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Comparison between gradient based UCODE2005 and the ensemble Kalman Filter for transient groundwater flow inverse modeling

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Science China Earth Sciences 2017年第5期60卷 899-909页

作者： TONG JuXiu Bill X HU yang jinzhong Key Laboratory of Groundwater Cycle and Environment Evolution (China University of Geosciences) Ministry of Education Beijing 100083 China School of Water Resources and Environment China University of Geosciences Beijing 100083 China Department of Earth Ocean and Atmospheric Science/Geological Sciences 108 Carraway Building 909 Antarctic Way Florida State University Tallahassee Florida 32306 USA State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan 430072 China

Gradient based UCODE_2005 and data assimilation based on the Ensemble Kalman Filter(EnKF) are two different inverse methods. A synthetic two-dimensional flow case with four no-flow boundaries is used to compare the UCODE_2005 with the Ensemble Kalman Filter(EnKF) for their efficiency to inversely calculate and calibrate a hydraulic conductivity field based on hydraulic head data. A zonal, random heterogeneous conductivity field is calibrated by assimilating the time series of heads observed in monitoring wells. The study results indicate that the two inverse methods, UCODE_2005 and EnKF, could be used to calibrate the hydraulic conductivity field to a certain degree. More available observations and information about the conductivity field, more accurate inverse results will be obtained for the UCODE_2005. On the other hand, for a realistic zonal heterogeneous hydraulic conductivity field, EnKF can only efficiently determine the hydraulic conductivity field at the first several assimilated time steps. The results obtained by the UCODE_2005 look better than those by the EnKF. This is possibly due to the fact that the UCODE_2005 uses observed head data at every time step, while EnKF can only use observed heads at first several steps due to the filter divergence problem.

关键词： Inverse methods UCODE2005 Ensemble Kalman Filter Heterogeneous hydraulic conductivity Filter divergence

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Evaluating the uncertainty of Darcy velocity with sparse grid collocation method

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Science China(Technological Sciences) 2009年第11期52卷 3270-3278页

作者： SHI LiangSheng yang jinzhong ZHANG DongXiao State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China Department of Energy and Resources Engineering College of EngineeringPeking UniversityBeijing 100871China

Spatial variability of Darcy velocity is presented due to the heterogeneity of aquifer parameters. The uncertainty qualification of velocity suffers great challenge in the complex porous media. This work focuses on the use of sparse grid collocation method in velocity simulation. Since the sparse grid collocation method provides a non-intrusive way to incorporate any existing deterministic solver, the mixed finite element method is combined as the deterministic solver to retain the local continuity of Darcy velocity. We decompose the error of the velocity into three components, and illustrate that the Karhunen-Loeve truncation brings more error into velocity approximation than into head. The convergence properties of velocity moments restrict the application of sparse grid collocation method in the problems with small correlation lengths. This work provides insights towards the application of sparse grid collocation method to velocity modeling. It is demonstrated that for which problems the sparse grid collocation method is expected to be competitive with the Monte Carlo simulation. Further work about the anisotropic sparse grid collocation method should be extended to circumvent the obstacle of dimensionality.

关键词： stochastic velocity uncertainty collocation sparse grid

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Experimental,numerical and sensitive analysis of nitrogen dynamics in soils irrigated with treated sewage

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Science China(Technological Sciences) 2009年第11期52卷 3279-3286页

作者： ZHU Yan yang jinzhong WANG LiYing State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China

An ammonia volatilization submodel and a crop-growth submodel have been set up and incorporated to the 2D nitrogen transport and transformation simulation model Nitrogen-2D. The coupled model Nitrogen-2D considers all the important nitrogen transformation processes such as mineralization, immobilization, denitrification, nitrification, volatilization, root uptake and soil adsorption in the soil. The model was used to simulate the nitrogen dynamics for the experiment in four lysimeters under sewage irrigation. Simulation results show that the model can describe the water content and ammonium nitrogen content distribution well but simulate the change of the nitrate nitrogen poorly. Sensitivity analysis shows that the simulation results are influenced by the soil water characteristic parameters severely, especially by the parameter of n. The model is much less sensitive to N dynamic parameters.

