Volume 18, Issue 69 (fall 2014)                   JWSS 2014, 18(69): 251-260 | Back to browse issues page

XML Persian Abstract Print

Young Res. Club, Khouzestan Sci. and Res. Branch, Islamic Azad University, Ahvaz, Iran , lalehzari@hotmail.com
Abstract:   (8858 Views)

Advance velocity is an important factor in surface irrigation system design and simulation. Volume balance is a simple model based on continuity equation used in surface irrigation design and management. In the past volume balance models, it is generally assumed that the upstream depth of surface water is constant and equal to normal depth. This initial assumption may cause significant errors in computing advance flow. In this paper, a modified volume balance (MVB) model is developed to predict the advance curve in furrow irrigation. In the suggested method the upstream surface, water depth is actual depth and variable in time. Predicted advance distance of VB, VB-ZI and MVB was compared to the observed data obtained for the three furrow lengths of 60, 80 and 90m. Evaluation indexes indicated that the modified volume balance equation is more accurate than the previous equations by RMSE 9.26, 7.37 and 6.76 respectively. Sensitivity analysis showed that the inlet discharge has the greatest effect on the model and the model is more sensitive to decreasing the discharge amount than to increasing it

Full-Text [PDF 2780 kb]   (1919 Downloads)    
Type of Study: Research | Subject: Ggeneral
Received: 2015/01/11 | Accepted: 2015/01/11 | Published: 2015/01/11