Implementation of the curve number method and the KINFIL model in the Smeda Catchment to mitigate overland flow with the use of terraces

The Smeda catchment, where the Smeda Brook drains an area of about 26 km2, is located in northern Bohemia in the Jizerské hory Mts. This experimental mountain catchment with the Bily Potok downstream gauge profile was selected as a model area for simulating extreme rainfall-runoff processes, using the KINFIL model supplemented by the Curve Number (CN) method. The combination of methods applied here consists of two parts. The first part is an application of the CN theory, where CN is correlated with hydraulic conductivity Ks of the soil types, and also with storage suction factor Sf at field capacity FC: CN = f(Ks, Sf). The second part of the combined KINFIL/CN method, represented by the KINFIL model, is based on the kinematic wave method which, in combination with infiltration, mitigates the overland flow. This simulation was chosen as an alternative to an enormous amount of field measurements. The combination used here was shown to provide a successful method. However, practical application would require at least four sub-catchments, so that more terraces can be placed. The provision of effective measures will require more investment than is currently envisaged.