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Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective The weir-flume apparatus, consisting of a measuring flume and a measuring weir, is an innovative device for monitoring and controlling open channel flow. Installed across channels, it can measure water flow, elevates upstream water level, and enhances ecological connectivity in rivers in diverse geographical conditions. While measurement formulas and hydraulic characteristics have been experimentally investigated for small flow with shallow water depth, there is a lack of study for large flow. This paper aims to bridge this gap by studying the vertical and longitudinal velocity profiles as well as spatial distribution of flow field under high flow conditions. Method The analysis was based on numerical modelling. The FLOW-3D software was used to simulate hydraulic performance of a weir-flume device under 17 flow rates ranging from 10.13 to 200 L/s. From the simulated results we analyzed the impact of flow rate on water depth, Froude number (Fr), and velocities within both the in-groove flow and the weir flow. Result As the flow rate increased, the Fr and velocity in the central longitudinal section of the device initially increased and then tapered off. The flow in the upstream of the device remained stable, with Fr ranging from 0.1 to 0.3 and velocities varying between 0.08 and 0.5 m/s. Both Fr and velocity gradually increased with the increase in flow rate. After entering the device, Fr and flow velocity exhibited a significant surge. A wide range of thin water layers emerged in the downstream of the device, with the maximum Fr and velocities being 3 to 4.6 and 1.05 to 2.06 m/s, respectively. A subdued water jump was observed downstream of the in-groove flow, while the downstream of the weir showed a jet stream with Fr>1. Additionally, diffused water generated a rhomboid wave at the side bank. We derived a formula from the numerical simulations; its maximum relative error was 6.11% for flow rate below 100 L/s, beyond which the relative error gradually increased. Conclusion The numerical results obtained from FLOW-3D agreed well with the test data, validating the accuracy and consistency of the derived formula for analyzing measurement data from the weir-flume device. This work bridges a critical knowledge gap, enabling more precise assessment and control of open channel flow under various conditions. [ABSTRACT FROM AUTHOR]

[Background and Objective]Gravity-driven pipelines have low impact on geological environment, low leakage, simple construction and low operation cost. They have been widely used in irrigation and water supply projects. When the end valve is suddenly turn off under unpredicted circumstances, however, it could result in water hammer and pressure vibration in the pipelines, threating safe operation of the system. Considering water hammer is more likely to occur in long-distance gravity flow pipeline in hilly areas, this paper explore efficacy of different methods to ameliorate the damaging effect of water hammer on gravity flow pipeline in hilly areas.[Method]The study is based on the gravity pipeline project in Qianyang County, Shaanxi province. Numerical simulation combined with inclined straight pipes and fitted equivalent short straight pipe is used to simulate the protective effect of setting inlet and exhaust valve in each hump section and an overpressure relief valve in the front of the end control valve section. We analyzed the simulation results to determine the effect of these methods in alleviating water hammer at specific locations in the pipelines.[Result]Without the water hammer protection measure, when the control valve at the end of the pipeline is turn off quickly, there is no noticeable negative pressure along the pipeline; the maximum negative pressure head reaches - 20.06 m, and the maximum positive pressure at the section of the control valve at the end of the pipeline reaches 87.58 m. Installation of the water hammer protection measures eliminates the occurrence of negative pressure in the pipeline and reduces the maximum positive pressure head in the pipeline to 70.88 m, which is lower than the critical pressure for occurrence of water hammer in the pipelines. [Conclusion]For the gravity-driven water transmission pipeline in hilly areas, combination of inlet and exhaust valve and an over-pressure relief valve can effectively alleviate the occurrence of water hammer and ensure that the pressure in the pipeline is less than the critical pressure required in the design of the pipelines. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Objective] Water flow and solute transport in soil is important not only for plant acquisition of resources from soil but also for soil and water environment. In terrestrial ecosystems, they are impacted by numerous factors. The objective of this paper is to investigate the effects of drip irrigation amount on spatiotemporal change in water and nitrogen in Hetao Irrigation District, Inner Mongolia. [Method] A field experiment was conducted to measure the movement of water, nitrate and ammonium in soils, with the irrigation amount controlled at 6 mm (D1) or 60 mm (D2). The measured data was used to calibrate the HYDRUS-2D model, and the calibrated model was then used to elucidate how increasing the irrigation amount to 120 mm would affect water and nitrogen movement. [Result] Irrigation increased soil water content in all growth stages. Following irrigation and fertilization, ammonium and nitrate contents both increased rapidly and then decreased. On average, ammonium and nitrate in the 0~10 cm soil layer decreased by 60.0%~62.0% and 40.0%~46.7%, respectively, after the D1 and D2 irrigations, with the decreasing rate varying with growing stage. Compared to D2, D1 increased soil water content at jointing, heading and filling stage by 5.9%, 8.0% and 6.7%, respectively. Soil ammonium and nitrate both decreased along the soil depth. Nitrate accumulation decreased gradually when the crop grew from jointing stage to filling stage. The simulated soil water content and nitrogen agreed well with the measured data. [Conclusion] Experimental data and simulated results showed that irrigating the maize by 120 mm of water can effectively reduce accumulation of nitrate in the 0~60 cm soil layer, and that increasing irrigation frequencies can further curtail nitration accumulation in the 60~100 cm soil layer. These results provide guidance for improving irrigation and fertigation for maize production in Hetao Irrigation District. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

