Key Laboratory for Agricultural Soil and Water Engineering in Arid Area of Ministry of Education

Yangling, China

Key Laboratory for Agricultural Soil and Water Engineering in Arid Area of Ministry of Education

Yangling, China
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Xing X.,Key Laboratory for Agricultural Soil and Water Engineering in Arid Area of Ministry of Education | Zhao W.,Key Laboratory for Agricultural Soil and Water Engineering in Arid Area of Ministry of Education | Ma X.,Key Laboratory for Agricultural Soil and Water Engineering in Arid Area of Ministry of Education | Ma X.,Northwest University, China | Zhang Y.,Northwest University, China
Shuili Xuebao/Journal of Hydraulic Engineering | Year: 2015

Clay loam soil from Yunnan (KM), sandy loam soil from Liaoning (SY) and Xinjiang (KL), and loam soil from Shandong (LY) were selected for analyzing the characteristics of soil shrinkage during soil water characteristic curve measurement in order to explore the suitability of fitting models for soil water characteristic curve, and the changes of soil shrinkage. In this paper, soil water characteristic curves of the four soil types were measured by centrifuge method and were fitted by RETC software. The results showed that as for KM, SY, KL and LY soils, firstly, soil moisture content gradually decreased with soil suction increasing from 0 to 7000 cm. And the rate of soil water reduction decreased, and then increased, and then decreased again. Secondly, all fitting models presented in RETC software were of high accuracy for the simulation of soil water characteristic curves, and the appropriate fitting models for KM, SY, KL and LY soils were VG-M (m, n), LND-M, VG-M (1-1/n, n) and VG-B (m, n), respectively. And VG model could be considered as the optimal model for simulation of soil water characteristic curves of the four soils. Thirdly, a logarithmic function was found between degree of effective soil shrinkage and soil suction during soil water characteristic curve measurement. The soil shrinkage was ranked in the order of SY > KM > LY > KL, and the bulk density of the four soils increased by 0.19~0.46 g/cm3. Fourthly, soil shrinkage process could be roughly divided into pseudo-saturated stage, structural stage and super-normal stage. And as for KM, SY, KL and LY soils, the three stages could be described by linear function, but the ranges of soil suction corresponding to three soil shrinkage stages were different. © 2015, China Water Power Press. All right reserved.


Nie W.,Xi'an University of Technology | Fei L.,Xi'an University of Technology | Ma X.,Key Laboratory for Agricultural Soil and Water Engineering in Arid Area of Ministry of Education
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2011

Based on the principle of water volume balance and kinematic-wave (KW) model, those models are disposed with dimensionless, which to improve simulation accuracy of water movement process with water volume balance model. The changes of surface shape factor were studied and it could be computed with empirical formula which was proposed in this paper. Research results showed that the surface shape factor was not a constant value, but a variable value with the change of irrigation time, water advance distance and other factors. The validity of the proposed method was verified by some research materials, the results showed that the precision of the model could be improved when the variation of surface shape factor was considered using volume balance model and the empirical formula proposed. The model was applied to estimate water surface shape factor for forder irrigation was reliable.


Nie W.,Xi'an University of Technology | Ren C.,Xi'an University of Technology | Fei L.,Xi'an University of Technology | Ma X.,Key Laboratory for Agricultural Soil and Water Engineering in Arid Area of Ministry of Education
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2014

Border irrigation, a method of plant irrigation, is widely used in China because of its low cost and energy consumption. Water scarcity and the high consumption of water resources in agriculture can lead to the low irrigation performance which has strengthened the need to manage and optimize irrigation systems. Moreover, border irrigation performance can be affected by factors such as soil infiltration parameter, Manning roughness and micro topography of field. These factors were spatial variable, which causes difficulties in design and management of the border irrigation system. Based on the field experiments, the objectives of this study were to propose three functions for estimation of border irrigation performance indicators (application efficiency, uniformity distribution and storage efficiency) under the closed-end condition of the border, by employing the method of dimensional analysis and numerical simulation with the WinSRFR software. The independent irrigation variables are inflow charge per width q, cut-off time t, Manning roughness n, infiltration parameter k, infiltration index a, border length L, filed slope S0 and the required water depth Zr effective on the indicators of irrigation application efficiency Ea and storage efficiency Es. While for the uniform distribution DU, the independent irrigation variables of function are inflow charge per width q, cut-off time t, Manning roughness n, infiltration parameter k, infiltration index a, border length L and filed slope S0. The proposed functions were used to estimate irrigation performance of the different combinations of border irrigation technique elements, and the results showed that the estimated values of irrigation performance agreed well with the simulated values with the zero inertia. The average absolute errors between the estimated values of irrigation performance and the simulated values were 6.72%, 6.57%, and 4.93%, and the determination coefficient R2 were 0.987, 0.969, and 0.990, respectively. The significance test of difference between the estimated values of irrigation performance and the simulated values had been conducted using SPSS software (P=0.05), the significance indexes of the estimated and simulated values of the irrigation application efficiency Ea, uniform distribution DU and storage efficiency Es were 0.226, 0.142, and 0.271, respectively. The results showed no significant difference between the estimated values and the simulated values of irrigation performance. The reliability of the functions proposed here was verified based on basic parameters of border irrigation. The results showed the estimated values of irrigation application efficiency Ea, uniform distribution DU and storage efficiency Es with the proposed functions of this paper were in excellent agreement with the measured values, and the average absolute errors between the estimated values and the measured values of irrigation performance were 7.76%, 9.15%, and 7.08%, respectively. Therefore, three functions proposed here for estimation of border irrigation performance indicators were highly reliable and universal.


Nie W.,China University of Technology | Fei L.,China University of Technology | Ma X.,Key Laboratory for Agricultural Soil and Water Engineering in Arid Area of Ministry of Education
Spanish Journal of Agricultural Research | Year: 2014

Evaluation of furrow irrigation systems requires accurate estimation of soil infiltration parameters and Manning roughness, and the impact of variations of those parameters should be considered. The objectives of this paper were to verify the reliability of the infiltration parameters and Manning roughness estimated with SIPAR_ID software, and to analyze the impacts of different combinations between soil infiltration parameters and Manning roughness on the water trajectory and irrigation performance for closed-end furrows. The study consisted of field experiments and numerical simulation. Field experiments using Fuji apple trees were conducted in three villages of the Yangling district in October 2007. Infiltration parameters and Manning roughness were estimated with SIPAR_ID software. The estimated values were input into the WinSRFR software, and the advance trajectory and flow depths in the upstream were simulated on each furrow. The results show that the simulated values with WinSRFR software were in good agreement with measured data. Thus, the infiltration parameters and Manning roughness estimated with SIPAR_ID software were reliable. It was found that the water advance trajectory and the irrigation performance were not sensitive to variations of Manning roughness, but they were very sensitive to the variation of soil infiltration parameters laterally across the field between the furrows. Therefore, the average of Manning roughness on the whole field can be used as a representative value to simulate the advance trajectory and irrigation performance for every furrow. However, during the simulations, the variations of the soil infiltration parameters for different furrows across the field must be taken into account. Otherwise, significant errors can be produced in the simulated water advance trajectory and irrigation performance. © 2014 Ministerio de Agricultura Pesca y Alimentacion. All Rights Reserved.

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