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排灌机械工程学报 2022年第5期40卷 496-503页

作者： JIANG Ruirui FEI Liangjun KANG Shouxuan State Key Laboratory Base of Eco-hydraulic Engineering in Arid Area Xi′an University of TechnologyXi′anShaanxi 710048China

based on the experimental data,this study investigated the effect of sand content of muddy water on water and nitrogen transport characteristics of the single-line interference infiltration under film hole irrigation with muddy water and fertilizer.The relationship between the single-line interference infiltration parameters,the sand content,the wetting front movement distances,and the sand content were all established.The model of the cumulative infiltration volume of per unit film pore area,the vertical and horizontal wetting front movement distance of the free surface,and the wetting front movement distance of the interference center with sand content and infiltration time were proposed.Reveal the law of the change of soil water content and the distribution of NO_(3)^(-)-N content based on different muddy water sand content.The results indicate that at the same infiltration time,as the muddy water sand content increases,the cumulative infiltration volume per unit pore area decreases.The infiltration index of the free infiltration and the single-line interference vary little when the sand content increases,mainly are around 0.64 and 0.58.The relationship between infiltration parameters a,b and the sand content is linear function.At the same location,the more the sand content,the smaller the wetting front movement distance in free surface and the single-line interference surface,the less the NO_(3)^(-)-N content.

关键词： film hole irrigation single-line interference infiltration muddy water fertilizer sand content NO_(3)^(-)-N content

Quantitative Estimation on Contributions of Climate Changes and Human Activities to Decreasing Runoff in Weihe River Basin, China

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Chinese Geographical Science 2015年第5期25卷 569-581页

作者： HUANG Shengzhi HUANG Qiang CHEN Yutong State Key Laboratory Base of Eco-hydraulic Engineering in Arid Area Xi'an University of Technology

Human activities and climate changes are deemed to be two primary driving factors influencing the changes of hydrological processes, and quantitatively separating their influences on runoff changes will be of great significance to regional water resources planning and management. In this study, the impact of climate changes and human activities was initially qualitatively distinguished through a coupled water and energy budgets analysis, and then this effect was further separated by means of a quantitative estimation based on hydrological sensitivity analysis. The results show that: 1) precipitation, wind speed, potential evapotranspiration and runoff have a significantly decreasing trend, while temperature has a remarkably increasing tendency in the Weihe River Basin, China; 2) the major driving factor on runoff decrease in the 1970 s and 1990 s in the basin is climate changes compared with that in the baseline 1960 s, while that in the 1980 s and 2000 s is human activities. Compared with the results based on Variable Infiltration Capacity(VIC) model, the contributions calculated in this study have certain reliability. The results are of great significance to local water resources planning and management.

关键词：人类活动气候变化流域径流渭河流域定量估算水资源规划流域水文敏感性分析

Effects of arrangement of surge-root irrigation emitters on growth,yield and water use efficiency of apple trees

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排灌机械工程学报 2020年第7期38卷 713-719页

作者： LI Zhongjie FEI Liangjun HAO Kun LIU Teng CHEN Nanshu ZHANG Quanju HUANG Deliang State Key Laboratory Base of Eco-hydraulic Engineering in Arid Area Xi′an University of TechnologyXi′anShaanxi 710048China

Six-year old apple trees were selected for field experiment.The objective of this study was to obtain the reasonable arrangement of surge-root irrigation emitters in apple orchards.There were three factors:the buried depth H(25,40,55 cm),the horizontal distance L(30,40,60 cm)between the emitters and the trunk of the experimental tree,and the number of the irrigation emitters N(1,2,4).The effect of the arrangement of surge-root irrigation emitters on the growth,yield and irrigation water use efficiency(IWUE)of apple trees were studied in Northern Shaanxi where the irrigation quota takes 60%-75%of the field water capacity.The results showed that the arrangement of emitters for surge-root irrigation had a significant effect on apple tree yield and IWUE,especially,the yield and IWUE reached 28388.17 kg/hm2 and 16.83 kg/m3 in treatment T3,respectively.At the same L and N levels(T1,T2,and T3),the yield and IWUE in treatment T3 were the highest,and the yields in treatments T1 and T2 were decreased by 26.22%and 31.48%,while IWUE is reduced by14.02%and 18.12%compared with T3,respectively.At the same H and N levels(T3,T4,and T5),the yield and IWUE of apple trees were decreased with increasing L level.Especially,when L was 30 cm(T3),the yield and IWUE were the highest.The same L and H levels(T3,T6,and T7)could promote the growth of apple trees when N was 2(T3).Compared with treatment T3,it was found that the increment of new shoots was decreased by 8.07%-18.71%,and the fruit diameter was decreased by 5.41%-9.11%.Therefore,two emitters should be arranged symmetrically on both sides of an apple tree,each was buried at a 40 cm depth and 30 cm away from the trunk of the tree to effectively improve the yield and IWUE of the apple tree in mountainous areas in Northern Shaanxi.

