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Radar Quantitative Precipitation Estimation Based on the Gated Recurrent Unit Neural Network and Echo-Top Data

Advances in Atmospheric Sciences 2023年第6期40卷 1043-1057页

作者： Haibo ZOU Shanshan WU Miaoxia TIAN key laboratory of {2. lake wetland and watershed research of Ministry of Education&School of Geography and Environmental Science Jiangxi Normal UniversityNanchang 330022China Meteorological Sciences Institute of Jiangxi Province Nanchang 330046China key laboratory of Natural Disaster Monitoring Early Warning and Assessment of Jiangxi ProvinceNanchang 330022China Jiangxi Climate Center Nanchang 330046China

The Gated Recurrent Unit(GRU) neural network has great potential in estimating and predicting a variable. In addition to radar reflectivity(Z), radar echo-top height(ET) is also a good indicator of rainfall rate(R). In this study, we propose a new method, GRU_Z-ET, by introducing Z and ET as two independent variables into the GRU neural network to conduct the quantitative single-polarization radar precipitation estimation. The performance of GRU_Z-ET is compared with that of the other three methods in three heavy rainfall cases in China during 2.18, namely, the traditional Z-R relationship(Z=300R1.4), the optimal Z-R relationship(Z=79R1.68) and the GRU neural network with only Z as the independent input variable(GRU_Z). The results indicate that the GRU_Z-ET performs the best, while the traditional Z-R relationship performs the worst. The performances of the rest two methods are *** further evaluate the performance of the GRU_Z-ET, 2.0 rainfall events with 2.882.total samples during May–July of 2.18 are used for statistical analysis. Results demonstrate that the spatial correlation coefficients, threat scores and probability of detection between the observed and estimated precipitation are the largest for the GRU_Z-ET and the smallest for the traditional Z-R relationship, and the root mean square error is just the opposite. In addition, these statistics of GRU_Z are similar to those of optimal Z-R relationship. Thus, it can be concluded that the performance of the GRU_ZET is the best in the four methods for the quantitative precipitation estimation.

关键词： quantitative precipitation estimation Gated Recurrent Unit neural network Z-R relationship echo-top height

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Remote Sensing and GIS Application in the Detection of Environmental Degradation Indicators

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Geo-Spatial Information Science 2011年第1期14卷 39-47页

作者： HadeelA S Mushtak T Jabbar CHEN Xiaoling State key laboratory of Information Engineering in Surveying Mapping and Remote Sensing Wuhan University 129 Luoyu Road Wuhan 430079. China Department of Soil and Water College of Agriculture University of Basrah (Iraq) key laboratory of {2. lake wetland and watershed research Ministry of Education Jiangxi Normal UniversityNanchang 330022. China

The main aim of this research is to highlight the environment change indicators during the last 2. years in a representative area of the southern part of Iraq （Basrah Province was taken as a case） to understand the main causes which led to widespread environment degradation phenomena using a 1：2.0000 mapping scale. Remote sensing and GIS＇s software were used to classify Landsat TM in 1990 and Landsat ETM＋ in 2.03 imagery into five land use and land cover （LULC） classes： vegetation land, sand land, urban area, unused land, and water bodies. Supervised classification and Normalized Difference Vegetation Index （NDVI）, Normalized Difference Build-up Index （NDBI）, Normalized Difference Water Index （NDWI）, Normalized Difference Salinity Index （NDSI）, and Topsoil Grain Size Index （GSI） were adopted in this research and used respectively to retrieve its class boundary. The results showed a clear deterioration in vegetative cover （514.9 km2. and an increase of sand dune accumulations （438.6 km2., accounting for 10.1, and 10.6 percent, respectively, of the total study area. In addition, a decrease in the water bodies＇ area was detected （2.8.9 kin2.. Sand area accumulations had increased in the total study area, with an annual increasing expansion rate of （33.7 km2.· yr^-1） during the thirteen years covered by the study. It is therefore imperative that Iraqi government undertake a series of prudent actions now that will enable to be in the best possible position when the current environmental crisis ultimately passes.

关键词： environment degradation LULC RS GIS classification indices

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Major Elements in Soils Along a 2.8-km Altitudinal Gradient on the Tibetan Plateau,China

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Pedosphere 2016年第6期26卷 895-903页

作者： WANG Zhaofeng Alfred E.HARTEMINK ZHANG Yili ZHANG Hua DING Mingjun key laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences University of Wisconsin-Madison Department of Soil ScienceFD Hole Soils Lab key laboratory of {2. lake and watershed Resarch Ministry of EducationJiangxi Normal University

There are a series of special mountain soils on the Tibetan Plateau of China in an alpine environment for the high altitude. However, very few studies have focused on major soil elements in relation to soil formation in this area. Aluminum （Al）, iron （Fe）, calcium （Ca）, sodium （Na）, potassium （K） and magnesium （Mg） contents of 2.7 topsoil samples covering a 2.8-km altitudinal gradient in uncultivated areas along the Qinghai-Tibet Railway of China were measured using inductively coupled plasma atomic emission spectroscopy. The spatial distribution of the elements and its relationship to the parent rocks and climatic parameters were analyzed. Soils along the gradient are derived from a range of parent materials, but most are less than 30 cm deep with little development （Cambisols）. Soil Al, Fe and Mg contents showed a decreasing trend from the start station （Xining Station） to end station （Lhasa Station） of the Qinghai-Tibet Railway, whereas soil K and Na contents were relative stable from Xining Station to the Kunlun Mountains and then increased gradually. Soil Ca content was lower in the southern part of the Tanggula Mountains. The major soil element contents clearly reflected the parent rock and climatic influences. Soils with higher Ca content appeared in areas with Ca-Mg carbonate rocks, soils with higher Al were found in areas with silicate-rich and high-Al silicate clastic rocks and silicate-rich aluminosilicate loose sediments. Soils with higher K and Na contents appeared in areas with high-K, high-Na and silicate-rich aluminosilicate rocks. Soil Na and K contents were affected by temperature, whereas the contents of Mg, Fe, Ca and Al were more affected by precipitation. Soil Na and K contents increased with increasing temperatures, whereas the contents of Mg, Fe, Ca and Al decreased with increasing precipitation. This analysis provides a relationship between soil properties and rapidly changing environmental conditions. The data can be used to investigate the

