Articles | Volume 370
11 Jun 2015
 | 11 Jun 2015

Determination of Curve Number for snowmelt-runoff floods in a small catchment

L. Hejduk, A. Hejduk, and K. Banasik

Abstract. One of the widely used methods for predicting flood runoff depth from ungauged catchments is the curve number (CN) method, developed by Soil Conservation Service (SCS) of US Department of Agriculture. The CN parameter can be computed directly from recorded rainfall depths and direct runoff volumes in case of existing data. In presented investigations, the CN parameter has been computed for snowmelt-runoff events based on snowmelt and rainfall measurements. All required data has been gathered for a small agricultural catchment (A = 23.4 km2) of Zagożdżonka river, located in Central Poland. The CN number received from 28 snowmelt-runoff events has been compared with CN computed from rainfall-runoff events for the same catchment. The CN parameter, estimated empirically varies from 64.0 to 94.8. The relation between CN and snowmelt depth was investigated in a similar procedure to relation between CN and rainfall depth.

Short summary
This paper presents an attempt for application of the CN method for snowmelt runoff events based on measured snow water content, rainfall and runoff in a small lowland catchment. The CN calculated from measured snowmelt-runoff events show a large variation from 64 to 94.8 with the average value calculated as 79.3. The comparison of CN and MP suggests decreasing the relation in a similar way to decreasing the CN and rainfall relation already investigated in this catchment.