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The first high spatial resolution multi-scale daily SPI and SPEI raster dataset for drought monitoring and evaluating over China from 1979 to 2018

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Big Earth Data 2023年第3期7卷 860-885页

作者： Rongrong Zhang virgílio A.Bento Junyu Qi Feng Xu Jianjun Wu Jianxiu Qiu Jianwei Li Wei Shui Qianfeng Wang Fujian Provincial Key Laboratory of Remote Sensing of soil Erosion and Disaster Protection/College of Environmental&Safety Engineering Fuzhou UniversityFuzhouChina Instituto Dom Luiz Faculdade de CiênciasUniversidade de LisboaLisboaPortugal Earth System science Interdisciplinary Center University of MarylandCollege ParkMDUSA state Key Laboratory of Earth Surface Processes and Resource Ecology/faculty of Geographical science Beijing Normal UniversityBeijingChina Guangdong Provincial Key Laboratory of Urbanization and Geo-simulation School of Geography and PlanningSun Yat-sen UniversityGuangzhouChina College of Physics and Information Engineering Fuzhou UniversityFuzhouChina Key Lab of Spatial Data Mining&Information Sharing Ministry of Education of ChinaFuzhouChina

Standardized Precipitation Index(SPI)and Standardized Precipitation Evapotranspiration Index(SPEI),traditionally derived at a monthly scale,are widely used drought *** overcome temporalresolution limitations,we have previously developed and published a well-validated daily SPI/SPEI in situ *** having a high temporal resolution,this in situ dataset presents low spatial resolution due to the scarcity of ***,based on the China Meteorological Forcing Dataset,which is composed of data from more than 1,000 ground-based observation sites and multiple remote sensing grid meteorological dataset,we present the first high spatiotemporal-resolution daily SPI/SPEI raster datasets over *** spans from 1979 to 2018,with a spatial resolution of 0.1°×0.1°,a temporal resolution of 1-day,and the timescales of 30-,90-,and *** show that the spatial distributions of drought event characteristics detected by the daily SPI/SPEI are consistent with the monthly SPI/*** correlation between the daily value of the 12-month scale and the monthly value of SPI/SPEI is the strongest,with linear correlation,Nash-Sutcliffe coefficient,and normalized root mean square error of 0.98,0.97,and 0.04,*** daily SPI/SPEI is shown to be more sensitive to flash drought than the monthly SPI/*** improved SPI/SPEI shows high accuracy and credibility,presenting enhanced results when compared to the monthly SPI/*** total data volume is up to 150 GB,compressed to 91 GB in Network Common Data Form(NetCDF).It can be available from Figshare(https://***/10.6084/***.c.5823533)and scienceDB(https://***/10.57760/sciencedb.j00076.00103).

关键词： Drought index climate change climatic disaster Generalized Extreme value

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Yield-scaled nitrous oxide emissions from nitrogen-fertilized croplands in China: A meta-analysis of contrasting mitigation scenarios

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Pedosphere 2021年第2期31卷 231-242页

作者： Garba ALIYU Jiafa LUO Hong J.DI Deyan LIU Junji YUAN Zengming CHEN Tiehu HE Weixin DING state Key Laboratory of soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008(China) university of Chinese Academy of sciences Beijing 100049(China) AgResearch Limited Ruakura Research CentreHamilton 3240(New Zealand) faculty of Agriculture and Life sciences Lincoln UniversityLincoln 7646(New Zealand)

Nitrogen(N) losses in cropland resulting from the application of synthetic fertilizers decrease crop productivity and exacerbate environmental *** measures, such as reduction in N fertilizer application rates, can have unintentional adverse effects on crop yield. We conducted a meta-analysis of soil N_(2)O emissions from agricultural fields across China under contrasting mitigation scenarios as a novel approach to identify the most effective strategy for the mitigation of emissions of N_(2)O derived from N fertilizer use in China. Current standard agricultural practice was used as a baseline scenario(BS), and 12 potential mitigation scenarios(S1–S12) were derived from the available literature and comprised single and combinations of management scenarios that accounted for crop yield. Mitigation scenarios S6(nitrification inhibitor 3,4-dimethylpyrazole phosphate) and S11(20% reduction in N application rate plus nitrification inhibitor dicyandiamide) in maize, rice, and wheat crops led to an average 56.0% reduction in N_(2)O emissions at the national level, whereas scenario S4(nitrification inhibitor dicyandiamide) led to yield optimization, with a 14.0% increase for maize and 8.0% increase for rice as compared to the BS. Implementation of these most effective mitigation scenarios(S4, S6, and S11) might help China, as a signatory to the 2015 United Nations Framework Convention on Climate Change(Paris Agreement), to achieve a 30% reduction in N_(2)O emissions by 2030.

