scholarly journals The Waterlogging Process Model in the Paddy Fields of Flat Irrigation Districts

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2668
Author(s):  
Yujiang Xiong ◽  
Zhenyang Liu ◽  
Fengli Liu ◽  
Niannian Yuan ◽  
Haolong Fu

Flat, low-lying agricultural areas such as irrigation districts in southern China have been increasingly vulnerable to flood inundation disasters because of the increased runoff associated with urbanization and climate change. In this study, we developed a waterlogging process simulation model comprising two parts: runoff generation module and runoff confluence module. An improved tank model and hydrodynamic model based on Saint–Venant equations were adopted in the runoff generation and confluence module, respectively. The results show that the model’s relative error and root mean square error are 2.1% and 0.17 mm/h, and the Nash coefficient of the model is 0.91. The relative error of river level simulation was within 5%, and the Nash coefficient was higher than 0.9. The proposed waterlogging simulation model could be a valuable tool for describing the process of waterlogging generation, accumulation, and confluence in the studied irrigation district or other regions with similar climatic conditions.

2021 ◽  
Author(s):  
Hang Chen ◽  
Zailin Huo ◽  
Lu Zhang ◽  
Jing Cui ◽  
Yingying Shen ◽  
...  

Abstract. Budyko's framework has been widely used to study basin-scale water balance. In this study, we focus on the extended application of Fu's equation (one formulation of the Budyko-type curves) to 371 large irrigation districts in China over a period of 2010–2017. Water balance method was used to estimate actual evapotranspiration (ET) in the irrigated areas. Considering the contribution of shallow groundwater to ET, the water availability in the Budyko framework defined as equivalent precipitation (Pe) for irrigation areas is the sum of irrigation water (I), precipitation (P) and groundwater evaporation (ETgw). Results showed that the relationships between evapotranspiration (ET), water availability (Pe) and energy supply (ET0) can be accurately described by the Budyko's curves. The Fu's equation performed better in humid and semi-humid regions than arid and semi-arid regions. The comparison between δET/δPe and δET/δET0 confirmed the relative effect of water availability and energy supply on ET according to the variation of climatic conditions. The optimal values of Budyko parameter ω for each irrigation district was obtained with multi-annual data using least square method. Normalized Difference Vegetation Index (NDVI) and soil property (denoted by the proportion of clay and sand) were selected to develop empirical equation for parameter ω using multiple linear regression analysis method. This study showed that the Budyko framework can be extended to irrigation areas and provide useful information on evapotranspiration to assist in water management in irrigation areas.


2012 ◽  
Vol 43 (1-2) ◽  
pp. 54-63 ◽  
Author(s):  
Baohong Lu ◽  
Huanghe Gu ◽  
Ziyin Xie ◽  
Jiufu Liu ◽  
Lejun Ma ◽  
...  

Stochastic simulation is widely applied for estimating the design flood of various hydrosystems. The design flood at a reservoir site should consider the impact of upstream reservoirs, along with any development of hydropower. This paper investigates and applies a stochastic simulation approach for determining the design flood of a complex cascade of reservoirs in the Longtan watershed, southern China. The magnitude of the design flood when the impact of the upstream reservoirs is considered is less than that without considering them. In particular, the stochastic simulation model takes into account both systematic and historical flood records. As the reliability of the frequency analysis increases with more representative samples, it is desirable to incorporate historical flood records, if available, into the stochastic simulation model. This study shows that the design values from the stochastic simulation method with historical flood records are higher than those without historical flood records. The paper demonstrates the advantages of adopting a stochastic flow simulation approach to address design-flood-related issues for a complex cascade reservoir system.


Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 692
Author(s):  
Boyu Mi ◽  
Haorui Chen ◽  
Shaoli Wang ◽  
Yinlong Jin ◽  
Jiangdong Jia ◽  
...  

