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Responses of flood peaks to land use and landscape patterns under extreme rainstorms in small catchments-A case study of the rainstorm of Typhoon Lekima in Shandong,China

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International soil and water conservation Research 2022年第2期10卷 228-239页

作者： Yuanhao Liu Jianqiao Han Juying Jiao Baoyuan Liu Wenyan Ge Qingbin Pan Fei Wang Institute of soil and water conservation Northwest A&F UniversityYangling712100Shaanxi ProvinceChina Key Laboratory of the Loess Plateau soil Erosion and water Loss Process and Control Ministry of Water ResourcesZhengzhou450003Henan ProvinceChina Institute of soil and water conservation Chinese Academy of Sciences and Ministry of Water ResourcesYangling712100Shaanxi ProvinceChina China Institute of water Resources and Hydropower Resea

Investigations of the formation mechanisms of flood peaks in small catchments facilitate flood prediction and disaster prevention under extreme rainstorms.However,there have been few studies on the re-sponses of flood peaks to land use landscape patterns using field surveys during extreme rainstorm events.Based on field data from 17 small catchments near the rainstorm center of Typhoon Lekima,7 landscape indices were chosen.The flood peak and its sensitivity to the land use landscape were investigated by combining remote sensing interpretation and related analysis.The conclusions are as follows:(1)The peak discharge of the small catchment was 2.36e56.50 m3/s,the peak modulus was 8.00 e48.89 m3/(s$km2),and the flood index K ranged from 3.61 to 4.55.(2)Under similar rainfall conditions,the flood peak modulus,K and the proportion of sloping cropland had significantly positive correlations(p<0.05).The flood peak modulus was significantly negatively correlated with the proportion of forest-grassland and terrace(p<0.05),and K and the proportion of forest-grassland and terraced land exhibited a negative correlation.(3)The flood peak modulus and K were positively correlated with the landscape fragmentation.(4)The sensitivities of small catchments to floods were evaluated to be moderate compared to K values from other studies.The ability of small catchments to cope with extreme rain-storms can be improved by increasing the areas of forest-grassland,and terraces and reducing landscape fragmentation.Our results could be applied to provide a basis for land use planning and support for the response against disasters caused by extreme floods.

关键词： Extreme rainstorm Flood peak intensity Flood peak sensitivity Land use Landscape pattern

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Decoupling effects of driving factors on sediment yield in the Chinese Loess Plateau

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International soil and water conservation Research 2023年第1期11卷 60-74页

作者： Xiaojing Tian Guangju Zhao Xingmin Mu Pengfei Zhang Peng Gao Wenyi Sun Xiaoyan Lu Peng Tian State Key Laboratory of soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationNorthwest A&F University26 Xinong RoadYangling712100Shaanxi ProvinceChina Institute of soil and water conservation Chinese Academy of Sciences and Ministry of Water Resources26 Xinong RoadYangling712100Shaanxi ProvinceChina Yangtze Ecology and Environment Co Ltd.Wuhan430000Hubei ProvinceChina Erdos Hydrological Survey bureau of Inner Mongolia Autonomous Region Erdos017010Inner MongoliaChina College of Natural Resources and Environment Northwest A&F University3 Taicheng RoadYangling712100Shaanxi ProvinceChina

Investigations of runoff and sediment yield changes and their relationships with potential driving factors provide good insights for understanding the mechanisms of hydrological processes.This study attempted to present a comprehensive investigation on the spatiotemporal variations of sediment yield in the Loess Plateau using continuous observed data at 46 hydrological stations during 1961-2016,and its responses to changes of precipitation,land use/cover and vegetation cover were analyzed by using the Partial Least Squares-Structural Equation Model(PLS-SEM).The results indicated that sediment yield reduced pro-nouncedly during 1961-2016 in the Loess Plateau,and 77.9%of this variation was explained by the combined effects of precipitation,land-use change,vegetation dynamics and runoff reduction.Indirect effects of precipitation,land-use change,and vegetation cover on sediment yield were 0.242,-0.528 and-0.630(Psoil erosion.However,lower correlations were examined between sediment yield and precipitation indices(-0.14soil and water conservation planning in the Loess Plateau,and are valuable for sus-tainable water resources and sediment load management in the Yellow River Basin.

