The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Yinong Li - One of the best experts on this subject based on the ideXlab platform.
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A Non-Uniform Broadcast Fertilization Method and Its Performance Analysis under Basin Irrigation
Water, 2020Co-Authors: Kai Zhang, Shaohui Zhang, Yinong Li, Di XuAbstract:The broadcast fertilization method is widely used under Basin Irrigation in China. A reasonable broadcast fertilization method can effectively improve application performance of fertilization and reduce pollution from non-point agricultural sources. In this study, firstly, a non-uniform broadcast fertilization method and a non-uniform application coefficient were proposed. The value of non-uniform application coefficient is defined in this paper. It represents the ratio of the difference between the maximum and the average fertilization amount of fertilizer applied on the Basin surface to the average fertilization amount of fertilizer applied on the Basin surface. Secondly, field experiments were conducted to study the movement characteristics of fertilizer under non-uniform broadcast fertilization for Basin Irrigation. Field experiment results showed that under the condition of Basin Irrigation, the non-uniform broadcast fertilization method could weaken the non-uniform distribution of fertilizer due to erosion and transport capacity of solid fertilizer by Irrigation water flow, which could significantly improve the uniformity of soil solute content. Thirdly, the solute transport model for broadcast fertilization was corroborated by the field experiment results. The variation rule of fertilization performance with non-uniform application coefficient under different Basin length and inflow rate was achieved by simulation. The simulation results showed that fertilization uniformity and fertilization storage efficiency increased first and then decreased with the increase of non-uniform application coefficient. In order to be practically applicable, suitable Irrigation programs of non-uniform application coefficient under different Basin length and inflow rate conditions were proposed by numerical simulation.
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Coupled impact of spatial variability of infiltration and microtopography on Basin Irrigation performances
Irrigation Science, 2017Co-Authors: Di Xu, Yinong Li, Shaohui ZhangAbstract:Soil surface elevation and infiltration are two key variables that affect Basin Irrigation performances. A number of sets of spatially variable surface elevation and infiltration parameters were generated using stochastic modeling, and a 2D Basin Irrigation model was used to simulate Irrigation for the generated sets. Strip, narrow, and wide Basins, with different slope, land leveling precision, infiltration variation and inflow rate were analyzed. The coupled influence of spatial variation of microtopography and infiltration on Irrigation performance, relationship between the influence degrees and degrees of spatial variance, and other Irrigation factors were discussed. Results show that the Basin Irrigation performance decreased with increased spatial variability of microtopography and infiltration. The effect of the spatial variability of microtopography became more obvious when S d (land leveling precision) was more than 1 cm. Smaller spatial variability of infiltration resulted in a stronger influence degree of microtopography on Irrigation performance, and increasing the inflow can weaken this influence. The spatial variability of infiltration mainly affected the Irrigation uniformity CU, and the effect on the infiltrated depth when advance was completed (Z adv) was very small. The influence of infiltration variation on Irrigation performances increased with Enhanced land leveling precision, especially for zero-leveled Basins. For such Basins, the influence of infiltration variation on Irrigation performance should be paid more attention in the design and management of Irrigation systems.
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Two-dimensional zero-inertia model of surface water flow for Basin Irrigation based on the standard scalar parabolic type
Irrigation Science, 2014Co-Authors: Shaohui Zhang, Di Xu, Yinong LiAbstract:The two-dimensional zero-inertia equations for Basin Irrigation were formulated as a standard scalar diffusion equation subject to neumann boundary condi- tions. The formulation can handle anisotropic variations in hydraulic resistance. a numerical solution was developed using finite-volume method on unstructured triangular cells. The simulation performance of the constructed model was validated based on typical experimental data. The com- plete hydrodynamic model of Basin Irrigation was selected as the comparative model. The validated results show that the constructed model can successfully simulate the Basin surface water flow when the Basin surface microtopog- raphy condition is relatively smooth. Similar results were found in terms of both the water quantity conservation and
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Dimensional Splitting Finite-Volume Method for Two-Dimensional Surface Water Flow Model in Basin Irrigation
Journal of Irrigation and Drainage Engineering-asce, 2014Co-Authors: Shaohui Zhang, Di Xu, Yinong LiAbstract:AbstractThe concept of major direction correction is proposed, which includes complete major direction correction, major direction correction without roughness, and no major direction correction, based on the dimensional splitting expression of a two-dimensional surface water flow model in surface Irrigation. The dimensional splitting finite-volume methods for Basin Irrigation were developed based on the major direction correction and existing dimensional splitting numerical methods, in addition to the scalar dissipation finite-volume method. The simulation performance of two-dimensional surface water flow models of Basin Irrigation constructed by the dimensional splitting finite-volume methods were comparatively validated and analyzed based on Basin Irrigation experiments. The results show that the models based on the Strang dimensional splitting methods with complete major direction correction and major direction correction without roughness have similar simulation accuracy and convergence rates with th...
