基于分层水量平衡模型的蓄水坑灌果园土壤水分动态模拟

为模拟蓄水坑灌果园土壤水分动态,实现土壤水分动态预测,基于土壤的水量平衡原理,在现有分层水量平衡模型的基础上引入局部灌溉系数ξ,对蓄水坑所在的0~70 cm土层的下渗水量进行了修正,建立了蓄水坑灌条件下0~200cm土层的分层水量平衡模型。于2015年4-10月,在山西省晋中市太谷县农业科学院果树研究所进行两个水分处理(处理一灌水上下限为田间持水量的50%~80%、处理二灌水上下限为田间持水量的60%~90%)蓄水坑灌果园水分动态监测试验。采用处理一的数据率定了模型的局部灌溉系数ξ,得到ξ的率定值为0.8,采用处理二的数据对率定后的模型进行验证,验证得到的模型均方根误差最大值为0.0074cm^(3)/cm^(3)、平均相对误差最大值为2.80%、平均绝对误差最大值为0.0064 cm^(3)/cm^(3),说明模型具有较高的模拟精度,分层水量平衡模型可以用于蓄水坑灌果园土壤水分动态模拟。两个水分处理的水分动态模拟结果显示,由于蒸发、水分下渗、根系吸水等耗水因素,随着时间的推移各层土壤含水率呈下降趋势,当有灌溉和降雨时呈上升趋势,整体来看土壤含水率在一定范围内不断波动;灌溉和降雨之后从浅到深各土层土壤含水率的增加幅度呈现了不同的趋势,灌溉之后各土层土壤含水率的增加幅度随深度先增大后减小,降雨之后各土层土壤含水率的增加幅度随深度逐渐减小;相较于中层和下层,上层土壤含水率的波动范围更大且该层土壤的平均含水率更低;处理二各层土壤的平均含水率均高于处理一。

基于分层需水的水资源均衡配置研究

水资源配置是缓解区域水资源供需矛盾、均衡水与发展的关键措施。根据新时期水资源精细化管理的有关要求,以农业、工业、生活、生态用水户为对象,基于分层需水相关理论和已有成果,提出了刚性需水、弹性需水的计算方法;综合考虑社会、经济、环境效益,构建了面向分层需水的水资源优化配置模型,采用NSGA-Ⅲ算法与EMW-TOPSIS法求解得到4种效益配置方案;以用水基尼系数表征配置单元间、用水户间的用水公平性,对非劣解集内配置方案的用水公平性进行评价,筛选出兼顾用水公平和效益的均衡配置方案;最后以宁夏回族自治区为典型研究区,进行案例应用。结果表明:均衡配置方案下,2025年宁夏全区总缺水量为10.74×10^(8)m^(3),经济效益为2182.6×10^(8)元,污染物排放量为162.78 t,该方案对应的全区用水基尼系数为0.98,配置单元间、不同用水户间用水公平性较高;与现状年相比,均衡配置方案对应的全区地下水开采量减少了0.91×10^(8)m^(3),降幅超过16.1%,地下水供水量占总供水量比例下降1.3%,进一步优化了自治区供水结构。本研究提出的水资源均衡配置思路与方法可为水资源短缺地区均衡配置提供借鉴,也可为新时期落实水资源刚性约束制度提供技术支撑。