关键词： Nitrogen-2D nitrogen transformation and transport ammonia volatilization crop-growth model sensitivity analysis

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SOLUTE TRANSPORT THROUGH THE VADOSE ZONE:FIELD STUDIES

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Journal of Hydrodynamics 1995年第4期7卷 54-62页

作者： Ye, Zitong yang, jinzhong Zhang, Renduo Wu, Jinquan Wuhan Univ of Hydraulic and Electric Engineering Wuhan China

Solute concentration and water content profiles of an unsaturated soil were measured for a depth 170 cm within an area of 3×6 m2 at different locations. Soil water movement and solute transport in the field were studied and spatial variabilities of soil water content and concentration were discussed. Among the experiments for 33-day under constant leaching, it is shown that the effect of soil variability on soil water distribution is relatively small. However, the concentration distribution exhibits a significant variability in vertical profiles of the field. The coefficient of concentration variation is in the range of 12 to 150%, while less than 40% for water content in the same zone. The mobile and immobile water contents were calculated and related to solute transport. The immobile water content was about 24 to 39% of the total water content in the experimental field.

关键词： Flow of water Groundwater Mechanical permeability Soils Transport properties

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EXPERIMENTAL STUDIES OF SOLUTE TRANSPORT THROUGH AN UNSATURATED NATURAL SOIL

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Journal of Hydrodynamics 1996年第1期8卷 31-38页

作者： Ye, Zitong yang, jinzhong Jia, Weizhao Yan, Shilong Wuhan Univ of Hydraulic and Electric Engineering Wuhan China

Salt (NaCl) solution was applied to the surface of a cultivated field with 3 × 6 m2 and then was leached downward by a steady infiltration rate 4 mm/d. Sampling programs were designed under guiding of Dagan's scale concept. Each soil sample had eight replicates. Salt concentration exhibited a much more variability in both vertical and horizontal directions than water content, especially in the zones of peak values of concentration. The volume of immobile water, which might play an important role in the variability of concentration, was in the range of 24-39% of the total water volume in the experimental studies.

关键词： Infiltration Salt water barriers Solutions Transport properties

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CAPILLARY PRESSURE-SATURATION RELATIONSHIPS IN ROCK FRACTURE

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Journal of Hydrodynamics 1997年第1期9卷 70-74页

作者： Ye, Zitong yang, jinzhong Han, Bing Zhou, Chuangbing Wuhan Univ of Hydraulic and Electric Engineering Wuhan China

Understanding and quantifying unsaturated flow through fractures in rocky slope is important for design and construction of drainage system in large-scale hydraulic engineering. The data of the hysteretic relationship between capillary pressure and water saturation are primary for simulating unsaturated flow in fractures and analyzing the stability of high rocky slope. The drainage and imbibition curves are measured for a single fracture in granite sample got at construction site of the Three Gorges Project (TGP). The method used in this study for measuring the capillary pressure-saturation relationship, under the conditions of no normal load to rock sample, is generally following the laboratory technique developed by Reitsma and Kueper. A distinct entry pressure, indicating rise to initiate nonwetting phase invasion, was observed. The drainage curve is found to be well represented by van Genuchten porous media capillary pressure function.

关键词： Capillarity Capillary flow Flow of fluids Fracture Hydraulic structures

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*** among Dimensions of Ears and Their Form Factors in Maize(Zea Mays)Using Dimensional Analysis

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Agricultural Science & Technology 2016年第10期17卷 2287-2292页

作者： Hongbo CAO Gaimei LIANG jinzhong yang Qingdao Agricultural University/Shandong Provincial Key Laboratory of Dry Farming Techniques Qingdao 266109China Shanxi Academy of Agricultural Sciences Shanxi 030006China