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two dimensional surface water flow simulation of Basin Irrigation with anisotropic roughness
Irrigation Science, 2014Co-Authors: Shaohui Zhang, Di Xu, Yinong LiAbstract:Simulating Basin surface water flow with anisotropic roughness has practical significance. Based on the complete hydrodynamic model, a two-dimensional surface water flow model of Basin Irrigation with anisotropic roughness was developed in this study by constructing an anisotropic roughness model in the source terms of the governing equation. Then, the simulation performance of the proposed model was analyzed and compared based on typical experiments of Basin Irrigation. The results show that with Basin surface anisotropic roughness, the proposed model can successfully simulate water flow in Basin Irrigation, and exhibits better simulation performance than the model with isotropic roughness. Three Basin geometries and two kinds of inflow geometries were selected for the application of the proposed model. Applied results show that the anisotropic roughness can improve Irrigation performance. When the Basin width becomes narrow, the physical effect of the rotation angle in the anisotropic roughness model weakens, even becomes smooth. The two-dimensional surface water flow model of Basin Irrigation with anisotropic roughness provides a good numerical simulation tool for designing and evaluating the performance of Basin Irrigation system.
Shaohui Zhang - One of the best experts on this subject based on the ideXlab platform.
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A Non-Uniform Broadcast Fertilization Method and Its Performance Analysis under Basin Irrigation
Water, 2020Co-Authors: Kai Zhang, Shaohui Zhang, Yinong Li, Di XuAbstract:The broadcast fertilization method is widely used under Basin Irrigation in China. A reasonable broadcast fertilization method can effectively improve application performance of fertilization and reduce pollution from non-point agricultural sources. In this study, firstly, a non-uniform broadcast fertilization method and a non-uniform application coefficient were proposed. The value of non-uniform application coefficient is defined in this paper. It represents the ratio of the difference between the maximum and the average fertilization amount of fertilizer applied on the Basin surface to the average fertilization amount of fertilizer applied on the Basin surface. Secondly, field experiments were conducted to study the movement characteristics of fertilizer under non-uniform broadcast fertilization for Basin Irrigation. Field experiment results showed that under the condition of Basin Irrigation, the non-uniform broadcast fertilization method could weaken the non-uniform distribution of fertilizer due to erosion and transport capacity of solid fertilizer by Irrigation water flow, which could significantly improve the uniformity of soil solute content. Thirdly, the solute transport model for broadcast fertilization was corroborated by the field experiment results. The variation rule of fertilization performance with non-uniform application coefficient under different Basin length and inflow rate was achieved by simulation. The simulation results showed that fertilization uniformity and fertilization storage efficiency increased first and then decreased with the increase of non-uniform application coefficient. In order to be practically applicable, suitable Irrigation programs of non-uniform application coefficient under different Basin length and inflow rate conditions were proposed by numerical simulation.
