kolam. Beda tinggi antara inlet dan outlet sekitar 7 m sehingga pada titik keluar (outlet) dibangun konstruksi tubuh bendungan dengan tinggi 7 m dan lebar bentang pondasi 9,61 m., Several factors that cause flooding, such as reduced water catchment areas due to landuse changes and high rainfall, are the basis for planning retention ponds. The review of runoff for the construction of the Baranangsiang retention pond was carried out in line with changes in landuse and rainfall. This research aims to analyze runoff volume and recommend the capacity and dimensions of retention ponds that are appropriate to the runoff volume. The Nakayasu Synthetic Unit Hydrograph method was used and the peak runoff discharge with a return period of 5 years was 7.26 m3 /second and the cumulative runoff volume was 69,187.13 m3 , while the tamping capacity of the pond from the initial study was only 38,573.48 m3 . The effectiveness of the retention pond storage from the initial study on runoff volume was found to be 55.75% so it was necessary to change the dimensions of the retention pond from 9,643.37 m3 to 11,531.19 m3 for the area of the pond and the depth of the retention pond to be changed from 4 m to 6 m so that the effectiveness of the pond retention to 100%. The retention pool wall uses a cantilever type at the pool inlet. The height difference between the inlet and outlet is around 7 m so that at the outlet point a dam body construction is built with a height of 7 m and a foundation span width of 9.61 m.
Keyword: discharge, runoff volume, retention pond, effectiveness, dimensions

Judul: Phylogenetic analysis of subgenus Dieramalpinia (Alpinia carolinensis clade) - Zingiberaceae based on ITS sequences
Abstrak: The most recent infra-generic classification of Alpinia Roxb. by Smith divided the genus into two subgenera (Alpinia and Dieramalpinia) with 11 sections and 12 subsections. One of the sections of Alpinia subgenus Dieramalpinia is Myriocrater which contains about 16 species. The most recent phylogenetic study that included species from Alpinia subgenus Dieramalpinia was done by Kress et al. (2007). They sampled only eight species and found that these were nested within a clade referred to as the Alpinia carolinensis clade. This clade was well supported and may be separated as a genus if sampling more species confirms the result. The objectives of the present project are to compare ITS within one species; to test the monophyly of Alpinia section Myriocrater; to test whether adding more samples still supports the Alpinia carolinensis clade. The present study included thirty-nine samples representing nineteen taxa from Alpinia; seven samples are still unidentified at species level. Sequences of the Internal Transcribed Spacer were used in the analysis. The result showed that ITS sequence of Myriocrater’s species are more conserved than another group in Zingiberaceae. There are base variations within species level. The Alpinia section Myriocrater plus five species from other section is not monophyletic. The Alpinia carolinensis clade still includes three sections of Smith classification (Dieramalpinia, Myriocrater and Pycnanthus) from subgenus Dieramalpinia. Alpinia subgenus Dieramalpinia section Eubractea and one species of section Dieramalpinia are separated into another clade.
Keyword: Alpinia, Myriocrater, Dieramalpinia, Alpinia carolinensis clade