Aplikasi Metode Curve Number Untuk Mempresentasikan Hubungan Curah Hujan Dan Aliran Permukaan Di Das Ciliwung Hulu – Jawa Barat

Abstract

Aliran permukaan/limpasan (run off) merupakan salah satu variabel hidrologi yang sangat penting di dalam menunjang kegiatan pengembangan sumber daya air. Metode prediksi yang handal untuk menghitung jumlah dan laju limpasan yang berasal dari permukaan tanah dan bergerak menuju sungai di suatu DAS yang tidak dilengkapi alat ukur (ungaged watershed) adalah suatu pekerjaan yang sangat sulit dan memerlukanwaktu yang banyak. Penelitian ini dilakukan di DAS Ciliwung Hulu, yang merupakan daerah penting dalam kotribusi banjir di Jakarta. Untuk mengetahaui run off yang terjadi, digunakan data curah hujan dan debit Tahun 2007-2009. Sebagai model, untuk mengetahui run off menggunakan peta penggunaan lahan, peta jenis tanah, dan topografi. Peta-peta tersebut diolah dengan menggunakan Arcview, sehingga didapatkannilai CN. Berdasarkan analisis perhitungan, besarnya debit mendekati 50% dari tebal hujan. Kondisi ini mengindikasikan bahwa kondisi DAS Ciliwung Hulu sudah tidak mampu lagi menyerap curah hujan dengan baik. Korelasi antara hasil prediksi run off model yang menggunakan CN dengan perhitungan run off observasi cukup baik. Hal ini menunjukkan bahwa metode Curve Number cukup dapat mepresentaskan hubungancurah hujan dengan aliran permukaan (run off). kata kunci : Run off observasi, run off model, curve number AbstractRun off (surface flow) is one of the most important hydrological variable in supporting the activities of water resources development. A reliable prediction method to calculate the amount and rate of runoff from the land surface caused by the rain that falls in a watershed that is not equipped with measuring devices (un gauge watershed) is a verydifficult job and requires a lot of time. The research was conducted in the watershed Ciliwung Hulu, which is an important area in relation to the incidence of flooding in Jakarta. Curve Number (CN) method can be used to predict the amount of runoff from a watershed. This model required input of rainfall; land cover maps; soil type maps,and topography. The maps are processed using Arc View software, so we get the value of CN. In this study, we used of rainfall and discharge data 2007-2009. Based on the analysis of calculation, known that amount of surface flow approaching 50% of rainfall depth. This condition indicates that the Ciliwung Hulu watershed conditions were not ableand proper to absorb of rainfall. The correlation between the results of run-off prediction models using CN with run-off observation was quite good. This indicated that the Curve Number method could be able to represent the relationship of rainfall with surface flow (run off) and also to predict runoff key words: Run off observation, run-off model, curve number

Determination of Curve Number for the Temef Watershed, Timor Tengah Selatan Regency

“…The CN method is an empirical approach used to calculate direct runoff from rainfall occurrences, starting from the rainfall catchment area (watershed) [11]. The CN method estimates the runoff from the relationships among rainfall, ground cover, and hydrologic soil group (cover complex classification) [12]. The CN value may be estimated if the watershed's soil classification and ground cover are known.…”

Kajian Nilai Curve Number pada Daerah Aliran Sungai Manikin di Kabupaten Kupang

“…Penelitian tentang nilai curve number sudah banyak dilakukan di DAS-DAS yang ada di Indonesia seperti DAS Ciliwung Hulu (Tikno dkk., 2012); DAS Garang Semarang (Sarminingsih dkk., 2019); DAS Temef di Nusa Tenggara Timur (Welkis dkk., 2020); dan DAS Benanain (Krisnayanti dkk;2021). Penelitian ini bertujuan untuk mengetahui nilai curve number di DAS Manikin.…”

Prediction of Peak Discharge Using the SCS Curve Number Method in the Manikin Watershed

“…The primary role of remote sensing technology in runoff calculations is typically to generate input data and assist in calculating model coefficients and parameters. Experience has shown that various thematic information sources can be obtained through the interpretation of satellite imagery, including data related to land cover, soil, vegetation, and drainage patterns [2]. By combining the results of satellite image interpretation with traditional measurements, such as rainfall, temperature, and topography, new data for rainfall-runoff modeling is generated.…”