关键词： irrigation emitters surge-root irrigation apple trees arrangement modes yield irrigation water use efficiency

Effects of urban grass coverage on rainfall-induced runoff in Xi'an loess region in China

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Water Science and engineering 2017年第4期10卷 320-325页

作者： Jing Li, Zhan-bin Li Meng-jing Guo Peng Li Sheng-dong Cheng State Key Laboratory Base of Eco-hydraulic Engineering in Arid Areas Xi'an University of TechnologyXi'an 710048China

In this study, laboratory rainfall simulation experiments were conducted to investigate the regulatory effects of grass coverage on rainfallrunoff processes. A total of 80 grass blocks planted with well-grown manilagrass, together with their root systems, were sampled from an eastern suburban area of Xi'an City in the northwest arid area of China and sent to a laboratory for rainfall simulation experiments. The runoff and infiltration processes of a slope with different grass coverage ratios and vegetation patterns were analyzed. The results show that the runoff coefficient decreases with the increase of the grass coverage ratio, and the influence of grass coverage on the reduction of runoff shows a high degree of spatial variation. At a constant grass coverage ratio, as the area of grass coverage moves downward, the runoff coefficient, total runoff,and flood peak discharge gradually decrease, and the flood peak occurs later. With the increase of the grass coverage ratio, the flood peak discharge gradually decreases, and the flood peak occurs later as well. In conclusion, a high grass coverage ratio with the area of grass coverage located at the lower part of the slope will lead to satisfactory regulatory effects on rainfall-induced runoff.

关键词： Rainfall simulation Urban vegetation in arid area Rainfall-runoff process Regulatory effect Xi'an loess region

Experimental investigation of velocity fluctuations in a radial diffuser pump

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Journal of Hydrodynamics 2015年第3期27卷 332-339页

作者：冯建军罗兴锜 BENRA Friedrich-Karl DOHMEN Hans-Josef State Key Laboratory Base of Eco-hydraulic Engineering in Arid Area Xi'an University of Technology Department of Mechanical engineering Faculty of Engineering University of Duisburg-Essen

The strong interaction in a radial pump due to the relative movement between the impeller and the diffuser may excite not only strong pressure fluctuations but also velocity fluctuations. In this paper, the laser Doppler velocimetry （LDV） technique is successfully applied to measure the periodic flow field in a radial diffuser pump with low-specific speed, in order to investigate the velocity fluctuations caused by the impeller-diffuser interactions both in the impeller and diffuser regions. The velocity fluctuations in the impeller region are quantitatively examined at different radial positions, and the flow structure at the radial gap between two flow components is analyzed at different relative positions. In addition, the downstream effect on the diffuser flow is quantitatively and qualitatively assessed and compared with the turbulence effect.

关键词： laser Doppler velocimetry （LDV） radial pump impeller-diffuser interaction velocity fluctuations

Numerical investigation of the effect of T-shaped blade on the energy performance improvement of a semi-open centrifugal pump

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Journal of Hydrodynamics 2021年第4期33卷 736-746页

作者： Li-ke Wang Jin-ling Lu Wei-li Liao Peng-cheng Guo Jian-jun Feng Xing-qi Luo Wei Wang State Key Laboratory Base of Eco-hydraulic Engineering in Arid Area Xi’an University of TechnologyXi’an710048China Institute of Water Resources and Hydro-electric engineering Xi’an University of TechnologyXi’an710048China