交替沟灌玉米灌浆期茎流影响因子敏感性分析与模型适用性研究

【目的】应用人工神经网络对不同处理玉米茎流进行精准预测,为推算玉米蒸腾耗水量以及制定合理的灌水方案提供新思路。【方法】试验研究对象为夏玉米,品种为西农985。试验设置3个处理,分别为交替沟灌高水处理(alternate furrow irrigation,AFI1)、交替沟灌低水处理(alternate furrow irrigation,AFI2)和常规沟灌处理(conventional furrow irrigation,CFI)。AFI1、AFI2每次灌水量为CFI灌水量的2/3和1/2。利用通径系数与互信息分析不同处理的影响因素与玉米茎流相关关系,基于人工神经网络理论建立了玉米茎流速率估算模型,以主成分回归模型为对比,对两个模型预测精度和稳定性进行评价。【结果】(1)不同处理对环境因子的响应有所差异,影响CFI、AFI1玉米茎流的主要因素是气象因子,影响AFI2处理玉米茎流的主要因素是土壤水分;(2)不同土层含水量对各处理茎流的影响也有所不同,研究发现10—20 cm和20—30 cm土层含水量与玉米茎流相关程度最高。利用不确定性分析法进一步分析得出,常规处理与高水处理水平下,与茎液流变化关系最密切的土壤含水层为20—30 cm,其次是10—20 cm,低水处理水平下,最敏感的土层为10—20 cm,其次是20—30 cm;(3)根据模型误差分析与模型不确定性分析,神经网络模型RMSE、d-factor值较小,R2值达到了0.9以上,说明神经网络模型预测精度更高,模型更稳定。【结论】与传统方法相比,人工神经网络模型可以快速准确地对茎流进行预测,对指导玉米灌溉具有重要的指导意义。

碱/表面活性剂与聚合物交替注入技术现场应用可行性研究

为充分地发挥三元复合体系中聚合物扩大波及体积的作用,同时使具有高效洗油能力的碱/表活剂二元体系更多的进入到中、低渗透层,改善三元复合驱注入过程中注入压力高、注采能力下降幅度大、分层吸入量差异大、化学剂成本高等问题,为探索提高采收率、降低开发成本的有效途经,提出了碱/表活剂与聚合物交替注入的方式,并于2008年开展主力油层碱/表面活性剂与聚合物交替注入现场试验,研究交替注入可行性及应用效果。

注水调控技术研究与实践

自***油藏开发以来,取得了很好的开发效果。但是,随着井网的形成和高含水期的到来,开发矛盾逐步凸显,注入水和产出水大幅度增加,无效水循环严重。因此在对***油藏开发状况效果评价的基础上,深入剖析多年来的注水历程,研究注水对驱动目前油田的潜力剩余油是非常必要的。

Influence of mining thickness to the mechanical characteristics of gateways at FMTC faces

To make a better understanding of the mechanical characteristics of the surrounding rocks in the tailentry and headentry with different coal seam thickness at fully mechanized top-coal caving face （FMTC face）, the stress transition and displacement around the periphery of the gateways with different coal thicknesses were investigated in details by means of in situ measurement and 3-D numerical simulation. The research shows that the stresses decrease in the two spallings of the headentry and floor at goal with the increase in mining thickness. The roof pressure in the gates does not change obviously with the coal thickness, but the thicker the coal seam is, the farther the maximum stress will apply to the coal rib at the working face. The vertical stress is higher than the horizontal stress at two spallings of the gate, while its horizontal stress is higher than the vertical stress at the roof. The relative displacement between the roof and floor and the two spallings in the gateways increases gradually with the increase in coal seam thickness in a definite range in front of the face. Near the mining face, the stress decreases in the surrounding rock of the gates, while the deformation appears the most intensive. It is proposed that the support concept to the tailentry and headentry should be changed from loading control to deformation control.

A Pilot-scale Demonstration of Reverse Osmosis Unit for Treatment of Coal-bed Methane Co-produced Water and Its Modeling

This study presents the first demonstration project in China for treatment of coal-bed methane(CBM) co-produced water and recycling.The work aims to provide a research and innovation base for solving the pollution problem of CBM extraction water.The reverse osmosis(RO) unit is applied to the treatment of CBM co-produced water.The results indicate that system operation is stable,the removal efficiency of the total dissolved solids(TDS) is as high as 97.98%,and Fe,Mn,and F-are almost completely removed.There is no suspended solids(SS) detected in the treated water.Furthermore,a model for the RO membrane separation process is developed to describe the quantitative relationship between key physical quantities-membrane length,flow velocity,salt concentration,driving pressure and water recovery rate,and the water recovery restriction equation based on mass balance is developed.This model provides a theoretical support for the RO system design and optimization.The TDS in the CBM co-produced water are removed to meet the "drinking water standards" and "groundwater quality standards" of China and can be used as drinking water,irrigation water,and livestock watering.In addition,the cost for treatment of CBM co-produced water is assessed,and the RO technology is an efficient and cost-effective treatment method to remove pollutants.

