泾惠渠灌区土壤入渗参数及灌水技术参数优化研究

发布时间：2018-06-05 04:49

本文选题：畦灌 + 土壤入渗　；参考：《西北农林科技大学》2016年硕士论文

【摘要】：在我国95%的灌溉面积采用地面灌溉方式。泾惠渠灌区作为关中九大灌区之一的大(Ⅱ)型灌区,灌溉方式主要以传统的地面灌溉为主,灌区水源工程单一,河源水利用率低,田间工程设施不完善。同时,随着土壤翻耕措施,灌溉,降雨,农作物生长等影响,导致土壤结构改变,土壤水分入渗性能及其田面糙率系数在年内差异显著,而该灌区入畦流量在年内基本保持不变,从而导致了灌区灌水技术参数的不合理性,造成了灌水质量评价指标不高,田间水灌溉利用效率低,水分深层渗漏损失严重等问题。随着灌区水资源供需矛盾日益突出的条件下,研究灌区畦田节水灌溉关键技术,对建设泾惠渠节约型生态灌区具有重要的意义。本文针对上述问题,利用常用的地面灌溉模拟软件Win SRFR4.1对该灌区不同灌水时期土壤入渗参数、田面综合糙率系数等关键技术参数进行了优化研究;分析了不同灌季土壤入渗参数及其田面综合糙率系数的时间变异程度,模拟研究了时间变异性因子对灌水质量评价指标的影响及其在不同灌水季节的灌水效果;针对不同灌季土壤入渗参数值及其田面综合糙率系数的变异性对该灌区进行了灌水技术参数优化组合研究。本文的主要研究成果有:(1)通过田间实测水流推进、消退数据,利用Win SRFR4.1可以较好地模拟优化出考斯加科夫土壤入渗模型参数值,水流推进及消退过程模拟结果与实测结果吻合度较好。基于此,对不同灌水时期的入渗参数值进行了优化求解,考斯加科夫模型入渗系数值及入渗指数值平均变化范围分别在95.0~210.0mm?hr-1和0.42~0.67之间。(2)在夏玉米—冬小麦轮作周期内,由于农耕、灌溉、降雨等因素的影响,耕作层土壤容重存在周期性变化特性,最小值出现在土地深翻冬小麦播种时期为1.15g/cm3,最大值在夏玉米后期为1.35g/cm3,并趋于稳定。利用耕作层土壤容重及土壤质量含水量与土壤入渗参数值进行回归拟合表明,考斯加科夫土壤入渗模型两参数值的回归模型拟合度较好,校正R2值分别为0.846和0.741,由此可以在不同的灌水时期通过测量田间耕作层土壤容重以及土壤质量含水率,确定考斯加科夫土壤入渗模型参数值。(3)对灌区土壤入渗参数值及田面综合糙率系数进行时间变异性分析表明,不同灌水时期土壤水分入渗模型系数K、入渗指数α及田面综合糙率系数值n差异性较为显著,均达到了中等变异程度。通过模拟分析比较土壤水分入渗参数值及田面糙率系数对灌水质量的影响,表明单个时间变异性因子对灌水效率、灌水均匀度、储水效率均有较大的影响,在优化灌水技术参数时,不能忽略这些因子的变异性对灌水质量的影响。(4)不同灌水时期,土壤水分入渗参数值及田面糙率系数的综合变异性作用对畦灌水流推进、消退过程、土壤受水时间及灌水质量评价指标均达到了显著性的影响。基于此,利用WinSRFR4.1模型针对不同畦长,不同灌水时期,不同灌水定额条件下,以入畦单宽流量和改水成数为变量分别进行了灌水技术参数优化组合研究,优化结果表明灌水质量得到了明显的提高,灌溉效果达到了较好的效果。
[Abstract]:In China, 95% of the irrigation area is used in the way of ground irrigation. Jinghui irrigation area is one of the big (II) irrigation areas of one of the ninth big irrigation areas in Guanzhong. The irrigation mode is mainly based on the traditional ground irrigation, the water source project of the irrigation area is single, the water utilization rate of Heyuan is low, and the field engineering facilities are not perfect. The effects of growth, such as soil structure change, soil water infiltration performance and field roughness coefficient are significant in year, but the flow rate of the irrigation area is basically unchanged during the year, which leads to the irrationality of irrigation technical parameters in irrigation area, which results in low evaluation index of irrigation quality, low efficiency of irrigation and utilization of field water and deep water. Under the condition that the contradiction between the supply and demand of water resources is becoming more and more serious in the irrigation area, it is of great significance to study the key technology of water saving irrigation in the border area of irrigation area, which is of great significance to the construction of the economized ecological irrigation area of Jinghui canal. In this paper, the common ground irrigation model software Win SRFR4.1 is used for the different irrigation period in this irrigation area. The key technical parameters such as soil infiltration parameters and field surface roughness coefficient are optimized, and the time variation degree of soil infiltration parameters and field roughness coefficient of different irrigation seasons is analyzed. The influence of time variability factors on the evaluation indexes of irrigation quality and the irrigation effect in different irrigation seasons are simulated and studied. The optimum combination of irrigation technical parameters in this irrigation area is studied in different irrigation season soil infiltration parameters and the variability of soil surface roughness coefficient. The main research results of this paper are as follows: (1) through field measurement of water flow and regression data, the parameters of Coss Fagafaga Kopf soil infiltration model can be simulated and optimized by Win SRFR4.1. The simulation results of flow propulsion and regression are in good agreement with the measured results. Based on this, the infiltration parameters of different irrigation periods are optimized. The average variation range of Coss Fagafaga Kopf model infiltration system value and infiltration finger value is between 95.0~210.0mm? HR-1 and 0.42~0.67 respectively. (2) in summer maize Winter Wheat rotation week During the period, due to the influence of farming, irrigation and rainfall, the soil bulk density of the tillage layer has a periodic variation. The minimum value is 1.15g/cm3 in the period of land deep turn winter wheat, and the maximum value is 1.35g/cm3 in the late summer of summer corn, and tends to be stable. The regression fitting shows that the regression model of the two parameter regression model of the Coss Fagafaga Kopf soil infiltration model is better, and the corrected R2 values are 0.846 and 0.741 respectively. Thus, the parameters of the koskoff soil infiltration model can be determined by measuring the soil bulk density and the soil mass moisture content in the different irrigation periods. (3) the soil of the irrigation area soil can be determined. The time variability analysis of soil infiltration parameter and field surface roughness coefficient showed that the coefficient of soil water infiltration model was K, infiltration index alpha and field surface roughness system n difference were more significant, and all reached medium variation degree. The simulation analysis compared soil water infiltration parameter and field roughness coefficient. The influence on irrigation quality shows that the single time variation factor has great influence on irrigation efficiency, irrigation uniformity and water storage efficiency. When optimizing irrigation technical parameters, the influence of the variability of these factors on irrigation quality can not be ignored. (4) the comprehensive change of soil water infiltration parameter and field roughness coefficient in different irrigation period. The effect of the heterosexual action on the flow of border irrigation and the regression process, the soil water time and the evaluation index of water quality have reached significant influence. Based on this, the WinSRFR4.1 model is used to carry out the irrigation technical parameters for the different border length, different irrigation period and different irrigation quota, with the wide flow of border and the number of water change as the variables. The optimization results show that the irrigation quality has been significantly improved, and the irrigation effect has achieved good results.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S275;S152.72

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