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Coupled impact of spatial variability of infiltration and microtopography on Basin Irrigation performances
Irrigation Science, 2017Co-Authors: Di Xu, Yinong Li, Shaohui ZhangAbstract:Soil surface elevation and infiltration are two key variables that affect Basin Irrigation performances. A number of sets of spatially variable surface elevation and infiltration parameters were generated using stochastic modeling, and a 2D Basin Irrigation model was used to simulate Irrigation for the generated sets. Strip, narrow, and wide Basins, with different slope, land leveling precision, infiltration variation and inflow rate were analyzed. The coupled influence of spatial variation of microtopography and infiltration on Irrigation performance, relationship between the influence degrees and degrees of spatial variance, and other Irrigation factors were discussed. Results show that the Basin Irrigation performance decreased with increased spatial variability of microtopography and infiltration. The effect of the spatial variability of microtopography became more obvious when S d (land leveling precision) was more than 1 cm. Smaller spatial variability of infiltration resulted in a stronger influence degree of microtopography on Irrigation performance, and increasing the inflow can weaken this influence. The spatial variability of infiltration mainly affected the Irrigation uniformity CU, and the effect on the infiltrated depth when advance was completed (Z adv) was very small. The influence of infiltration variation on Irrigation performances increased with Enhanced land leveling precision, especially for zero-leveled Basins. For such Basins, the influence of infiltration variation on Irrigation performance should be paid more attention in the design and management of Irrigation systems.
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Efficient Simulation of Surface Water Flow in 2D Basin Irrigation Using Zero-Inertia Equations
Journal of Irrigation and Drainage Engineering-asce, 2016Co-Authors: Shaohui Zhang, Hongjing YuAbstract:AbstractZero-inertia equations are more easily numerically solved than complete hydrodynamic equations. Thus, the zero-inertia equations were applied to describe the surface water flows in 2D Basin Irrigation. Then, finite-volume and finite-difference approaches in the spatial cell and cell interface spatially were applied to discretize the continuous and momentum components of zero-inertia equations, respectively. Meanwhile, a dual time-stepping approach was implicitly implemented to achieve unconditional stability. The Gauss–Seidel iterative method was used to solve the space–time discretized expressions of the zero-inertia equations, and an efficient numerical model for 2D Basin Irrigation was developed. Three field experiments were conducted to validate the developed model. The validated results show that the developed model presents good agreement between the simulated and observed data, and achieves more mass conservation than the existing model. Its high efficiency is suitable for practical enginee...
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Two-dimensional zero-inertia model of surface water flow for Basin Irrigation based on the standard scalar parabolic type
Irrigation Science, 2014Co-Authors: Shaohui Zhang, Di Xu, Yinong LiAbstract:The two-dimensional zero-inertia equations for Basin Irrigation were formulated as a standard scalar diffusion equation subject to neumann boundary condi- tions. The formulation can handle anisotropic variations in hydraulic resistance. a numerical solution was developed using finite-volume method on unstructured triangular cells. The simulation performance of the constructed model was validated based on typical experimental data. The com- plete hydrodynamic model of Basin Irrigation was selected as the comparative model. The validated results show that the constructed model can successfully simulate the Basin surface water flow when the Basin surface microtopog- raphy condition is relatively smooth. Similar results were found in terms of both the water quantity conservation and
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Dimensional Splitting Finite-Volume Method for Two-Dimensional Surface Water Flow Model in Basin Irrigation
Journal of Irrigation and Drainage Engineering-asce, 2014Co-Authors: Shaohui Zhang, Di Xu, Yinong LiAbstract:AbstractThe concept of major direction correction is proposed, which includes complete major direction correction, major direction correction without roughness, and no major direction correction, based on the dimensional splitting expression of a two-dimensional surface water flow model in surface Irrigation. The dimensional splitting finite-volume methods for Basin Irrigation were developed based on the major direction correction and existing dimensional splitting numerical methods, in addition to the scalar dissipation finite-volume method. The simulation performance of two-dimensional surface water flow models of Basin Irrigation constructed by the dimensional splitting finite-volume methods were comparatively validated and analyzed based on Basin Irrigation experiments. The results show that the models based on the Strang dimensional splitting methods with complete major direction correction and major direction correction without roughness have similar simulation accuracy and convergence rates with th...
Di Xu - One of the best experts on this subject based on the ideXlab platform.