Ear morphological traits such as volume and shape are important features of maize and the quantitative associations among them can help understand kernel yield determination. 150 mature ears each of 4 maize cultivars were collected from field experiments, and ear length(L), diameter(D), area(S) and volume(V) were recorded for individual ears, kernel weight per ear also recorded for a portion of the examined ears. Following principles of dimensional analysis, 8 theoretical equations of 3 sets,which relate ear higher dimensions to its length and diameter, were developed and parameterized and validated with the field observations. The 3 optimized equations showed that the shape of ears in maize can be featured with 3 dimensionless form factors, namely diameter-to-length ratio(c=D/L), areal form factor(b=S/L/D), and volumetric form factor(a=V/L/D/D). Statistically,all of them were significantly different among cultivars, and a's values varied from 0.582 to 0.612, and b's 0.839-0.868, and c's 0.242-0.308. Volumetric form factor and areal form factor could estimate precisely ear volume and area respectively, but diameter-to-length ratio was not suitable to estimate ear diameter by its length. Ear volume explained almost all variation of ear kernel weight and product L*D*D did the same substantially. Dimensional analysis proved to be promising in understanding relationship among morphological traits of ears in maize. Its application in crop researches should improve our knowledge of the physical properties of crop plants.

关键词： Maize(Zea Mays) Dimensional analysis Ear shape Volumetric form factors Ear volume Diameter-to-length ratio Ear kernel weight

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Development of Irrigation and Drainage

Development of Irrigation and Drainage

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作者： yang jinzhong

The report represents the major advances of the basic research and technique development in the field of water movement and solute transport in soils,wa- ter saving irrigation,land drainage,soil salinity control,agric...

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塑料大棚气流场模拟及作物蒸腾量计算

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农业工程学报 2011年第11期27卷 236-241页

作者：孙怀卫杨金忠王修贵华中科技大学水电与数字化工程学院武汉430074 武汉大学水资源与水电工程国家重点实验室武汉430072

为了分析塑料大棚内气流场的特征和计算与作物蒸腾量有关的通风参数,该文通过计算流体动力学模拟了塑料大棚内自然通风量,建立了华东地区常见塑料大棚内平均风速和外部风速之间的线性关系,根据能量平衡和紊流扩散模型建立了一个计算作... 详细信息

为了分析塑料大棚内气流场的特征和计算与作物蒸腾量有关的通风参数,该文通过计算流体动力学模拟了塑料大棚内自然通风量,建立了华东地区常见塑料大棚内平均风速和外部风速之间的线性关系,根据能量平衡和紊流扩散模型建立了一个计算作物蒸腾量的数学模型,并利用棚外的常规气象资料和棚内的实测温度计算了棚内作物蒸腾量。通过将作物蒸腾量的计算值和实测值进行比较,结果发现作物蒸腾量的计算值与实测值比较一致,逐日蒸腾量间的决定系数为0.7756,累积蒸腾量间的决定系数为0.9983,模拟累计值与实测累计值之间标准误差为1.16mm,最大绝对误差为4.82mm;结果表明,所建立的计算方程参数较少,推求的风速参数比较适用于普通塑料大棚。该研究可满足大棚内作物水分管理、温室大棚设计规划和区域水资源管理等方面的需要。

关键词：蒸腾量温室农作物计算模拟气流场 CFD

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基于田块尺度含水率观测的土壤水力参数多模型反演

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农业工程学报 2015年第6期31卷 135-144页

作者：刘昭杨文元查元源杨金忠武汉大学水资源与水电工程科学国家重点实验室武汉430072

该文利用反演工具UCODE与4种Richards方程数值模型(Ross模型、Picard-θ模型、Picard-mix模型和Picard-h模型)进行耦合,构建了4种不同的反演模型。基于田块尺度含水率观测数据,分别用4种反演模型优化了研究田块的土壤参数。研究结果表... 详细信息

该文利用反演工具UCODE与4种Richards方程数值模型(Ross模型、Picard-θ模型、Picard-mix模型和Picard-h模型)进行耦合,构建了4种不同的反演模型。基于田块尺度含水率观测数据,分别用4种反演模型优化了研究田块的土壤参数。研究结果表明,4种模型的反演精度依次为:Ross模型、Picard-θ模型、Picard-mix模型和Picard-h模型,但差异并不显著,反演效率以Ross模型最优。随着网格的加密,各种模型所反演参数的模拟精度改善不明显。本文还讨论了土壤水运动中"异参同效性"现象,并提出"参数曲线带"的概念——即由反求的同效参数土壤水分曲线和水力传导度曲线形成的包络图。随着模拟精度要求越高,同效参数越少,"参数曲线带"越窄,并认为反求的同效参数曲线在含水率观测信息较多的地方交汇。

关键词：土壤水分模型 Richards方程数值反演异参同效参数曲线带

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