MODEL GR4J (Ge’nie Rural a’ 4 Parame’tres Journalier) UNTUK MENDUKUNG ANALISIS KETERSEDIAAN AIR DI DAS TAJUM

Nur Azizah, Purwanto Bekti Santoso, Mr. Nastain

Abstract


This study aims to apply the GR4J model as rainfall-runoff modeling in Tajum watershed to get four free parameters obtained from daily rainfall data. In this study, input data is in the form of daily rainfall data and potential evapotranspiration data. The output of calculated discharged is calibrated using observations of daily discharge data. This modeling optimizes four free parameters of the Maximum Capacity of Production Store (X 1), Groundwater Coefficient (X 2), Maximum Capacity of Routing Store (X 3), and Peak Time of Ordinate Unit Hydrograph (X 4). The optimum values of the modeling parameters of GR4J are obtained from the criterion of the smallest discrepancies between calculated and observed data, which are Nash-Sutcliffe Coefficient (NS), the correlation coefficient values and methods of Relative Volume Error (RVE). There are three stages in this modeling, namely: model calibration, model verification and model validation. Model calibration is carried out by using the first five years of data and verification of models uses the second five years of data. Comparisons of GR4J with other two rainfall-runoff models, Mock and SAC-SMA Models, were also carried. Results of this study indicate that GR4J model shows better performance than the Mock models and SAC-SMA models in terms of the criterion evaluated.

Keywords: Tajum watershed, water availability, rainfall-runoff, GR4J models

References


Botti, N., 2010. Uji Kehandalan Model Mock Untuk Analisis Ketersediaan Air di DAS Tajum. Laporan Tugas Akhir. Jurusan Teknik Sipil, Fakultas Sains dan Teknik, UNSOED, Purwokerto.

Dhemi et.al, 2008. Penentuan Debit Harian Menggunakan Pemodelan Rainfall Runoff GR4J Untuk Analisa Unit Hidrograf Pada DAS Citarum Hulu. Departemen Teknik Sipil ITB, Bandung.

Edijatno, Michel, C., 1989, Un Modele Pluie-Debit Journalier a Trois Parameters, La Houille Blanche (2), 113 – 121.

Edijatno, 1999, GR3J: a daily watershed model with three free parameters, Journal of Hydrology.

Edy, S., 2010. Prediksi Debit Banjir Daerah Aliran Sungai Tajum Menggunakan Perangkat Lunak HEC-HMS. Laporan Tugas Akhir. Jurusan Teknik Sipil, Fakultas Sains dan Teknik, UNSOED, Purwokerto.

Nascimento, N.O., 1995, Appreciation a L’aide D’un Modele Emirique Des Effets D’action Anthropiques Sur La Relation Pluie-Debit a L’echelle Du Bassin Versant, PhD Thesis, CERGRENE/ENPC, Paris, France, 550 pp.

Nastain dan Purwanto, 2003. Pengaruh Alih Fungsi Lahan Kawasan Baturaden Terhadap Debit Alir Sungai Banjaran. Jurnal Ilmiah Unsoed, Lembaga Penelitian Unsoed, Purwokerto.

Perrin C., Michel, C., dan Andréassian, V., 2003. Improvement of a parsimonious model for streamflow simulation. Journal of Hydrology, 279:275–289.

Suroso dan Hery, 2004. Prakiraan Banjir Sungai Logawa Hilir Untuk Peringatan Dini Bahaya Banjir di Purwokerto Bagian Selatan. Laporan Hasil Penelitian, Lembaga Penelitian, UNSOED, Purwokerto.

Suroso dan Hery, 2005. Pengaruh Perubahan Tata Guna Lahan Terhadap Debit Banjir Studi Kasus Daerah Aliran Sungai Banjaran. Laporan Hasil Penelitian, Lembaga Penelitian, UNSOED, Purwokerto.


Full Text: ##common.PDF##

DOI: 10.30595/techno.v13i1.39

ISSN: 2579-9096