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A Non-Uniform Broadcast Fertilization Method and Its Performance Analysis under Basin Irrigation
Water, 2020Co-Authors: Kai Zhang, Shaohui Zhang, Yinong Li, Di XuAbstract:The broadcast fertilization method is widely used under Basin Irrigation in China. A reasonable broadcast fertilization method can effectively improve application performance of fertilization and reduce pollution from non-point agricultural sources. In this study, firstly, a non-uniform broadcast fertilization method and a non-uniform application coefficient were proposed. The value of non-uniform application coefficient is defined in this paper. It represents the ratio of the difference between the maximum and the average fertilization amount of fertilizer applied on the Basin surface to the average fertilization amount of fertilizer applied on the Basin surface. Secondly, field experiments were conducted to study the movement characteristics of fertilizer under non-uniform broadcast fertilization for Basin Irrigation. Field experiment results showed that under the condition of Basin Irrigation, the non-uniform broadcast fertilization method could weaken the non-uniform distribution of fertilizer due to erosion and transport capacity of solid fertilizer by Irrigation water flow, which could significantly improve the uniformity of soil solute content. Thirdly, the solute transport model for broadcast fertilization was corroborated by the field experiment results. The variation rule of fertilization performance with non-uniform application coefficient under different Basin length and inflow rate was achieved by simulation. The simulation results showed that fertilization uniformity and fertilization storage efficiency increased first and then decreased with the increase of non-uniform application coefficient. In order to be practically applicable, suitable Irrigation programs of non-uniform application coefficient under different Basin length and inflow rate conditions were proposed by numerical simulation.
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Coupled impact of spatial variability of infiltration and microtopography on Basin Irrigation performances
Irrigation Science, 2017Co-Authors: Di Xu, Yinong Li, Shaohui ZhangAbstract:Soil surface elevation and infiltration are two key variables that affect Basin Irrigation performances. A number of sets of spatially variable surface elevation and infiltration parameters were generated using stochastic modeling, and a 2D Basin Irrigation model was used to simulate Irrigation for the generated sets. Strip, narrow, and wide Basins, with different slope, land leveling precision, infiltration variation and inflow rate were analyzed. The coupled influence of spatial variation of microtopography and infiltration on Irrigation performance, relationship between the influence degrees and degrees of spatial variance, and other Irrigation factors were discussed. Results show that the Basin Irrigation performance decreased with increased spatial variability of microtopography and infiltration. The effect of the spatial variability of microtopography became more obvious when S d (land leveling precision) was more than 1 cm. Smaller spatial variability of infiltration resulted in a stronger influence degree of microtopography on Irrigation performance, and increasing the inflow can weaken this influence. The spatial variability of infiltration mainly affected the Irrigation uniformity CU, and the effect on the infiltrated depth when advance was completed (Z adv) was very small. The influence of infiltration variation on Irrigation performances increased with Enhanced land leveling precision, especially for zero-leveled Basins. For such Basins, the influence of infiltration variation on Irrigation performance should be paid more attention in the design and management of Irrigation systems.
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Two-dimensional zero-inertia model of surface water flow for Basin Irrigation based on the standard scalar parabolic type
Irrigation Science, 2014Co-Authors: Shaohui Zhang, Di Xu, Yinong LiAbstract:The two-dimensional zero-inertia equations for Basin Irrigation were formulated as a standard scalar diffusion equation subject to neumann boundary condi- tions. The formulation can handle anisotropic variations in hydraulic resistance. a numerical solution was developed using finite-volume method on unstructured triangular cells. The simulation performance of the constructed model was validated based on typical experimental data. The com- plete hydrodynamic model of Basin Irrigation was selected as the comparative model. The validated results show that the constructed model can successfully simulate the Basin surface water flow when the Basin surface microtopog- raphy condition is relatively smooth. Similar results were found in terms of both the water quantity conservation and
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Dimensional Splitting Finite-Volume Method for Two-Dimensional Surface Water Flow Model in Basin Irrigation
Journal of Irrigation and Drainage Engineering-asce, 2014Co-Authors: Shaohui Zhang, Di Xu, Yinong LiAbstract:AbstractThe concept of major direction correction is proposed, which includes complete major direction correction, major direction correction without roughness, and no major direction correction, based on the dimensional splitting expression of a two-dimensional surface water flow model in surface Irrigation. The dimensional splitting finite-volume methods for Basin Irrigation were developed based on the major direction correction and existing dimensional splitting numerical methods, in addition to the scalar dissipation finite-volume method. The simulation performance of two-dimensional surface water flow models of Basin Irrigation constructed by the dimensional splitting finite-volume methods were comparatively validated and analyzed based on Basin Irrigation experiments. The results show that the models based on the Strang dimensional splitting methods with complete major direction correction and major direction correction without roughness have similar simulation accuracy and convergence rates with th...
