Evaluation of Infiltration Rate Variation Effected by Suspended Solids in an Artificial Recharge Basin in Moosian Plain in Dehloran, West of Iran

Saeed Boroomand Nasab, Mohammad Albaji and Ayoub Pirani

Irrigation and Drainage Dept, Faculty of Water Sciences Engineering, Shahid Chamran University, P.O.Box: 61357-8-3151 Ahwaz, Iran.

Corresponding author: Mohammad Albaji, Irrigation and Drainage Dept, Faculty of Water Sciences Engineering, Shahid Chamran University, P.O.Box: 61357-8-3151 Ahwaz, Iran.
 E-mail: m_albaji2000@yahoo.co.uk

Abstract

In this study a floodwater-spreading system, which was constructed and started to work in 1997 on the eastern part of the Dehloran colluvial plain, was selected to measure and monitor the variation of the infiltration and clogging phenomenon. The vertical variation as well as flow direction variation of the infiltration was studied.  The vertical variation of infiltration of the sediment was measured at five surfaces, (1) the surface of the whole sediment deposited since 1997 when the system started to operate, (2) the surface where the new deposited sediment is removed, (3) the surfaces when 10,(4) 20, and (5) 30 cm of the previous natural sediment were removed.  To monitor infiltration in the flow direction, infiltration was measured in the desilting basin, spreading channel, spreading basin, and control points. A Double ring method was used to measure infiltration at these surfaces.  The statistical analyses were done using SPSS and MSTATC statistical packages.  The statistical procedures used for the analyses were analysis of variance (ANOVA), least square difference (LSD) and Duncan methods.  The statistical analysis showed that the sedimentation significantly decreased the surface infiltration of the desilting basin when compared with the data obtained from the control points.  The control points were selected in an intact area where the soil and geomorphic surface were similar to the selected sites.  Removal of the top 10 cm of the natural surface beneath the sediment showed that the infiltration rates were significantly increased.  The results found here suggests that to decrease the adverse effects of sedimentation on the infiltration rate in the desilting basin, recent sediment of the basin should be removed  and the top 10cm of the natural surface should be  plowed  below the removed sediment.  The plowing reduces the clogging phenomenon of the sediment. 

Key words: Floodwater spreading, Infiltration, Clogging.