Experimental investigation of time-dependent local scour downstream of a stepped channel

Özgenç Aksoy A., Doğan M.

WATER SA, vol.45, no.3, pp.411-419, 2019 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 45 Issue: 3
  • Publication Date: 2019
  • Doi Number: 10.17159/wsa/2019.v45.i3.6738
  • Journal Name: WATER SA
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.411-419
  • Keywords: stepped channel, local scour, temporal variation
  • Dokuz Eylül University Affiliated: Yes


In this study, temporal variation of local scour occurring at the downstream part of the stepped channel were investigated experimentally. The experimental tests were carried out in a stepped flume with a height of 2.4 m. The width of the rectangular flume was 0.10 m and the length of the stilling basin was 2.12 m. Bed material was placed in a sediment box with a height of 24 cm and length of 2.48 m, without any compaction. Experiments were carried out by using bed material of 4 different grain size distributions, 2 different sill heights and 6 different flow rates. Two empirical equations which include Shields parameter (theta) and densimetric Froude particle number (F-d) were proposed by using the experimental findings to predict the temporal variation of the scour depth. The R-2 (coefficient of determination) values were computed for both proposed equations as 0.866 and 0.865. The scatter index (SI) values were also determined and computed as 8.73% and 8.25%. The fit of the equations was also determined by means of Fisher's test.