Curve Number Estimation for Ungauged Watershed in Semi-Arid Region

Denik Sri Krisnayanti, Wilhelmus Bunganaen, John H. Frans, Yustinus A. Seran, Djoko Legono


The Benanain Watershed is located in East Nusa Tenggara with an area of 3,181 km2 and is divided into 29 sub-watersheds. The East Nusa Tenggara itself is an eastern region of Indonesia with a unique climate condition called semi-arid. The high rainfall intensity occurring in short duration results in large surface runoff and erosion. Floods and erosion in semi-arid areas due to sensitive soils to drought and heavy rainfall extremely. This paper presents the application of the Soil Conservation Services-Curve Number (SCS-CN) real-flood flows through a digital map of soil type, land use, topography, and the heterogeneity of physical condition, especially for ungauged watersheds. The method used is an approach empirical to estimate runoff from the relationship between rainfall, land use, and soil hydrology groups. This watershed has a large area that must analyze every sub-watershed. The land-use of the Benanain watershed is secondary dryland forest by 44.26% and the hydrological soil group on the B group classification with medium to high absorption potential by 46.502% from the total area. The curve number value of the Benanain Watershed ranges from 56.54 to 73.90, where the mean CN value of 65.32. The rainfall (mm) for the 29 sub-watersheds in the Benanain Watershed has decreased by about 74.65% when being surface runoff or only 25.35% of water becomes surface runoff. The relationship between rainfall depth and CN is classified as standard response and trend line (flat slope) equilibrium occurs when rainfall depth value of 56.71 mm and CN is close to 66.30. The high variability of intense rainfall between the rainy season and the dry season had a significant influence on the curve number value in a large watershed area. Further analysis will be more accurate if it is supported by long rainfall data and observation runoff data as a control.


Doi: 10.28991/cej-2021-03091711

Full Text: PDF


SCS-CN Method; Soil Type; Land Use; Standard Response.


Salem, B. B. "Arid zone forestry: a guide for field technicians." FAO Conservation Guide 20 (1989).

Oldeman, L. R., and M. Frere. “Technical Report on a Study of the Agroclimatology of the Humid Tropics of Southeast Asia.” Food & Agriculture Org., United Nation, Rome (1982).

Roshetko J, Mulawarman, WJ Santoso dan IN Oka. Wanatani di Nusa Tenggara. Prosiding Lokakarya Wanatani Se-Nusa Tenggara (November 11-14, 2001). ICRAF dan Winrock International. Bogor.

Sardjono, M.A., Djogo, T., Arifin, H.S. and Wijayanto, N. Klasifikasi dan Pola Kombinasi Komponen Agroforestri, World Agroforestry Centre (ICRAF) Southeast Asia Regional Office, Bogor, Indonesia, (2003).

Solangi, Ghulam Shabir, Altaf Ali Siyal, and Pirah Siyal. “Spatiotemporal Dynamics of Land Surface Temperature and Its Impact on the Vegetation.” Civil Engineering Journal 5, no. 8 (August 21, 2019): 1753–1763. doi:10.28991/cej-2019-03091368.

Monk KA, Y de Fretes, and G Reksodiharjo-Lilley. The ecology of Nusa Tenggara and Maluku. The ecology of Indonesia series, volume 5. Dalhousie University, Nova Scotia, Canada, (1997).

Adidarma, Wanny K. “Teknik Perhitungan Banjir Desain Untuk Bendungan Dengan Data Terbatas Khususnya di Indonesia (Technique to Determine Inflow Design Flood for Dams with Limited Data).” Jurnal Teknik Hidraulik (December 2013) 4(2): 105-116. doi:10.32679/jth.v4i2.501

NEH (National Engineering Handbook), Chapter 9 and 10: Estimation of Direct Runoff from Storm Rainfall, Part 630 Hydrology National Engineering Handbook, USDA, Washington DC, 2004c.

Ideawati L. F, Limantara L.M, Andawayanti U. “Analisis Perubahan Bilangan Kurva Aliran Permukaan (Runoff Curve Number) Terhadap Debit Banjir Di Das Lesti.” Jurnal Teknik Pengairan (2015). 7(1): 150-159.

Ramadan, A.N.R., Adidarma, W.K., Riyanto, B.A., and Windiantita, K. “Determination of Hydrologic Soil Group for The Calculation of Floods at Upper Brantas watershed.” Jurnal Sumber Daya Air (November 2017). 13(2): 69-82.

Liu, Xianzhao, and Jiazhu Li. “Application of SCS Model in Estimation of Runoff from Small Watershed in Loess Plateau of China.” Chinese Geographical Science 18, no. 3 (September 2008): 235–241. doi:10.1007/s11769-008-0235-x.

Rizal, Nanang Saiful, and Kus Farukah. "Determination of Correction Value Curve Number (CN) on Watershed with Shape Oval Using HEC HMS Models." In Proceedings of the International Conference on Green Technology 8, no. 1, (2017): 222-234.

Welkis, D. Frangky B., Ferry Moun, Iki Lobo, and Denik Sri Krisnayanti. “Characteristics of Flood Water Level Based on Hydrologic Soil Group Analysis in Temef Watershed.” IOP Conference Series: Earth and Environmental Science 437 (February 11, 2020): 012005. doi:10.1088/1755-1315/437/1/012005.

