An advanced soil moisture accounting procedure for SCS curve number method

• DOI: 10.1002/hyp.6503
• Publication Date: 2007-02-02T18:50:51Z
• Authors: R. K. Sahu; S. K. Mishra; T. I. Eldho; M. K. Jain
• Keywords: 550; 0207 environmental engineering; Direct Surface Runoff; Soil Moisture Accounting; 02 engineering and technology; Initial Soil Moisture Store; 15. Life on land; Catchment; Scs-Cn Method; 6. Clean water; Rainfall-Runoff Models; Calibration; Rainfall-Runoff Modelling

AbstractThe Soil Conservation Service Curve Number (SCS‐CN) method has been a topic of much discussion, especially in the last three decades. Recently, Michel et al. (2005) pointed out several inconsistencies in the soil moisture accounting (SMA) procedure used in the SCS‐CN method and developed a procedure that is more consistent from the SMA viewpoint. However, the model proposed by them does not have any expression for initial soil moisture store level (V0) and hence there is a scope for further improvement. Like the original method, there is sudden jump in V0 and therefore a quantum jump in computed runoff is possible. In the present study, an attempt is made to develop an expression for V0 to make the model a continuous watershed model. Then, the performance of the new model is compared with the model proposed by Michel et al. and the original SCS‐CN model by applying them in a large number of small watersheds in the United States. The present model was found to perform significantly better than both the original SCS‐CN model and the model proposed by Michel et al. Copyright © 2007 John Wiley & Sons, Ltd.