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two dimensional surface water flow simulation of Basin Irrigation with anisotropic roughness
Irrigation Science, 2014Co-Authors: Shaohui Zhang, Di Xu, Yinong LiAbstract:Simulating Basin surface water flow with anisotropic roughness has practical significance. Based on the complete hydrodynamic model, a two-dimensional surface water flow model of Basin Irrigation with anisotropic roughness was developed in this study by constructing an anisotropic roughness model in the source terms of the governing equation. Then, the simulation performance of the proposed model was analyzed and compared based on typical experiments of Basin Irrigation. The results show that with Basin surface anisotropic roughness, the proposed model can successfully simulate water flow in Basin Irrigation, and exhibits better simulation performance than the model with isotropic roughness. Three Basin geometries and two kinds of inflow geometries were selected for the application of the proposed model. Applied results show that the anisotropic roughness can improve Irrigation performance. When the Basin width becomes narrow, the physical effect of the rotation angle in the anisotropic roughness model weakens, even becomes smooth. The two-dimensional surface water flow model of Basin Irrigation with anisotropic roughness provides a good numerical simulation tool for designing and evaluating the performance of Basin Irrigation system.
Luis S. Pereira - One of the best experts on this subject based on the ideXlab platform.
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Improvement Of Basin Irrigation For Water Savings And Salinity Control In The Yellow River Basin, China
2002 Chicago IL July 28-31 2002, 2020Co-Authors: M. S. Fabião, A. A. Campos, Luis S. Pereira, J. M. Gonçalves, Y. N. Li, B. DongAbstract:A study focusing the improvement of the Basin Irrigation is performed in the Huinong Irrigation District, in the upper reaches of the Yellow River Basin, Ningxia Province, and in the Bojili Irrigation District, in the lower reaches of the Basin, Shandong Province. Studies include the field evaluation of current Basin Irrigation practices and the use of the simulation models SRFR and SIRMOD to simulate improved designs and practices. The target depths are generated by the Irrigation scheduling simulation model ISAREG. For Huinong, achieving a control of present excess Irrigation water applied and the induced water table rise and salinity requires that the Basin water advance would be completed in a much smaller time than at present. Therefore, improvements on field sizes, land leveling, infiltration conditions and inflow discharges available are identified aiming at water savings and controlling waterlogging and salinity. At Bojili, the main problems relate to excessive field lengths and relatively poor land leveling, which induce very slow advance times and therefore, either excess water application or the under-Irrigation of the downstream part of the field. Solutions therefore include improved land leveling, larger inflow discharges and reduction of field lengths. The paper summarizes the approaches used to calibrate the simulation models from field observations, an analysis of present conditions and performances, and a discussion on the proposed issues for both areas.
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Basin Irrigation Design with Multi-Criteria Analysis Focusing on Water Saving and Economic Returns: Application to Wheat in Hetao, Yellow River Basin
Water, 2018Co-Authors: Qingfeng Miao, J. M. Gonçalves, Luis S. PereiraAbstract:The sustainability of the Hetao Irrigation System, located in the water scarce upper Yellow River Basin, is a priority considering the need for water saving, increased water productivity, and higher farmers’ incomes. The upgrading of Basin Irrigation, the main Irrigation method, is essential and includes the adoption of precise land levelling, cut-off management, improved water distribution uniformity, and adequate Irrigation scheduling. With this objective, the current study focuses on upgrading wheat Basin Irrigation through improved design using a decision support system (DSS) model, which considers land parcels characteristics, crop Irrigation scheduling, soil infiltration, hydraulic simulation, and environmental and economic impacts. Its use includes outlining water saving scenarios and ranking alternative designs through multi-criteria analysis considering the priorities of stakeholders. The best alternatives concern flat level Basins with a 100 and 200 m length and inflow rates between 2 and 4 L s−1 m−1. The total Irrigation cost of designed projects, including the cost of the autumn Irrigation, varies between 2400 and 3300 Yuan ha−1; the major cost component is land levelling, corresponding to 33–46% of total Irrigation costs. The economic land productivity is about 18,000 Yuan ha−1. The DSS modelling defined guidelines to be applied by an extension service aimed at implementing better performing Irrigation practices, and encouraged a good interaction between farmers and the Water Users Association, thus making easier the implementation of appropriate Irrigation management programs.
