Influence of roughness changes on offtaking discharge in irrigation canals

Shahrokhnia, Mohammad Ali; Javan, Mitra

doi:10.1007/s11269-006-9034-2

Cited by 12 publications

(6 citation statements)

References 11 publications

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“…One-dimensional (1D) hydraulic models have a long tradition of application, especially being applied to elucidate the bulk hydraulic characteristics of large single-thread rivers (Pappenberger et al, 2005;Remo and Pinter, 2007;Roberts et al, 2007;Shahrokhnia and Javan, 2007;Thompson et al, 2007;Patro et al, 2009). However, to understand how a river behaves when there is a network of interconnecting channels, often with more than one outlet section, remains a challenge.…”

Section: Introductionmentioning

confidence: 99%

Modelling the bulk flow of a bedrock‐constrained, multi‐channel reach of the Mekong River, Siphandone, southern Laos

Van

Carling

Atkinson

2012

Earth Surf Processes Landf

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The general nature of bulk flow within bedrock single‐channel reaches has been considered by several studies recently. However, the flow structure of a bedrock‐constrained, large river with a multiple channel network has not been investigated previously. The multiple channel network of the Siphandone wetlands in Laos, a section of the Mekong River, was modelled using a steady one‐dimensional hydraulic model. The river network is characterized by a spatially‐varying channel‐form leading to significant changes in the bulk flow properties between and along the channels. The challenge to model the bulk flow in such a remote region was the lack of ideal boundary conditions. The flow models considered both low flow, high inbank and overbank flows and were calibrated using SPOT satellite sensor imagery and limited field data concerning water levels. The application of the model highlighted flow characteristics of a large multi‐channel network and also further indicated the field data that would be required to properly characterize the flow field empirically. Important results included the observation that adjacent channels within the network had different water surface slopes for the same moments in time; thus calibration data for modelling similar systems needs to account for these significant local differences. Further, the in‐channel hydraulic roughness coefficient strongly varied from one cross‐section to the next (Manning's ‘n’ range: 0·01 to 0·10). These differences were amplified during low flow but persisted in muted form during high discharges. Copyright © 2012 John Wiley & Sons, Ltd.

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Section: Introductionmentioning

confidence: 99%

Modelling the bulk flow of a bedrock‐constrained, multi‐channel reach of the Mekong River, Siphandone, southern Laos

Van

Carling

Atkinson

2012

Earth Surf Processes Landf

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“…Table shows the performance indicators of DIN ( P A , P F , P E , P D ) in 2001 reported by Shahrokhnia and Javan (). The overall performance indicators (OPIs) were measured in the present study.…”

Section: Resultsmentioning

confidence: 99%

“…Comparison between the four canals studied using the overall performance indicators showed that the RBPC canal had the highest and the LBPC canal the lowest water delivery performance. Table IV shows the performance indicators of DIN (P A , P F , P E , P D ) in 2001 reported by Shahrokhnia and Javan (2007). The overall performance indicators (OPIs) were measured in the present study.…”

Section: Performance Indicators In 2015mentioning

confidence: 88%

“…Shahrokhnia and Javan () evaluated DIN using a hydraulic simulation model and showed that the gate‐opening rules used for system operation caused considerable discharge changes in water distribution. Shahrokhnia and Javan () showed that the influence of canal roughness changes on offtake discharge and performance in DIN could be significant. Shahrokhnia and Javan () evaluated the influence of inaccurate cross‐regulator setting on water distribution in DIN.…”

Section: Introductionmentioning

confidence: 99%

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Determination of Overall Water Delivery Performance Based on Adequacy, Efficiency, Equity and Dependability in the Doroodzan Irrigation Network

Shahrokhnia

Olyan‐Ghiasi

2019

Irrigation and Drainage

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Evaluation of irrigation and drainage systems can help managers find problems and deliver water in the system more efficiently. Adequacy, efficiency, equity and dependability are important indicators for evaluation of management in irrigation and drainage systems. Evaluation of overall performance based on the above‐mentioned four indicators can be useful for more accurate judgement about system performance. In this paper, a new simple overall water delivery performance indicator (OPI) and a general form (OWDPI) are defined based on the combination of the four previously mentioned indicators, adequacy, efficiency, equity and dependability. Three performance classes were also defined to represent standard values. The overall performance indicator was used for evaluation of the Doroodzan Irrigation Network (DIN) in south‐western Iran. Results showed that although adequacy in 2001 and efficiency in 2015 were good for DIN, the overall delivery performance indicator was poor and equal to 0.70 and 0.72 in the 2 years of study. The developed overall performance indicator may be a suitable tool for better evaluation and comparison of DIN and other similar irrigation and drainage systems around the world. © 2019 John Wiley & Sons, Ltd.

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“…It was observed that the actual depth and discharge in the canal is significantly different from the design ones. Shahrokhnia and Javan [15] evaluated the influence of changes in the canal roughness on offtakes discharge using HEC-RAS modeling software. They indicated that these changes could be could be considered as an important factor in better water distribution of irrigation canals.…”

Section: Introductionmentioning

confidence: 99%

Hydraulic Performance of Improved Irrigation System

Mohamed

Elham

Samir

et al. 2019

JES. Journal of Engineering Sciences

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Irrigation canals network in Egypt for all levels suffer from water deficit and un-equitable distribution of irrigation water among beneficiaries. So, its modernization became omnipresent to overcome the problem of water shortage by the end of canals. One of the improvement sectors of irrigation canals network is replacing an earthen mesqa by upraised lines or buried pipes. The hydraulic performance of the improved irrigation system is explored using a case study canal, where buried pipes system is applied as improved mesqa system. The case study is for the Hadaya canal which is one of the distributary canals that located in Assiut governorate. This canal services 19 mesqas with different lengths and area served. The hydraulic performance of mesqas is examined through different scenarios of operation of the mesqa pumping station and area served. Three scenarios of mesqa valves operation are considered .The first scenario is when all valves are operated at the same time all over the week. The second is when one valve operates for two days per week and the third is when all valves operate for one day. Also, three scenarios are considered for pump operation 14, 16 and 18 hours per day. Moreover, effect of different scenarios of mesqa operation on sudden transition of flow in pipes due to pump shutdown is studied. EPANET software was used for the hydraulic analysis. It was found that operating the pump 14 hours per day fulfill the minimum monthly cost. Also, operating the outlet valves according to scenario no. (3) gives the least operating cost. The maximum velocity in the pipeline is less than 1.2 m/s for all operating scenarios. Besides, effects of mesqas off-takes on the flow in distributary canal are studied.

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Influence of roughness changes on offtaking discharge in irrigation canals

Cited by 12 publications

References 11 publications

Modelling the bulk flow of a bedrock‐constrained, multi‐channel reach of the Mekong River, Siphandone, southern Laos

Modelling the bulk flow of a bedrock‐constrained, multi‐channel reach of the Mekong River, Siphandone, southern Laos

Determination of Overall Water Delivery Performance Based on Adequacy, Efficiency, Equity and Dependability in the Doroodzan Irrigation Network

Hydraulic Performance of Improved Irrigation System

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