关键词： crop yield emission factor nitrification inhibitor nitrogen partial factor productivity N_(2)O emission yield-scaled emission

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ECOLOGICAL EFFECTS OF NITROGEN DEPOSITION ON URBAN FORESTS: AN ovERvIEW

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Frontiers of Agricultural science and Engineering 2022年第3期9卷 445-456页

作者： Enzai DU Nan XIA Yuying GUO Yuehan TIAN Binghe LI Xuejun LIU Wim DE vRIES state Key Laboratory of Earth Surface Processes and Resource Ecology Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China School of Natural Resources Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China National Academy of Agriculture Green Development Key Laboratory of Plant-Soil Interactions of Ministry of EducationCollege of Resources and Environmental SciencesChina Agricultural UniversityBeijing 100193China Wageningen university and Research Environmental ResearchPO Box 47NL-6700 AA Wageningenthe Netherlands Wageningen university and Research Environmental Systems Analysis GroupPO Box 47NL-6700 AA Wageningenthe Netherlands

The global urban area is expanding continuously,resulting in unprecedented emissions and deposition of reactive nitrogen(N)in urban ***,large knowledge gaps remain in the ecological effects of N deposition on urban forests that provide key ecosystem services for an increasing majority of city *** current understanding of the spatial patterns and ecological effects of N deposition in urban forests was synthesized based on a literature review of observational and experimental *** deposition generally increases closer to cities,resulting in an urban hotspot *** components of N deposition also shift across urban-suburban-rural gradients,showing higher ratios of ammonium to nitrate in and around urban *** ecological effects of N deposition on urban forest ecosystems are overviewed with a special focus on ecosystem N cycling,soil acidification,nutrient imbalances,soil greenhouse gas emissions,tree growth and forest productivity,and plant and soil microbial *** distinct effects of unprecedented N deposition on urban forests are discussed in comparison with the common effects in natural *** the existing research efforts,several key research needs are highlighted to fill the knowledge gaps in the ecological effects of N deposition on urban forests.

关键词： biodiversity carbon sequestration nitrogen deposition nutrient imbalance soil acidification urban forest

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Assessing soil thickness in a black soil watershed in northeast China using random forest and field observations

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International soil and Water Conservation Research 2021年第1期9卷 49-57页

作者： Shuai Zhang Gang Liu Shuli Chen Craig Rasmussen Baoyuan Liu faculty of Geographical science Beijing Normal UniversityBeijing 100875China state Key Laboratory of soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationChinese Academy of Sciences and Ministry of Water ResourcesYangling 712100China Department of Environmental science University of Arizona1177 E.Fourth StTucsonAZ 85721-0038USA

soil thickness determines the soil productivity in the black soil region of northeast China,which is important for national food *** information on the spatial variation of black soil thickness is *** this paper,we propose a model framework for spatial estimation of the black soil thickness at the watershed scale by integrating field observations,unmanned aerial vehicle variations of topography,and satellite variations of vegetation with the aid of random *** sampled 141 sample profiles over a watershed and identified the black soil thickness based on indices of the mollic *** variables were derived from a digital elevation model and vegetation variables were derived from Landsat 8 *** forest was used to determine the relationship between black soil thickness and environmental *** resulting model explained 61%of the black soil thickness spatial variation,which was more than twice that of traditional interpolation methods(ordinary kriging,universal kriging and inverse distance weighting).Topographic variables contributed the most toward explaining the thickness,followed by vegetation *** black soil thickness over the watershed had a clear catenary soil pattern,with thickest black soil in the low depositional areas and thinnest at the higher elevations that drain into the low *** proposed model framework will improve estimates of soil thickness in the region of our study.

关键词： soil thickness Random forest Black soils Northeast China soil geomorphology

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Stabilization versus decomposition in alpine ecosystems of the Northwestern Caucasus:The results of a tea bag burial experiment

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Journal of Mountain science 2018年第8期15卷 1633-1641页

作者： Tatiana G.ELUMEEvA vladimir G.ONIPCHENKO Asem A.AKHMETZHANovA Mikhail I.MAKARov Joost A.KEUSKAMP Department of Geobotany Biological FacultyLomonosov Moscow State University119234 Leninskie Gory 1/12MoscowRussia Department of General soil science Faculty of Soil ScienceLomonosov Moscow State University119234 Leninskqe Gory 1/12MoscowRussia Ecology 8:Biodiversity Group Utrecht UniversityP.O.Box 80.0563508 TB UtrechtThe Netherlands Netherlands Institute of Ecology(NIOO-KNA W) P.O.Box 596700 AB WageningenThe Netherlands