The tip leakage flow formed by the tip clearance of a semi-open centrifugal pump adversely affects the energy performance and the energy waste. A T-shaped blade is proposed to be used to improve the energy characteristics. The internal flow field is simulated via the shear stress transport turbulence model to analyze the influence of the T-shaped blade on the performance of a centrifugal pump. It is shown that with the T-shaped blade, the hydraulic loss can be reduced, the Euler head can be increased, and the external characteristics can be improved. The maximum head and efficiency improvements are 3% and 1.6%, respectively. The relative flow angle near the tip clearance of the T-shaped blade decreases, and the strength of the backflow region is remarkably weakened. The area of the high entropy production region decreases, and the trend of the upstream diffusion is restrained under the design condition. The T-shaped blade can help to inhibit the diffusion of the high entropy production region to the hub under the low flow rate condition, but the entropy production and the mixing losses at the tip clearance are slightly increased. This research provides a new method for improving the energy performance of the semi-open centrifugal pump.

关键词： Centrifugal pump tip leakage flow entropy production backflow

Identification of impacts of climate change and direct human activities on streamflow in Weihe River Basin in Northwest China

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International Journal of Agricultural and Biological engineering 2017年第4期10卷 119-129页

作者： Fan Jingjing Huang Qiang Liu Dengfeng Hebei University of engineering Handan 056038China State Key Laboratory Base of Eco-hydraulic Engineering in Arid Area Xi’an University of TechnologyXi’an 710048China

Climate change and human activities make major influences on hydrology,which are known to have important impacts on streamflow variation.Therefore,it is critically important to identify how climate change and human activities will impact streamflow variation.Thus,the goal of this study is to identify the impacts of climate change and direct human activities on annual streamflow at four hydrologic stations in the Weihe River basin of China,with the estimation of evaporation based on the Budyko hypothesis.The Mann-Kendall test was employed to detect the break points of the four stations.According to the occurrence time of break points,the data series were divided into two periods:pre-change period(1960-1984)and post-change(1985-2010)period.The parameter of one-parameter Budyko-type model was calibrated with observed data during the pre-change period,with the R^(2) values ranged from 0.95 to 0.97 and the NSE values ranged from 0.80 to 0.94,and the high R^(2) and Nash-Sutcliffe Efficiency coefficient shows the model has good performance.The contribution ratios of climate change impacts on decreasing streamflow were 37%,23%,57%and 43%,and those of the impacts of direct human activities were 63%,77%,43%and 57%for the Linjiacun,Xianyang,Lintong and Huaxian station,respectively.Both the climate change and direct human activities have positive impacts on streamflow decrease at all of the four stations,and the direct human activities are the main factor causing the decrease of annual streamflow.

关键词： streamflow,climate change human activities evaporation,hydrological cycle,watershed,Budyko hypothesis,Weihe River basin

Experimental and numerical study regarding H-steel all-bolted connection steel frame with composite wall boards

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Earthquake engineering and engineering Vibration 2024年第2期23卷 427-443页

作者： Fan Min Guo Hongchao Li Shen Wang Zhenshan Wang Huaqiang School of Civil engineering and Architecture Xi’an University of TechnologyXi’an 710048China State Key Laboratory Base of Eco-hydraulic Engineering in Arid Area Xi’an University of TechnologyXi’an 710048China

H-steel all-bolted connection steel frame structures with heat preservation and decoration composite wall boards were investigated and the seismic performances of three scaled specimens were studied.The failure modes,hysteresis curves,bearing capacity,ductility,energy dissipation capacity,stiffness degradation and strain distribution were discussed.The calculation method of structural theoretical internal force was presented.The results showed that the overall structural seismic performance was better,and the structural ductility met the demands of elastic-plastic inter-story drift angle for seismic design.The H-steel weak-axis connection structure obtained better energy dissipation capacity,and its bearing capacity and stiffness were slightly different from the strong-axis connection.The heat preservation and decoration performance of composite wallboard and the all-bolted connection of the steel frame realized prefabrication during the whole construction period.The plastic hinge of the steel beam can be moved outwards because of the L-angles,which effectively avoids stress concentration in joint areas and expands the plastic hinge range.The errors between the theoretical structural capacity calculated by the plastic analysis method and the test results were within 2.44%.In addition,structural failure mechanisms and bearing capacities were verified by the finite element(FE)analysis,and the effects of the main parameters on the structures were investigated.The FE verification results were the same as in the test.The research results provide theoretical support and technical guidance for the application of thermal insulation and decorative composite wall panels in H-shaped steel all-bolted steel frames.