关键词： Sediment yield Driving factors Correlation analysis PLS-SEM Loess Plateau

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Anti-clogging ability of the labyrinth emitter and its evaluation method

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International Journal of Agricultural and Biological Engineering 2022年第6期15卷 80-90页

作者： Wenqian Zhang Zhaoxi Wang Senhao Cheng Aihong Dong Erxin Zhang Wenquan Niu Key Laboratory of Agricultural soil and water Engineering in Arid and Semiarid Areas Ministry of EducationNorthwest A&F UniversityYangling 712100ShaanxiChina College of water Resources and Architectural Engineering Northwest A&F UniversityYangling 712100ShaanxiChina Institute of soil and water conservation Chinese Academy of Science and Ministry of Water Resources of the People’s Republic of ChinaYangling 712100ShaanxiChina Institute of soil and water conservation Northwest A&F UniversityYangling 712100ShaanxiChina

Emitter clogging is one of the most serious factors that restrict the drip irrigation system operation and water use efficiency.To scientifically characterize and evaluate emitter clogging risk,a literature review,short-period emitter anti-clogging tests,and CFD(Computational Fluid Dynamics)hydraulic performance tests were conducted.Results showed that the emitter anti-clogging ability is related to its structure,material,and processing technology,not external factors.This was evidenced in the irrigation tests,as with the different water qualities,the same emitters were repeatedly prone to clog or to avoid clogging.A predictive model of structural resistance coefficient(Cs),a quantitative indicator of the emitter anti-clogging ability,whose value ranges between 0 and 1,was utilized.Larger Cs values indicate a lower anti-clogging ability and thus a higher risk of clogging.A good linear relationship between Cs and the relative flow rate was detected,and the Cs relationship with the fluidity index(x)was determined to be a power function.The Cs should be controlled within the range of 0.146-0.461 when designing new emitters to ensure that they have good anti-clogging properties.This research will provide theoretical guidance for the anti-clogging management of drip irrigation systems and for the design of optimal emitter structures.

关键词： drip irrigation system structural resistance coefficient emitter clogging risk energy loss anti-clogging ability

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Prediction of the Maturity of Greenhouse Grapes Based on Imaging Technology

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Plant Phenomics 2022年第1期4卷 357-370页

作者： Xinguang Wei Linlin Wu Dong Ge Mingze Yao Yikui Bai College of water Conservancy Shenyang Agricultural UniversityShenyang 110866China Institute of soil and water conservation Northwest A&F University712100YanglingShaanxi ProvinceChina

To predict grape maturity in solar greenhouses,a plant phenotype-monitoring platform(Phenofix,France)was used to obtain RGB images of grapes from expansion to maturity.Horizontal and longitudinal diameters,compactness,soluble solid content(SSC),titratable acid content,and the SSC/acid of grapes were measured and evaluated.The color values(R,G,B,H,S,andI)of the grape skin were determined and subjected to a back-propagation neural network algorithm(BPNN)to predict grape maturity.

关键词： maturity greenhouse content

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N and P resorption as functions of the needle age class in two conifer trees

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Journal of Plant Ecology 2018年第5期11卷 780-788页

作者： Zhiyou Yuan Xinrong Shi Feng Jiao Fengpeng Han State Key Laboratory of soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationNorthwest A&F UniversityYanglingShaanxi 712100China Institute of soil and water conservation Chinese Academy of Science and Ministry of Water ResourceYanglingShaanxi 712100China

Aims Given the importance of resorption in nutrient conservations,nu-trient resorption should change with leaf age if resorption depends on nutrient content,and if nutrient content changes with leaf age.However,no study has addressed this issue.Methods Here,we measured N and P concentrations of needles of different ages in two woody evergreen conifer species-white spruce(Picea glauca Voss.)and balsam fir(Abies balsamea Mill.)-to determine the effects of needle aging on nutrient resorption.Important Findings For both species,N and P concentrations were higher in newer needles than in older needles.Nutrient resorption efficiency,i.***.percentage of nutrients resorbed during senescence,also declined significantly with needle age from 73 to 22%in these two evergreen conifer species.The difference in nutrient resorp-tion between old and young needles may be attributed to the size of N and P sink tissues,which is likely to decrease with needle age.These results suggest that needle age affects the extent of N and P resorption in these two evergreen conifer species.

关键词： evergreen conifer needle age nutrient resorption Picea glauca Abies balsamea

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Distribution characteristics of available trace elements in soil from a reclaimed land in a mining area of north shaanxi,China

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International soil and water conservation Research 2013年第1期1卷 65-75页

作者： Li Zhanbin Zhang Qinling Li Peng Key Lab of Northwest water Resources and Environment Ecology of MOE Xi'an University of Technology Xi'an 710048ShaanxiP.R.China State Key Laboratory of soil Erosion and Dry-land Farming on the Lous Plateau Institute of Soil and Water ConservationChinese Academy of SciencesYangling 712100ShaanxiP.R.China Soil and Water Conservation Bureau in Shaanxi Province Xi'an 710042ShaanxiP.R.China

Through field and laboratory tests we studied the temporal and spatial variation in the soil content of four available trace elements:copper(Cu),iron(Fe),manganese(Mn)and zinc(Zn),to analyze their distribution characteristics in reclaimed mining land under different reclamation conditions.The available trace elements content varied considerably with different land reclamation patterns.Extended reclamation time was helpful for the recovery of the available trace element content in the soil,and after more than eight years of soil reclamation,the content of available trace elements was closer to or greater than that in soil under natural conditions.Various treatment measures significantly influenced the content and distribution of available trace elements in the soil,and reasonable artificial treatments,including covering the soil and growing shrubs and herbaceous plants,increased the content of available trace elements.