(Objective) Some rivers have islands. Their soil composition and geometrical shape influence water flow and sediment transport in the rivers. The purpose of this paper is to study the impact of flow rate and flowing duration on sediment erosion and hydrodynamic flow in a bended river. (Method) The study is based on two-dimensional average shallow water flow and sediment transport over riverbeds. Both water flow and sediment transport are solved using the MIKE 21. The model is applied to the section of Yellow River at Yongfeng Ferry in Ningxia province, where there are several small islands.(Result) When water flows for 3 hours at rate of 1 545 m³/s, sediment erosion reduces water velocity by 0.06~0.27 m/s and water depth by 0.02~0.32 m, compared with the results calculated without considering sediment erosion. Continuous erosion tends to stabilize water depth and flow rate. The deepest erosion depth is 0.16 m after water flows for 3 hours at rate 1 545 m³/s, and this increases to 0.24 m after the flow is increased to 6 hours at the same rate; their associated maximum deposition depth is 0.12 m and 0.23 m respectively. With the increase in flow rate and flow duration, the riverbed stabilizes, though erosion depth and deposition thickness continue to change. (Conclusion ) Sediment erosion increases the stability of hydrodynamic flow in the river, and the riverbed morphology does not change after flow rate exceeds a critical rate. These simulated results are consistent and can be used to help improve river management. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

(Background) The Yellow River Irrigation Area built in Ningxia of China comprises a number of irrigation canals that could be damaged by heaves induced by frosts in winter, destabilizing canal slopes and resulting in water leakage. Developing anti-frost technologies to mitigate the heave damage is hence critical to safeguarding the operation of the canals. Soil freezing in the canals is a hydrothermal process involving phase change; it is impacted by topographic, geological and hydrological factors. Understanding temperature distribution in the peripheral soil of the canal can help mitigate heave formation induced by freezing-thawing cycles. (Objective) The objective of this paper is to numerically simulate temperature distribution in the soil surrounding the U-shaped concrete canals under different conditions in attempts to provide guidance to help anti-heave design in constructing canals in semi- permafrost regions like Ningxia. (Method) The study was based on data measured from U-shaped concrete canals in Shahu Village, Shaogang Town, Qingtongxia City. We first used the AKIMA interpolation to calculate the temperature distribution in the soil around the canals, and then numerically simulated thermal flow and temperature distribution in the soils using the ANSYS software. (Result) Since the temperature in the shady slope is much lower than that in the sunny side, frost heave occurred early in the former and the frozen soil in it also developed much deeper. The temperature gradient underneath the lining a different locations around the canal was roughly the same, and in general, the temperature gradient was the highest in regions proximal to the soil surface and decreased with the soil depth. The average temperature gradient in the shady slope was higher than that on the sunny side, and the temperature gradient in the canal base tends to zero as the soil depth increased. The temperature varies more dramatically in the 20 cm of soil underneath the lining, and in soils 50~100 cm from the lining, the temperature gradient was almost zero. Comparison with observed data showed that the AKIMA interpolation combined with the ANSYS software can accurately simulated the temperature distribution. ( Conclusion) Results obtained from AKIMA and ANSYS were consistent with the measured data and they can be used to help anti-frost design in building U-shaped concrete canals in areas with freezing-thawing cycles in Ningxia and beyond. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)