The water movement research in irrigation districts is important for food production. Many hydrological models have been proposed to simulate the water movement on the regional scale, yet few of them have comprehensively considered processes in the irrigation districts. A novel physically based distributed model, the Irrigation Districts Model (IDM), was constructed in this study to address this problem. The model combined the 1D canal and ditch flow, the 1D soil water movement, the 2D groundwater movement, and the water interactions among these processes. It was calibrated and verified with two-year experimental data from Shahaoqu Sub-Irrigation Area in Hetao Irrigation District. The overall water balance error is 2.9% and 1.6% for the two years, respectively. The Nash–Sutcliffe efficiency coefficient (NSE) of water table depth and soil water content is 0.72 and 0.64 in the calibration year and 0.68 and 0.64 in the verification year. The results show good correspondence between the simulation and observation. It is practicable to apply the model in water movement research of irrigation districts.


2021 ◽  
Author(s):  
Qiufen Zhang ◽  
Xizhi Lv ◽  
Rongxin Chen ◽  
Yongxin Ni ◽  
Li Ma

<p>The slope runoff caused by rainstorm is the main cause of serious soil and water loss in the loess hilly area, the grassland vegetation has a good inhibitory effect on the slope runoff, it is of great significance to reveal the role of grassland vegetation in the process of runoff generation and control mechanism for controlling soil erosion in this area. In this study, typical grassland slopes in hilly and gully regions of the loess plateau were taken as research objects. Through artificial rainfall in the field, the response rules of slope rainfall-runoff process to different grass coverage were explored. The results show that: (1) The time for the slope flow to stabilize is prolonged with the increase of vegetation coverage, and shortened with the increase of rainfall intensity; (2) At 60 mm·h <sup>−1</sup> rainfall intensity, the threshold of grassland vegetation coverage is 75.38%; at 90 mm·h<sup> −1</sup> rainfall intensity, the threshold of grassland vegetation coverage is 90.54%; at 120 mm·h <sup>−1</sup> rainfall intensity, the impact of grassland vegetation coverage on runoff is not significant; (3) the Reynolds number and Froude number of slope flow are 40.07‒695.22 and 0.33‒1.56 respectively, the drag coefficient is 1.42‒43.53. Under conditions of heavy rainfall, the ability of grassland to regulate slope runoff is limited. If only turf protection is considered, about 90% of grassland coverage can effectively cope with soil erosion caused by climatic conditions in loess hilly and gully regions. Therefore, in loess hilly areas where heavy rains frequently occur, grassland's protective effect on soil erosion is obviously insufficient, and investment in vegetation measures for trees and shrubs should be strengthened.</p>


2021 ◽  
Author(s):  
Xinjian Guan ◽  
Qiongying Du ◽  
Wenge Zhang ◽  
Baoyong Wang

Abstract Establishing and perfecting the water rights system is an important way to alleviate the shortage of water resources and realize the optimal allocation of water resources. Agriculture is an important user of water in various water-consumption industries, the confirmation of water rights in irrigation districts to farmers is the inevitable requirement for implementing fine irrigation in agricultural production. In this paper, a double-level water rights allocation model of national canals – farmer households in irrigation district is established. It takes into account the current water consumption of the canal system, the future water-saving potential and the constraint of total amount control at the canal level. It takes into account the asymmetric information of farmer households’ population and irrigation area at the farmer household level. Furthermore, the Gini coefficient method is used to construct the water rights allocation model among farmer households based on the principle of fairness. Finally, Wulanbuhe Irrigation Area in the Hetao Irrigation Area of Inner Mongolia is taken as an example. The results show that the allocated water rights of the national canals in the irrigation district are less than the current because of water-saving measures and water rights of farmer household get compensation or cut respectively. The research has fully tapped the water-saving potential of irrigation districts, refined the distribution of water rights of farmers and can provide a scientific basis for the development of water rights allocation in irrigation districts and water rights transactions between farmers.


2020 ◽  
Vol 24 (3) ◽  
pp. 67-77
Author(s):  
V. V. Devyatkov ◽  
A. V. V.Gabalin