关键词： composite wall boards all-bolted steel frame H-steel low-cyclic loading failure modes

Effects of freeze-thaw on soil erosion processes and sediment selectivity under simulated rainfall

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Journal of arid Land 2017年第2期9卷 234-243页

作者： WANG Tian LI Peng REN Zongping XU Guoce LI Zhanbin YANG Yuanyuan TANG Shanshan YAO Jingwei State Key Laboratory Base of Eco-hydraulic Engineering in Arid Area Xi’an University of Technology state key laboratory of Soil Erosion and Dry-land Farming on the Loess Plateau Institute of Soil and Water ConservationChinese Academy of Sciences and Ministry of Water Resources

The freeze-thaw （FT） processes affect an area of 46.3% in China. It is essential for soil and water conservation and ecological construction to elucidate the mechanisms of the FF processes and its associated soil erosion processes. In this research, we designed the control simulation experiments to promote the understanding of FT-water combined erosion processes. The results showed that the runoff of freeze-thaw slope （FTS） decreased by 8% compared to the control slope （CS）, and the total sediment yield of the FTS was 1.10 times that of the CS. The sediment yield rate from the FTS was significantly greater than that from the CS after 9 min of runoff （P〈0.01）. Both in FTS and CS treatments, the relationships between cumulative runoff and sediment yield can be fitted well with power functions （R2〉0.98, P〈0.01）. Significant differences in the mean weight diameter （MWD） values of particles were between the CS and the FTS treatments in the erosion were smaller than those under FTS for both washed and observed for washed particles and splashed particles process （P〈0.05）. The mean MWD values under CS splashed particles. The ratio of the absolute value of a regression coefficient between the CS and the FTS was 1.15, being roughly correspondent with the ratio of K between the two treatments. Therefore, the parameter a of the power function between cumulative runoff and sediment yield could be an acceptable indicator for expressing the soil erodibility. In conclusion, the FTS exhibited an increase in soil erosion compared to the CS.

关键词： freeze-thaw erosion loess soil soil erodibility runoff sediment size-selectivity rainfall simulation

The response of soil organic carbon to climate and soil texture in China

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Frontiers of Earth Science 2022年第4期16卷 835-845页

作者： Yi ZHANG Peng LI Xiaojun LIU Lie XIAO Tanbao LI Dejun WANG State Key Laboratory Base of Eco-hydraulic Engineering in Arid Area Xi’an University of TechnologyXi’an 710048China state key laboratory of National Forestry and Grassland Administration on ecological Hydrology and Disaster Prevention in arid Regions Xi’an 710048China Forestry College Jiangxi Agricultural UniversityNanchang 330045China Northwest Surveying Planning and Designing Institute of National Forestry and Grassland AdministrationXi’an 710048China

Soil organic carbon(SOC)plays an essential role in the carbon cycle and global warming mitigation,and it varies spatially in relation to other soil and environmental properties.But the national distributions and the impact mechanisms of SOC remain debated in China.Therefore,how soil texture and climate factors affect the SOC content and the regional differences in SOC content were explored by analyzing 7857 surface soil samples with different land-use.The results showed that the SOC content in China,with a mean value of 11.20 g·kg^(-1),increased gradually from north to south.The SOC content of arable land in each geographical area was lower than in grassland and forest-land.Although temperature also played a specific role in the SOC content,precipitation was the most critical climate factor.The SOC content was positively correlated with the silt and clay content.The lower the temperature,the greater the effect of environmental factors on SOC.In contrast,the higher the temperature,the more significant impact of soil texture on SOC.The regional difference in SOC highlights the importance of soil responses to climate change.Tempera-ture and soil texture should be explicitly considered when predicting potential future carbon cycle and sequestration.

关键词： soil organic carbon climate soil texture land use