Mountainous areas exhibit highly variable decomposition rates as a result of strong local differences in climate and vegetation type. This paper describes the effect of these factors on two major determinants of the local carbon cycle: litter decomposition and carbon stabilization. In order to adequately reflect local heterogeneity, we have sampled 12 typical plant communities of the Russian Caucasus. In order to minimize confounding effects and encourage comparative studies, we have adapted the widely used tea bag index(TBI) that is typically used in areas with low decomposition. By incubating standardized tea litter for a year, we investigated whether(1) initial litter decomposition rate(k) is negatively correlated with litter stabilization(S) and(2) whether k or S exhibit correlations with altitude and other environmental conditions. Our results show that S and k are not correlated. Altitude, p H, and water content significantly influenced the stabilization factor S, while soil-freezing had no influence. In contrast, none of these factors predicted the decomposition rate k. Based on our data, we argue that collection of decomposition rates alone, as is now common practice, is not sufficient to understand carbon input to soils and can potentially lead to misleading results. Our data on community-specific decomposition and stabilization rates further constrain estimates of litter accumulation in subalpine communities and the potential effects of climate change.

关键词： Litter decomposition Alpine communities Tea bag index Carbon cycle

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Dry-season sources of riverine sediment from the tropical mixed urban-agricultural watershed of the Mun River Basin in northeastern Thailand

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International Journal of Sediment Research 2023年第2期38卷 240-252页

作者： Arika Bridhikitti Thayukorn Prabamroong Gaohuan Liu Environmental Engineering and Disaster Management Program School of Interdisciplinary Studies Mahidol University Kanchanaburi Campus Earth science Research Center Mahidol University Kanchanaburi Campus faculty of Environment and Resource Studies Mahasarakham University state Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences

Northeastern(NE) Thailand is well recognized as the land for rice cropping and consequently, it is potentially contaminated with chemicals from soil fertilization, pest/weed control, and urban *** Mun River basin in NE Thailand principally is comprised of rice paddies and sedimentation in the river has been pronounced, but the studies on sediment source identification are limited. The current study aims to identify sediment sources in the Mun River basin and discuss possible impacts on ecosystems attributed to exposure to polluted sediment. The assessment relies upon physicochemical properties and heavy metal contents(iron(Fe), manganese(Mn), copper(Cu), chromium(Cr), nickel(Ni),and Zinc(Zn)) in the fine-grained sediment(ver basin and the Chi River in the dry season of 2020-2021. The findings revealed that the heavy metals in the sediment had not accumulated to levels of concern. Most sediment was from natural sources, including Fe-and Mn-rich sediment, Cr-dominant sediment, and Ni-and Cu-rich sediment. Fe-and Zn-rich sediment was, however, found in the urban watershed of Lam Ta Klong, and it could originate from mixed urban sources. Ferich sediment was predominant in the Mun River basin, which and could be a significant sink and source of toxic elements from agricultural and urban discharges. It is suggested that the toxic compounds in the sediment should be consistently monitored, whereas ecological and health risk assessment should be focused on the mobile forms.

关键词： Sediment Heavy metals Mun River Lower Mekong River Agriculture

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Efficiency test of modeled empirical equations in predicting soil loss from ephemeral gully erosion around Mubi,Northeast Nigeria

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International soil and Water Conservation Research 2016年第1期4卷 12-19页

作者： Ijasini John Tekwa Abubakar Musa Kundiri Alhaji Maigana Chiroma Department of Agricultural Technology The Federal PolytechnicP.M.B 35MubiAdamawa StateNigeria Department of soil science Faculty of AgricultureFederal University DutseP.M.B 7156DutseJigawa StateNigeria Department of soil science Faculty of AgricultureUniversity of MaiduguriP.M.B 1069MaiduguriBorno StateNigeria

A field study was carried out to assess soil loss from ephemeral gully(EG)erosion at 6 different locations(Digil,vimtim,Muvur,Gella,Lamorde and Madanya)around the Mubi area between April,2008 and October,*** location consisted of 3 watershed sites from where data was *** shape,land use,and conservation practices were noted,while EG length,width,and depth were ***-chemical properties of the soils were studied in the field and *** loss was both measured and predicted using modeled empirical *** showed that the soils are heterogeneous and lying on flat to hilly topographies with few grasses,shrubs and tree *** soils comprised of sand fractions that predominated the texture,with considerable silt and clay *** empirical soil loss was generally related with the measured soil loss and the predictions were widely reliable at all sites,regardless of *** measured and empirical aggregate soil loss were more related in terms of volume of soil loss(vSL)(r^(2)=0.93)and mass of soil loss(MSL)(r^(2)=0.92),than area of soil loss(ASL)(r^(2)=0.27).The empirical estimates of vSL and MSL were consistently higher at Muvur(less vegetation)and lower at Madanya and Gella(denser vegetations)in both *** maximum efficiency(M_(se))of the empirical equation in predicting ASL was between 1.41(Digil)and 89.07(Lamorde),while the M_(se) was higher at Madanya(2.56)and lowest at vimtim(15.66)in terms of vSL prediction *** M_(se) also ranged from 1.84(Madanya)to 15.74(vimtim)in respect of MSL *** results led to the recommendation that soil conservationists,farmers,private and/or government agencies should implement the empirical model in erosion studies around Mubi area.

