Application of NRCS-curve number method for runoff estimation in a mountainous watershed

Author

Faculty of Forestry, University Putra Malaysia, Serdang, Malaysia

Abstract

The major problem in the assessment of relationships between rainfall and runoff occurs when a study is carried out in ungauged watersheds in the absence of hydro-climatic data. This study aims to evaluate the applicability of Natural Resources Conservation Service-Curve Number (NRCS-CN) method together with GIS in estimating runoff depth in a mountainous watershed. The study was carried out in the semi-arid Kardeh watershed which lies between 36? 37? 17? to 36? 58? 25? N latitude and 59? 26? 3? to 59? 37? 17? E longitude, about 42 km north of Mashhad, Khorasan Razavi Province, Iran. The hydrologic soil groups, land use and slope maps were generated with GIS tools. The curve number values from NRCS Standard Tables were assigned to the intersected hydrologic soil groups and land use maps to generate CN values map. The curve number method was followed to estimate runoff depth for selected storm events in the watershed. Nash-Sutcliffe efficiency, pair-wise comparison by the t-test, Pearson correlation and percent error were used to assess the accuracy of estimated data and relationship between estimated and observed runoff depth. The results showed relatively low Nash-Sutcliffe efficiency (E = ? 0.835). There was no significant difference between estimated and observed runoff depths (P > 0.05). Fair correlation was detected between estimated and observed runoff depth (r = 0.56; P < 0.01). About 9% of the estimated runoff values were within ?10% of the recorded values and 43% had error percent greater than ?50%. The results indicated that the combined GIS and CN method can be used in semi-arid mountainous watersheds with about 55% accuracy only for management and conservation purposes.

Keywords


Akhondi, S. (2001) An investigation of curve number model in flood estimation using Geographical Information System (GIS). MSc thesis. Tarbiat Modares University, Iran.

 

 

Beckers, J., Smerdon, B. and Wilson, M. (2009) Review of hydrologic models for forest management and climate change applications in British Columbia and Alberta. forrex Forum for Research and Extension in Natural Resources, Kamloops, BC forrex Series 25. Available from: www.forrex.org/publications/forrexseries/fs25.pdf [accessed September 2010].

Ebrahimian et al., 113

 

Boughton, W. and Francis, C. (2007) Estimating runoff in ungauged catchments from rainfall, PET and the AWBM model. Environ Modell softw.22, 476-487.

 

Engel, B., Kyoung, J. L., Tang, Z., Theller L., Muthukrishnan S. (2004) WHAT (Web-based Hydrograph Analysis Tool). Available from: http://cobweb.ecn.purdue.edu/~what/ [accessed June 2009].

 

Gandini, M.L. and Usunoff E.J. (2004) SCS Curve Number estimation using remote sensing NDVI in a GIS environment. Environ Hydrol. 12, 1-9.

 

Jacobs, J.H. and Srinivasan, R. (2005) Effects of curve number modification on runoff estimation using WSR-88D rainfall data in Texas Watersheds. J Soil Water Conserv. 60, 274-278.

 

General Office of Natural Resources (1995) Watershed Management Plan for the Kardeh Dam Watershed. Report. 50p.

 

Khorasan Razavi province, Iran. [in Persian] Khojini, A. (2001) Investigation on the applicability of the SCS-CN method in runoff depth and peak discharge estimation in representative watersheds of Alborz Mountain chain. J Res Recon.3, 12-15. [in Persian]

 

Krause P., Boyle D. P., and Base F. (1975) Comparison of different efficiency criteria for hydrological model assessment. Adv Geosci. 5, 89–97.

 

Malekian A., SaraviMohseni M. and Mahdavi M. (2005) Applicability of the USDA-NRCS Curve Number method for runoff estimation. Iranian J Nat Resour. 57, 621-633. [in Persian]

 

Mellesse A.M and Shih S.F. (2002) Spatially distributed storm runoff depth estimation using Landsat images and GIS. Comput Electron Agr. 37, 173-183.

 

Nash, J. E. and Sutcliffe, J. V. (1970) River flow forecasting through conceptual models, Part I - A discussion of principles, J Hydrol. 10, 282–290.

 

Nassaji M. and Mahdavi M. (2005) The determination of peak-flood using different curve number methods (case study, Central Alborze area). Iranian J Nat Resour. 58, 315-324. [in Persian]

 

 Nayak, T.R. and Jaiswal R.K. (2003) Rainfall-runoff modelling using satellite data and GIS for Bebas River in Madhya Pradesh. IE (I) Journal. 84, 47-50.

 

Pandey, A. and Sahu A. K. (2002) Generation of curve number using remote sensing and geographic information system. Available from: www.GISdevelopment.net [accessed May 2009].

 

Pandey, A., Chowdary, V.M., Mal, B.C. and Dabral P.P. (2003) Estimation of runoff for agricultural watershed using SCS curve number and geographic information system. In: Proceedings of Map India Conference. Available from: Htpp://www.GISdevelopment.net [accessed May 2009].

 

Regional Water Authority (2001) Climatology of the Kardeh Dam. report. 180p. Khorasan Razavi province, Iran [in Persian].

 

Sadeghi S.H.R., Mahdavi M., Razavi S. L. (2008) Importance of calibration of maximum storage index coefficient and curve number in SCS model in Amameh, Kasilian, Darjazin and Khanmirza watersheds. I J Water Manage Sci Eng. 2, 12-24. USDA/NRC (1986) Urban Hydrology for Small Watersheds TR-55.

 

Technical Release 55. Washington DC. pp. 132-139. USDA-SCS (1993) Storm rainfall depth. In: National Engineering Handbook Series, Part 630, Chapter 4, Washington DC, USA.

 

Xianzhao L., Jiazhu L. (2008). Application of SCS model in estimation of runoff from small watershed in Loess Plateau of China. Chin Geogr Sci. 18, 235–241.

 

Watershed Management Department (1996) Evaluation of land capability and soil of the Kardeh watershed. Khorasan Razavi province, Iran. [in Persian]

 

Zhan, X. and Huang M.L. (2004) ArcCN-Runoff: An ArcGIS Tool for Generating Curve Number and Runoff Maps. Environ Modell Softw. 19, 875–879.