The purpose of research. The goal of this study is to analyze different domestic software packages intended for modeling of business processes involving queues and time parameters. The main analysis criteria are: the possibility of graphical development or conversion of the business process block diagram to the model; automatic generation of simulation model; quick and convenient construction of domain-specific application; the variety of result analysis tools. The relevance of the problems to choose the optimal modeling tool is determined by the need to use only domestic software for business process investigation in the military and some scientific organizations, and by the lack of information about existing software products. In this paper, the subject of study is the Russian simulation modeling environment GPSS Studio.Materials and methods. In this article, the analysis of the possibility of effective usage of GPSS Studio environment during business processes analysis and synthesis is performed. The study was performed on the available examples of different applications of this tool, and by the creation of the model analyzing business processes that are typical for any HR department.Results. Taking into account the performed analysis of functionality and practical applications of the GPSS Studio environment, the good prospects of its application for modeling of business processes involving queues and time parameters are shown. The further system improvements intended for effective business process modeling are proposed.Conclusion. As a result of the performed study, we can do the following conclusions and recommendations:– The GPSS Studio graphical editor can be successfully used for the graphical description of the business processes when it is required to analyze: queues, the load of resources, and the time characteristics of the processing,– The simulation model is automatically generated from the graphical description. The produced model can be finally debugged and verified with the GPSS Studio,– The standalone simulation application working in terms of the subject domain can be built from the simulation model using the simulation environment,– Using this application, it is possible to perform complex business process simulation modeling by means of varying system parameters and performing of singular experiments, a series of dedicated experiments, and optimizing experiments,– Since the GPSS Studio concepts include the possibility to create domain-specific libraries of standard blocks, it is possible to create a library of standard elements similar to IDEF, BPMN, DFD block charts to facilitate faster description and modeling of business processes. After the creation of such a library, there would be no need to manually write GPSS code, since the business process model could be built by a simple connection of standard blocks.


2013 ◽  
Vol 554-557 ◽  
pp. 1045-1054 ◽  
Author(s):  
Welf Guntram Drossel ◽  
Reinhard Mauermann ◽  
Raik Grützner ◽  
Danilo Mattheß

In this study a numerical simulation model was designed for representing the joining process of carbon fiber-reinforced plastics (CFRP) and aluminum alloy with semi-tubular self-piercing rivet. The first step towards this goal is to analyze the piercing process of CFRP numerical and experimental. Thereby the essential process parameters, tool geometries and material characteristics are determined and in finite element model represented. Subsequently the finite element model will be verified and calibrated by experimental studies. The next step is the integration of the calibrated model parameters from the piercing process in the extensive simulation model of self-piercing rivet process. The comparison between the measured and computed values, e.g. process parameters and the geometrical connection characteristics, shows the reached quality of the process model. The presented method provides an experimental reliable characterization of the damage of the composite material and an evaluation of the connection performances, regarding the anisotropic property of CFRP.


2015 ◽  
Vol 669 ◽  
pp. 400-408
Author(s):  
Radoslav Krehel' ◽  
Slavko Pavlenko ◽  
Jozef Maščeník

The article contains sub-results from analyses of processes in thermodiagnostics. In this paper we give examples of the response simulation model of thermal processes on the step pulse. It describes a method of applying diagnostics in machine production. The paper describes a method of prediction values of consistently transient events that can be described by a mathematical function. This article focuses on thermal process. This gives some reasonable time to take an appropriate control plot in the desired values of variables borders. The article contains results of the simulation and plot comparison of simulation results with the measured value.


2019 ◽  
Author(s):  
Dayang Li ◽  
Zhongmin Liang ◽  
Yan Zhou ◽  
Binquan Li ◽  
Yupeng Fu

Abstract. Flood forecasting and simulation in semiarid regions are always poor, and a single criterion assessment provides limited information for decision making. Here, we propose a multicriterion assessment framework combining the absolute relative error, the flow partitioning and the confidence interval estimated by the Hydrologic Uncertainty Processor (HUP) to assess the most striking feature of an event-based flood–the peak flow. The physically based model MIKE SHE and three conceptual models (two models with a single runoff generation mechanism, the Xi’anjiang model (XAJ) and the Shanbei model (SBM), and one model with the mixed runoff generation mechanism, the vertically mixed runoff model (VMM)) are compared in terms of flood modeling performance in four semiarid catchments (Qiushui River, Qingjian River, Tuwei River and Kuye River) in the middle Yellow River. Our results show that VMM has a better flood estimation performance than the other models, and under the multicriterion assessment framework, the average acceptance of flood events accounts for 58 %, but when absolute relative error 20 % is used as the performance criterion, its figure is only 41 % in four semiarid catchments.


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