Judul: Perbandingan Metode Koreksi Data Radar Cuaca Dengan Penakar Hujan Wilayah Bengkulu
Abstrak: Weather radar data can provide spatio temporal rainfall forecast at high- resolution. Radar covers a large area and captures the spatial variability of rainfall that increases a short-term predictability of rain. However, the rainfall derived from radar is inherently an estimated value that may contain bias. Also, the estimated value is derived indirectly from the radar reflectivity equation. Therefore, adjusting the estimated rainfall value based on the local observed rain gauge remains a research challenge. This study employed Bengkulu weather radar data and combined with the rainfall from automatic weather station at the Bengkulu Climatology Station. Observed rainfall datasets from 34 rain gauges over Bengkulu for 2015 to 2020 were used for the analysis, we selected December-February as representative of wet season, whereas June-August was for the dry season. Correction of radar data with rain gauge is calculated using the Mean Field Bias (MFB), Local Bias Correction (LBC), and Quantile Mapping (QM) approaches. MFB is a method for estimating the overall bias (average) for radar in a large domain. The LBC correction is a correction by considering the distance factor of the rain gauge to the radar location. Correction of bias QM corrects the data distribution using the probability approach. The Conversion of reflectivity to intensity using three different Z-R relationship, namely Marshall Palmer, Rosenfeld, and the new Z-R equation refers to previous research on the island of Sumatra. The results of analyses in the present study strongly indicated an improvement in radar data quality after the correction method was applied. The Local Bias Correction (LBC) method gives the best results compared to the MFB and QM methods for the Bengkulu region, with the highest correlation of 0.51. The best Z-R relationship is obtained from the Marshall Palmer equation. Bias correction performance in the wet season (DJF) has better results than in the dry season (JJA).
Keyword: Reflectivity, radar, correction, rain, method

Judul: Pendugaan Debit Aliran memanfaatkan Radar Cuaca dan Model Hidrologi di DAS Ciliwung Hulu (Kasus Stasiun Katulampa)
Abstrak: diaproksimasi menggunakan persamaan reflektiviti radar Z-R. Bias data radar disebabkan beragam faktor seperti atenuasi sinyal radar dan profil radar vertikal. Produk data radar QPE BMKG dikalibrasi dengan data penakar hujan Hillman di lima lokasi menggunakan metode Window Probability Matching Method (WPMM). Kernel berukuran 3x3 piksel digunakan untuk mendapatkan nilai ratarata reflektiviti radar secara spasial di masing-masing titik lokasi penakar hujan dengan periode waktu satu jam. Bias pada produk data radar kemudian dikoreksi menggunakan metode Static Gauge Adjustment (SGA) dan Mean Field Bias (MFB). Dari dua metode ini, metode MFB secara signifikan mampu mereduksi galat. Curah hujan estimasi dari data radar bersifat underestimate dan beragam dari waktu ke waktu selama periode pengamatan. Produk data radar QPE terkoreksi yang diperoleh menggunakan metode WPMM belum mampu meningkatkan akurasi curah hujan di lima titik lokasi penakar hujan. Masih diperlukan metode penyesuaian untuk lebih meningkatkan akurasi estimasi data radar. Parameter yang paling sensitif dalam model HEC-HMS adalah aliran dasar awal (initial baseflow). Nilai NSE (Nash and Sutcliffe Efficiency) pada proses kalibrasi sangat baik (NSE > 0,75) dan pola debit model mengikuti pola debit observasi lapangan. Model HEC-HMS cukup baik untuk memprediksi waktu debit puncak dan debit puncak. Pada proses validasi nilai NSE bervariasi dari tidak memuaskan (NSE <0,50) hingga memuaskan (0.50 <NSE <0,65) dan pola model cukup baik untuk memprediksi waktu debit puncak namun beragam dalam memprediksi debit puncak.
Keyword: Sub-DAS Ciliwung Hulu, pemodelan hidrologi, Mean Field Bias (MFB), data radar QPE, Static Gauge Adjustment (SGA), persamaan Z-R

Judul: Embriogenesis ikan buta (Astyanax fasciatus)
Abstrak: Ikan buta Astyanax fasciatus adalah spesies ikan unik dari famili Characidae yang menempati perairan dalam gua di Wilayah La Cueva Chica-San Luis Potasi-Mexico. Ikan ini memiliki mata yang tereduksi (Blind Cavefish) dan warna kulit merah muda, pucat serta mengkilap.
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