关键词： Empirical model soil loss Prediction efficiency Ephemeral gully erosion Mubi Northeast Nigeria

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高应力地下交叉洞室爆破诱发掉块的微震活动及震源机制研究

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Journal of Central South university 2023年第2期30卷 542-554页

作者：赵金帅江权裴书锋陈炳瑞徐鼎平宋磊博 faculty of Civil Engineering and Mechanics Jiangsu UniversityZhenjiang 212013China state Key Laboratory of Geomechanics and Geotechnical Engineering(Institute of Rock and soil Mechanics Chinese Academy of Sciences)Wuhan 430071China North China university of Water Resources and Electric Power Zhengzhou 450046China faculty of Civil Engineering Shaoxing UniversityShaoxing 312000China

岩体掉块是在地下洞室开挖过程中容易遇到的破坏灾害之一。为客观评价爆破开挖引起的地下交叉洞室岩体掉块的微震活动及震源机制,在白鹤滩水电站母线洞安装了6个单轴加速度计和8个单轴检波器,开展原位微震监测试验。在时域上,生产爆破... 详细信息

岩体掉块是在地下洞室开挖过程中容易遇到的破坏灾害之一。为客观评价爆破开挖引起的地下交叉洞室岩体掉块的微震活动及震源机制,在白鹤滩水电站母线洞安装了6个单轴加速度计和8个单轴检波器,开展原位微震监测试验。在时域上,生产爆破的微震活动响应表明,爆破后3 h内,微震活动处于活跃阶段。在空间域上,随着工作面的推进,开挖区周围的应力集中分布,岩体的破坏和劣化逐渐加剧。微震事件的活动区域与应力集中区域一致。基于矩张量反演法分析破裂机理可知,地下交叉洞室岩体掉块的破裂机理以拉张断裂为主。研究结果可为类似地下洞室围岩的稳定性分析、爆破开挖及支护优化等问题的重新思考提供重要参考依据。

关键词：掉块微震监测爆破开挖微震活动特性震源机制

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Slope failure simulations with MPM

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Journal of Hydrodynamics 2017年第3期29卷 445-451页

作者： Philip J.vardon Bin Wang Michael A.Hicks Geo-Engineering Section Faculty of Civil Engineering and GeosciencesDelft University of Technology state Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of Sciences

The simulation of slope failures,including both failure initiation and development,has been modelled using the material point method（MPM）.Numerical case studies involving various slope angles,heterogeneity and rainfall infiltration are *** is demonstrated that,by utilising a constitutive model which encompasses,in a simplified manner,both pre-and post-failure behaviour,the material point method is able to simulate commonly observed failure *** is a step towards being able to better quantify slope failure consequence and risk.

关键词： Heterogeneity material point method(MPM) rainfall-induced slope failure strain softening

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Efficient Priority-Flood depression filling in raster digital elevation models

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International Journal of Digital Earth 2019年第4期12卷 415-427页

作者： Hongqiang Wei Guiyun Zhou Suhua Fu Center for Information Geoscience University of Electronic Science and Technology of ChinaChengduPeople’s Republic of China School of Resources and Environment University of Electronic Science and Technology of ChinaChengduPeople’s Republic of China state Key Laboratory of soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationChinese Academy of SciencesYanglingPeople’s Republic of China faculty of Geographical science Beijing Normal UniversityBeijingPeople’s Republic of China

Depressions in raster digital elevation models(DEM)present a challenge for extracting hydrological *** are commonly filled before subsequent algorithms are further *** existing algorithms for filling depressions,the Priority-Flood algorithm runs the *** this study,we propose an improved variant over the fastest existing sequential variant of the Priority-Flood algorithm for filling depressions in floating-point *** proposed variant introduces a series of improvements and greatly reduces the number of cells that need to be processed by the priority queue(PQ),the key data structure used in the *** proposed variant is evaluated based on statistics from 30 *** average,our proposed variant reduces the number of cells processed by the PQ by around 70%.The speed-up ratios of our proposed variant over the existing fastest variant of the Priority-Flood algorithm range from 31%to 52%,with an average of 45%.The proposed variant can be used to fill depressions in large DEMs in much less time and in the parallel implementation of the Priority-Flood algorithm to further reduce the running time for processing huge DEMs that cannot be dealt with easily on single computers.

关键词： Depression filling DEM drainage network

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