Initial-Inflow-Variation Impacts on Furrow Irrigation Evaluation

Renault, D.; Wallender, W. W.

doi:10.1061/(asce)0733-9437(1996)122:1(7)

Cited by 11 publications

(9 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The times to steady state for the inflows in Figure 7 are substantially less than those presented by Renault and Wallender (1996) for the cases of gated pipe and over bank siphons. In these two cases the times were determined not by hydraulic factors but by the time taken to open the gates along the gated pipe or to prime the siphons for each of the furrows.…”

Section: Fig 7 About Herementioning

confidence: 67%

“…Any change in the rate of inflow influences the trajectory of the irrigation advance and hence the irrigation performance for that furrow as indicated by the usual measures of application efficiency and uniformity (Renault and Wallender, 1996). Evaluation of the irrigation, using an inverse solution to predict the soil infiltration characteristic from the irrigation advance, is complicated by this inflow variation and error is introduced into those techniques that rely on an assumption of constant inflow (for example, Gillies et al 2007).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Head ditch hydraulics and the variability of inflows to irrigation furrows

Smith

Gillies

2009

Irrigation and Drainage

View full text Add to dashboard Cite

The spatial variability and temporal variation of furrow inflows have a major impact on the performance of furrow irrigation, as indicated by the usual measures of application efficiency and uniformity. They also cause difficulties in determining the soil infiltration characteristic through inverse solution techniques and in selecting preferred values for the operational variables of flow rate and time to cut-off to give maximum performance at the field scale.In this paper a steady spatially-varied flow analyses is performed to predict the steady water surface profiles in a typical head ditch and the subsequent spatial variability of the furrow inflows, for both pipe or siphon and sill or bank-less type water application systems. The resulting patterns were very similar to those seen in the spatially varied pipe flow in gated pipe, with depths and outflows increasing toward the downstream end of the channel. It is shown that it is feasible to design head ditches to minimise the variability in outflows. An unsteady analysis of the same head ditch illustrated the variation of outflows with time caused by the time taken to fill the channel. AbstraitLa variabilité spatiale et la variation temporelle des apports de sillon ont un impact important sur l'exécution de l'irrigation de sillon, en termes de mesures habituelles d'efficacité et d'uniformité d'application. Elles également occasionnent des difficultés en déterminant les techniques inverses traversantes caractéristiques de solution d'infiltration de sol et en choisissant des valeurs préférées pour les variables opérationnelles du débit et temps-à-coupent-au loin pour donner l'exécution optima à la balance de champ.Des analyses de flux Spatial-changées sont exécutées pour prévoir les profils réguliers de surface de l'eau dans un fossé typique de tête d'irrigation. La variabilité spatiale suivante des apports de sillon est analysée, des types de siphon-et-filon-couche ou de banque-moins de systèmes d'application de l'eau. Les modèles résultants étaient très semblables à ceux vus dans spatial-changé pipe-coulent dans la pipe à déchenchements périodiques, avec des profondeurs et des sorties augmentant vers l'extrémité descendant du canal. On voit qu'il est faisable pour concevoir les fossés principaux pour réduire au minimum la variabilité dans les sorties. Une analyse perturbée du même tête-fossé a illustré la variation des sorties avec du temps causé avant que pris pour remplir canal.

show abstract

Section: Fig 7 About Herementioning

confidence: 67%

Section: Introductionmentioning

confidence: 99%

Head ditch hydraulics and the variability of inflows to irrigation furrows

Smith

Gillies

2009

Irrigation and Drainage

View full text Add to dashboard Cite

show abstract

“…This suggests that accounting for the temporal variation in inflow should in many cases reduce the apparent variability between estimated infiltration rates for furrows in the same field. Renault and Wallender (1996) concluded that this would result in larger values of the Kostiakov k and lower values of a when assuming constant inflow.…”

Section: Inflow As a Source Of Variability In Spatial Estimates Of Inmentioning

confidence: 99%

“…Renault and Wallender (1996) found that initial variations in inflow rates often cause the resulting Kostiakov infiltration functions to have low a but high k. Experience with the INFILT optimisation of McClymont and Smith (1996) suggests that a seemingly small change in the inflow rate can have a considerable impact on the estimated infiltration function. However, inflow variation is often overlooked.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Accounting for temporal inflow variation in the inverse solution for infiltration in surface irrigation

2006

View full text Add to dashboard Cite

A simple modification of the volume balance equation of the IPARM model is presented to facilitate the use of variable inflow. Traditional approaches for estimating infiltration from advance and/or runoff have merely considered the constant or step inflow case. Whenever this assumption is violated, significant uncertainty is introduced into the estimated infiltration parameters. Evaluation of the procedure with a number of data sets has demonstrated significant improvements in the estimates of infiltration parameters. Furthermore, the technique has shown that a portion of the apparent variability in estimated soil intake rates between furrows in the same field is a consequence of the constant inflow assumption. Accounting for the variable inflow to estimate infiltration functions, both standardised the shape of the infiltration curve and reduced the magnitude of the variation between curves. The proposed technique remains restricted by limitations similar to that of other volume balance models but offers greater performance under typical inflow variations often experienced in practice.

show abstract

Infiltration parameters from surface irrigation advance and run-off data

Gillies

Smith

2005

Irrig Sci

View full text Add to dashboard Cite

A computer model was developed to employ runoff data in the calculation of the infiltration parameters of the modified Kostiakov equation. The model (IPARM) uses a simple volume balance approach to estimate the parameters from commonly collected field data. Several data sets have been used to verify the procedure. Infiltration parameters were calculated using both advance and runoff data combined and advance data alone. Simulations of each example using SIRMOD were compared to the measured data to identify the possible benefits of the procedure. The inclusion of runoff did not compromise the ability to reproduce the advance curve however the simulations are more capable of reproducing the measured runoff rates and volumes and therefore offer better estimations of the total volume applied to the soil (in one case a reduction in error of the total infiltration from 22% to 1%). This procedure will be of most benefit where the infiltration parameters are expected to represent soil hydraulic characteristics for times greater than the completion of the advance phase. Further analysis has shown that the infiltration parameters are more sensitive to runoff than the advance highlighting the requirement for accurate field measurement and a weighting factor between the advance and runoff errors.

show abstract

Initial-Inflow-Variation Impacts on Furrow Irrigation Evaluation

Cited by 11 publications

References 12 publications

Head ditch hydraulics and the variability of inflows to irrigation furrows

Head ditch hydraulics and the variability of inflows to irrigation furrows

Accounting for temporal inflow variation in the inverse solution for infiltration in surface irrigation

Infiltration parameters from surface irrigation advance and run-off data

Contact Info

Product

Resources

About