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assessing Basin Irrigation and scheduling strategies for saving Irrigation water and controlling salinity in the upper yellow river Basin china
Agricultural Water Management, 2007Co-Authors: Luis S. Pereira, J. M. Gonçalves, B. Dong, S X FangAbstract:Water saving in Irrigation is a key concern in the Yellow River Basin. Excessive water diversions for Irrigation waste water and produce waterlogging problems during the crop season and soil salinization in low lands. Supply control and inadequate functionality of the drainage system were identified as main factors for poor water management at farm level. Their improvement condition the adoption of water saving and salinity control practices. Focusing on the farm scale, studies to assess the potential for water savings included: (a) field evaluation of current Basin Irrigation practices and further use of the simulation models SRFR and SIRMOD to generate alternative improvements for the surface Irrigation systems and (b) the use of the ISAREG model to simulate the present and improved Irrigation scheduling alternatives taking into consideration salinity control. Models were used interactively to define alternatives for the Irrigation systems and scheduling that would minimize percolation and produce water savings. Foreseen improvements refer to Basin inflow discharges, land leveling and Irrigation scheduling that could result in water savings of 33% relative to actual demand. These improvements would also reduce percolation and maintain water table depths below 1 m thereby reducing soil salinization.
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Water Saving in the Yellow River Basin, China. 2. Assessing the Potential for Improving Basin Irrigation
Agricultural Engineering International: The CIGR Journal, 2003Co-Authors: M. S. Fabião, A. A. Campos, Luis S. Pereira, Y. N. Li, J. Gonclaves, B. DongAbstract:A study focusing the improvement of the Basin Irrigation is performed in the Huinong Irrigation District (HID), in the upper reaches of the Yellow River Basin, Ningxia Province, and in the Bojili Irrigation District (BID), in the lower reaches of the Basin, Shandong Province. Studies include the field evaluation of current Basin Irrigation practices and the use of the simulation models SRFR and SIRMOD to search for improved designs and practices. The target application depths are generated by the Irrigation scheduling simulation model ISAREG. For HID, achieving a control of present excess Irrigation water applied and the induced water table rise and salinity requires that the Basin water advance would be completed in a much shorter time than at present. Therefore, improvements in field sizes, land leveling, infiltration conditions and inflow rates are identified aiming at water savings and controlling waterlogging and salinity. At BID, the main problems relate to excessive field lengths and relatively poor land leveling, which induce very slow advance times, which are associated with excess water application or under-Irrigation of the downstream part of the field. Solutions therefore include improved land leveling, larger inflow discharges and reduction of field lengths. The paper summarizes the approaches used to calibrate the simulation models from field observations, an analysis of present conditions and performances, and a discussion on the proposed issues for both areas.
S X Fang - One of the best experts on this subject based on the ideXlab platform.
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assessing Basin Irrigation and scheduling strategies for saving Irrigation water and controlling salinity in the upper yellow river Basin china
Agricultural Water Management, 2007Co-Authors: Luis S. Pereira, J. M. Gonçalves, B. Dong, S X FangAbstract:Water saving in Irrigation is a key concern in the Yellow River Basin. Excessive water diversions for Irrigation waste water and produce waterlogging problems during the crop season and soil salinization in low lands. Supply control and inadequate functionality of the drainage system were identified as main factors for poor water management at farm level. Their improvement condition the adoption of water saving and salinity control practices. Focusing on the farm scale, studies to assess the potential for water savings included: (a) field evaluation of current Basin Irrigation practices and further use of the simulation models SRFR and SIRMOD to generate alternative improvements for the surface Irrigation systems and (b) the use of the ISAREG model to simulate the present and improved Irrigation scheduling alternatives taking into consideration salinity control. Models were used interactively to define alternatives for the Irrigation systems and scheduling that would minimize percolation and produce water savings. Foreseen improvements refer to Basin inflow discharges, land leveling and Irrigation scheduling that could result in water savings of 33% relative to actual demand. These improvements would also reduce percolation and maintain water table depths below 1 m thereby reducing soil salinization.