Nageswara Rao, K. “Analysis of Surface Runoff Potential in Ungauged Basin Using Basin Parameters and SCS-CN Method.” Applied Water Science 10, no. 1 (January 2020). doi:10.1007/s13201-019-1129-z.

Psomiadis, Emmanouil, Konstantinos X. Soulis, and Nikolaos Efthimiou. “Using SCS-CN and Earth Observation for the Comparative Assessment of the Hydrological Effect of Gradual and Abrupt Spatiotemporal Land Cover Changes.” Water 12, no. 5 (May 13, 2020): 1386. doi:10.3390/w12051386.

Bilaşco, ST. “Calculation of the Maximum Runoff Volume Induced by Torrential Rainfalls through the GIS SCS-CN Method. Case Study: The Small Hydrographic Basins in the South and West of the Someşan Plateau.” (April 2010). Studia Universitatis Babeş-Bolyai, Geographia, LV, 1.

Chanu, S. N., Kumar, P., Thomas, A. “Estimation of curve number and runoff of a micro-watershed using soil conservation service method.” Journal of Soil and Water Conservation (October 2015). 14(4): 317-325.

Kumar Mishra, Surendra, Sarita Gajbhiye, and Ashish Pandey. “Estimation of Design Runoff Curve Numbers for Narmada Watersheds (India).” Journal of Applied Water Engineering and Research 1, no. 1 (June 2013): 69–79. doi:10.1080/23249676.2013.831583.

Nonglait, T.L. “Application of SCS-CN for Estimation of Runoff in A Humid Micro watershed.” International Journal of Current. Agriculture Sciences (October 2016). 6(10): 121-127.

Supriya, S., Ravikumar, A.S. “Estimation of Run-off By SCS-CN Method of Kollegal Taluk, Chamarajanagar, Karnataka State, Using RS and GIS Techniques.” International Conference Paper of 24th Hydro (December 2019,18-20). India.

Widiyati, C.N., Sudibyakto. “Application of US-SCS Curve Number Methode and GIS for Determining Suitable Land Cover of Small Watershed.” Indonesian Journal of Geography (June 2010). 42(1): 69-90.

Elhakeem, Mohamed, and Athanasios N. Papanicolaou. “Estimation of the Runoff Curve Number via Direct Rainfall Simulator Measurements in the State of Iowa, USA.” Water Resources Management 23, no. 12 (January 17, 2009): 2455–2473. doi:10.1007/s11269-008-9390-1.

Kincl, David, David Kabelka, Jan Vopravil, and Darina Heřmanovská. “Estimating the Curve Number for Conventional and Soil Conservation Technologies Using a Rainfall Simulator.” Soil and Water Research 16, no. No. 2 (April 9, 2021): 95–102. doi:10.17221/114/2020-swr.

Woodward, Donald E., Richard H. Hawkins, Ruiyun Jiang, Allen T. Hjelmfelt, Jr., Joseph A. Van Mullem, and Quan D. Quan. “Runoff Curve Number Method: Examination of the Initial Abstraction Ratio.” World Water & Environmental Resources Congress 2003 (June 17, 2003). doi:10.1061/40685(2003)308.

Banasik, Kazimierz, Adam Krajewski, Anna Sikorska, and Leszek Hejduk. “Curve Number Estimation for a Small Urban Catchment from Recorded Rainfall-Runoff Events.” Archives of Environmental Protection 40, no. 3 (December 11, 2014): 75–86. doi:10.2478/aep-2014-0032.

Krisnayanti, Denik Sri, Davianto Frangky B. Welkis, Fery Moun Hepy, and Djoko Legono. “Evaluasi Kesesuaian Data Tropical Rainfall Measuring Mission (TRMM) Dengan Data Pos Hujan Pada Das Temef Di Kabupaten Timor Tengah Selatan.” Jurnal Sumber Daya Air 16, no. 1 (May 31, 2020): 51–62. doi:10.32679/jsda.v16i1.646.

WUR. n.d. “The Curve Number Method.”. Available online: (accessed on January 2021).

Mishra, S. K., Vijay P. Singh, and P. K. Singh. “Revisiting the Soil Conservation Service Curve Number Method.” Water Science and Technology Library (2018): 667–693. doi:10.1007/978-981-10-5801-1_46.

Hawkins, Richard H. “Asymptotic Determination of Runoff Curve Numbers from Data.” Journal of Irrigation and Drainage Engineering 119, no. 2 (March 1993): 334–345. doi:10.1061/(asce)0733-9437(1993)119:2(334).

Velásquez-Valle, Miguel A., Ignacio Sánchez-Cohen, Richard H. Hawkins, Alfonso Serna-Pérez, Ramón Gutiérrez-Luna, and Aurelio Pedroza-Sandoval. “Rainfall-Runoff Relationships in a Semiarid Rangeland Watershed in Central Mexico, Based on the CN-NRCS Approach.” Modeling Earth Systems and Environment 3, no. 4 (September 22, 2017): 1263–1272. doi:10.1007/s40808-017-0379-8.

Soil Conservation Service. National engineering handbook, Section 4, Hydrology. Department of Agriculture, Washington, (1972): 762 p.

Full Text: PDF

DOI: 10.28991/cej-2021-03091711


  • There are currently no refbacks.

Copyright (c) 2021 Denik Sri Krisnayanti, Wilhelmus Bunganaen, John H. Frans, Yustinus Akito Seran, Djoko Legono

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.