A Discussion on Fault Activity Based on Cross-fault Observations in the Capital Circle Region of China and Its Relationship with Earthquakes

In this paper, we made a systematic study on more than 40 years of observational data of ten temporary fault-crossing measurement sites in the capital circle region of China. We calculated horizontal and vertical components of fault slip, and horizontal extension or compression components. Considering the tectonic characteristics of the capital circle region and regional seismicity, we analyzed the present fault activity of the capital circle region and the relationship with earthquakes. The results show the complexity of fault activity in the region： the level of activity of all faults is low, most faults are left-lateral strike-slip faults; there is less vertical activity than horizontal activity and crustal movement is controlled by horizontal movement; fault activity and earthquake activity have a certain relationship, regional fault activity increases before an earthquake, and fault activity has certain abnormal features before strong earthquakes.

含水量与抗剪强度关系影响下高盐量盐渍土路基边坡稳定性

针对盐渍土中不同盐分类型的溶解度和亲水性差异较大问题,分析高盐量盐渍土含水量与抗剪强度关系变化对盐渍土路基边坡稳定性的影响。结合降雨量调查和现场含水量沿深度分布情况,开展适应环境条件的室内试验。针对不同含水量条件下高氯盐渍土(CL-1)和高硫低氯盐渍土(CL-2)路基填料进行直剪试验,得出含水量与抗剪强度参数关系函数。基于Geostudio建立盐渍土路基含水量-强度参数等值分层计算模型,通过体积压力板仪试验测量土样基质吸力随体积含水量的变化规律。通过采用饱和/非饱和渗流的有限元分析与路基边坡稳定性的极限平衡分析相结合的方法,利用GeoStudio中SLOPE/W模块,分别计算和分析降雨强度、降雨持续时间等对盐渍土路基边坡稳定性的影响。考虑含水量和抗剪强度变化关系函数,通过建立的盐渍土路基含水量-强度参数等值分层计算模型对CL-1和CL-2盐渍土边坡稳定性进行了分析。结果表明:含水量在最优含水量的基础上增加3%时,CL-1和CL-2的黏聚力较最优含水量时分别下降94.3%和54.0%,内摩擦角的变化不大;在最优含水量的基础上减少3%时,CL-1和CL-2的黏聚力较最优含水量时分别提高了277.1%和89.7%,对CL-2的内摩擦角影响不大,CL-1的内摩擦角出现明显减小;当降雨强度相同时,CL-1填筑的路基的安全系数较CL-2填筑的路基变化更为明显,主要原因在于高氯盐的亲水性较硫酸盐强,抗剪强度参数受到水分变化的影响更大。

Experimental investigation of the generation of large-amplitude internal solitary wave and its interaction with a submerged slender body

A principle of generating the nonlinear large-amplitude internal wave in a stratified fluid tank with large cross-section is pro- posed according to the ＇jalousie＇ control mode. A new wave-maker based on the principle was manufactured and the experi- ments on the generation and evolution of internal solitary wave were conducted. Both the validity of the new device and ap- plicability range of the KdV-type internal soliton theory were tested. Furthermore, a measurement technique of hydrodynamic load of internal waves was developed. By means of accurately measuring slight variations of internal wave forces exerted on a slender body in the tank, their interaction characteristics were determined. It is shown that through establishing the similarity between the model scale in the stratified fluid tank and the full scale in the numerical simulation the obtained measurement re- suits of internal wave forces are confirmed to be correct.