关键词： Available trace element Reclaimed land Reclamation time Treatment measure Mining area

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Coupling between the Grain for Green Program and a household level-based agricultural eco-economic system in Ansai,shaanxi province of China

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Journal of Arid Land 2020年第2期12卷 199-214页

作者： LI Yue WANG Jijun HAN Xiaojia GUO Mancai CHENG Simin QIAO Mei ZHAO Xiaocui Institute of soil and water conservation Northwest A&F UniversityYangling 712100China Institute of soil and water conservation Chinese Academy of Sciences and Ministry of Water ResourcesYangling 712100China

The implementation of the Grain for Green Program(GGP)has changed the development track of the agricultural eco-economic system in China.In response to the results of a lag study that investigated the coupling between the GGP and the agricultural eco-economic system in a loess hilly region,we used a structural equation model to analyze the survey data from 494 households in Ansai,a district of Yan’an City in shaanxi province of China in 2015.The model clarified the direction and intensity of the coupling between the GGP and the agricultural eco-economic system.The coupling benefits were derived through linkages between the program and various chains in the agricultural eco-economic system.The GGP,the agroecosystem of Ansai and their potential coupling effects were in a state of general coordination.The agroecosystem directly affected the coupling effect,with the standardized path coefficient of 0.87,indicating that the agroecosystem in Ansai at this stage provided basic material support for the coupling between the GGP and the agricultural eco-economic system.The direct path coefficient of agroeconomic system impacted on the coupling effect was-0.76,indicating that partial contradictions occurred between the agroeconomic system and the coupling effect.Therefore,although the current agroecosystem in Ansai should be provided sufficient agroecological resources for the benign coupling between the program and the agricultural eco-economic system,agricultural development failed to effectively transform agroecological resources into agricultural economic advantages in this region,which resulted in a relative lag in the development of the agricultural economic system.Thus,the coupling between the GGP and the agricultural eco-economic system was poor.To improve the coupling and the sustainable development of the agricultural eco-economic system in cropland retirement areas,the industrial structure needs to be diversified,the agricultural resources(including agroecological resources,agricultural economic resources and agr

关键词： Grain for Green Program agroecosystem agroeconomic system agrosocial system coupling effect household structural equation model

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Runoff-and erosion-reducing effects of vegetation on the loess hillslopes of China under concentrated flow

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International soil and water conservation Research 2022年第4期10卷 662-676页

作者： Wenzhao Guo Li Luo Hongwei Li Wenlong Wang Yun Bai State Key Laboratory of soil Erosion and Dryland Farming on the Loess Plateau Institute of Water and Soil ConservationNorthwest A&F UniversityYangling712100ShaanxiChina School of water Conservancy and Architectural Engineering Northwest A&F UniversityYangling712100ShaanxiChina Hanjiang-to-Weihe River Valley water Diversion Project Construction Co.Ltd. Xian710000ShaanxiChina Yulin University Yulin719000ShaanxiChina

Evaluating the effects of revegetation on runoff and erosion reduction is essential for studying soil and water conservation on the Loess Plateau after implementation of China's Grain for Green Project.However,quantifying the influence of revegetation on the erosion caused by concentrated runoff in extreme rainstorms is still challenging.To evaluate this influence,scouring-erosion experiments were implemented in situ on the vegetated hillslope plots(GR)and bare hillslope plots(CK).The runoffreducing effects of grass(GRR)averaged 31%,20%and 8%,and the erosion-reducing effects of grass(GER)averaged 93%,95%and 93%on the 5-plots,10-plots and 18-plots,respectively.The ratios of GRR to GER were 0.09e0.33,implying that the ability of vegetation to reduce erosion was greater than its ability to reduce runoff.The GRR and GER obviously decreased as the inflow rate increased,and the GRR decreased as the hillslope gradient increased,but there were no obvious differences in the GER between hillslope gradients.Vegetation could decrease the ability of the concentrated flow to carry and transport sediment and increase the energy consumption of the concentrated flow in response to hydraulic resistance.Vegetation also significantly reduced the degree of rill development.The degree of rill dissection on the GR(0.054e0.087 m^(2)m^(2))was lower than that on the CK(0.061e0.184 m^(2)m^(2)).Our findings provide an essential reference for ecological environment and vegetation restoration on loess hillslopes.

关键词： soil erosion Concentrated runoff China's grain for green project Vegetation Hydraulic parameters Chinese loess plateau

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Manipulated precipitation regulated carbon and phosphorus limitations of microbial metabolisms in a temperate grassland on the Loess Plateau,China

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Journal of Arid Land 2022年第10期14卷 1109-1123页

作者： HAI Xuying LI Jiwei LIU Yulin WU Jianzhao LI Jianping SHANGGUAN Zhouping DENG Lei State Key Laboratory for soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationNorthwest A&F UniversityYangling 712100China Institute of soil and water conservation Chinese Academy of Science and Ministry of Water ResourcesYangling 712100China School of Agriculture Ningxia UniversityYinchuan 750021China

Manipulated precipitation patterns can profoundly influence the metabolism of soil microorganisms.However,the responses of soil organic carbon(SOC)and nutrient turnover to microbial metabolic limitation under changing precipitation conditions remain unclear in semi-arid ecosystems.This study measured the potential activities of enzymes associated with carbon(C:β-1,4-glucosidase(BG)andβ-D-cellobiosidase(CBH)),nitrogen(N:β-1,4-N-acetylglucosaminidase(NAG)and L-leucine aminopeptidase(LAP))and phosphorus(P:alkaline phosphatase(AP))acquisition,to quantify soil microbial metabolic limitations using enzymatic stoichiometry,and then identify the implications for soil microbial metabolic limitations and carbon use efficiency(CUE)under decreased precipitation by 50%(DP)and increased precipitation by 50%(IP)in a temperate grassland.The results showed that soil C and P were the major elements limiting soil microbial metabolism in temperate grasslands.There was a strong positive dependence between microbial C and P limitations under manipulated precipitation.Microbial metabolism limitation was promoted by DP treatment but reversed by IP treatment.Moreover,CUE was inhibited by DP treatment but promoted by IP treatment.soil microbial metabolism limitation was mainly regulated by soil moisture and soil C,N,and P stoichiometry,followed by available nutrients(i.e.,NO^(-)_(3),NH^(+)_(4),and dissolved organic C)and microbial biomass(i.e.,MBC and MBN).Overall,these findings highlight the potential role of changing precipitation in regulating ecosystem C turnover by limiting microbial metabolism and CUE in temperate grassland ecosystems.

关键词： carbon use efficiency ecoenzymatic stoichiometry microbial metabolic limitations semi-arid ecosystems soil organic carbon

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Measuring flow velocity on frozen and non-frozen slopes of black soil through leading edge method

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International soil and water conservation Research 2017年第3期5卷 180-189页

作者： Chao Chen Yunyun Ban Xuefeng Wang Tingwu Lei College of water Resources and Civil Engineering China Agricultural UniversityQinghua DongluBeijing100083PR China State Key Laboratory of soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationChinese Academy of Science and Ministry of Water ResourcesYanglingShaanxi Province 712100PR China

Flow velocity is a major parameter related to hillslope hydrodynamics erosion.This study aims to measure flow velocity over frozen and non-frozen slopes through leading edge method before being calibrated with accurate flow velocity to determine the correct coefficient for convenience of flow velocity measurement.Laboratory experiments were conducted on frozen and non-frozen soil slopes with flumes involving four slope gradients of 5°,10°,15°,and 20°and three flow rates of 1,2,and 4 L/min with a flume of 6 m long and 0.1 m wide.The measurements were made with a stopwatch to record the time duration that the water flow ran over the rill segments of 2,4 and 6 m long.Accurate flow velocity was measured with electrolyte trace method,under pulse boundary condition.The leading edge and accurate flow velocities were used to determine the correction coefficient to convert the former to the latter.Results showed that the correction coefficient on frozen soil slope was 0.81 with a coefficient of determination(R2)of 0.99.The correction coefficient on non-frozen soil slope was 0.79 with R2 of 0.98.A coefficient of 0.8 was applicable to both soil surface conditions.The accurate velocities on the four frozen black soil slopes were approximately 30%,54%,71%,and 91%higher than those on non-frozen soil slopes.By contrast,the leading edge flow velocities on the frozen soil slopes were 23%,54%,67%,and 84%higher than those on non-frozen soil slopes.The flow velocities on frozen soil slopes increased with flow rate at all four slopes,but they increased from 5 to 15°before getting stabilized.Therefore,rill flow velocity can be effectively measured with leading edge method by multiplying the leading edge velocity with a correction coefficient of 0.80.This study provides a strategy to measure rill flow velocity for studies on soil erosion mechanisms.

关键词： Flow velocity Leading edge method Frozen/non-frozen soil

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