关键词： alpine environment climate mountain soil parent material precipitation temperature pedogenesis soil formation

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Incomplete lineage sorting and introgression in the diversification of Chinese spot-billed ducks and mallards

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Current Zoology 2019年第5期65卷 589-597页

作者： Wenjuan WANG Yafang WANG Fumin Lei Yang LIU Haitao WANG Jiakuan Chen Jiangxi Province key laboratory of {2. Ecosystem Change and Biodiversity Center for Watershed EcologyInstitute of Life Science and School of Life ScienceNanchang UniversityNanchangChina lnstitute of Biodiversity Science Fudan UniversityShanghaiChina key laboratory of {2. lake Environment and Resource Utilization Ministry of EducationNanchang UniversityNanchangChina National Ecosystem research Station of Jiangxi poyang {2. wetland NanchangChina key laboratory of Zoological Systematics and Evolution Institute of ZoologyChinese Academy of SciencesBeijingChina State key laboratory of Biocontrol Department of Ecology/School of Life SciencesSun Yat-sen UniversityGuangzhouChina Jilin Provincial Engineering laboratory of Avian Ecology and Conservation Genetics School of Life SciencesNortheast Normal UniversityChangchunChina

Incomplete lineage sorting and introgression are 2.major and nonexclusive causes of specieslevel *** between these 2.processes is notoriously difficult because they can generate similar genetic *** studies have suggested that 2.closely related duck species,the Chinese spot-billed duck Anas zonorhyncha and the mallard *** polyphyletically ***,we utilized a wide geographical sampling,multilocus data and a coalescent-based model to revisit this *** study confirms the finding that Chinese spot-billed ducks and Mallards are not *** was no apparent interspecific differentiation across loci except those at the mitochondrial DNA(mtDNA)control region and the Z chromosome(CHD1Z).Based on an isolation-with-migration model and the geographical distribution of lineages,we suggest that both introgression and incomplete lineage sorting might contribute to the observed non-monophyly of the 2.closely related duck *** mtDNA introgression was asymmetric,with high gene flow from Chinese spot-billed ducks to Mallards and negligible gene flow in the opposite *** that the 2.duck species are phenotypically distinctive but weakly genetically differentiated,future work based on genomescale data is necessary to uncover genomic regions that are involved in divergence,and this work may provide further insights into the evolutionary histories of the 2.species and other waterfowls.

关键词： asymmetric introgression incomplete lineage sorting non-monophyly the Mallard complex Z chromosome

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Testing mechanisms underlying elevational patterns of lakeshore plant community assembly in poyang lake, China

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Journal of Plant Ecology 2019年第3期12卷 438-447页

作者： Zhichun Lan Yasong Chen Lei Li Feng Li Binsong Jin Jiakuan Chen Jiangxi Province key laboratory of {2. Ecosystem Change and Biodiversity Center for Watershed EcologyInstitute of Life ScienceSchool of Life SciencesNanchang UniversityNanchang 330031China Coastal Ecosystems research Station of the Yangtze River Estuary Ministry of Education Key Laboratory for Biodiversity Science and Ecological EngineeringSchool of Life SciencesFudan UniversityShanghai 200438China key laboratory of {2. Ecology and Geographical Environment Monitoring NASGNanchang 330029China key laboratory of {2. lake Environment and Resource Utilization Ministry of EducationNanchang UniversityNanchang 330031China National Ecosystem research Station of Jiangxi poyang {2. wetland Nanchang 330038China key laboratory of Agro-ecological Processes in Subtropical Region Institute of Subtropical AgricultureChinese Academy of SciencesChangsha 410125China

Aims Plant community assembly in wetlands usually changes with eleva-tion gradients,which may be due to the direct effect of flooding and indirect effects such as changes in soil properties and ***,the respective importance of each factor remains to be *** We investigated patterns of plant diversity,community biomass and soil properties along an elevation gradient of a lakeshore meadow at {2. lake,*** Findings(i)With increasing elevation,species richness and Simpson diver-sity index *** aboveground biomass(AGB)and below-ground biomass(BGB)increased with elevation,however,the BGB/AGB ratio also increased,which suggests a significant effect of belowground competition.(ii)Soil N content and soil N:P ratio increased,whereas soil pH decreased with *** soil properties showed no significant response.(iii)Structural equa-tion modeling showed that variation of plant diversity was mainly explained by ***,intensified belowground competition seems to be the primary mechanism causing lower plant diversity at higher elevations.(iv)These findings were further supported by the observed greater response ratio of N and P storage in plant commu-nities than the response ratio of soil N and P content to elevation,suggesting that soil nutrient limitation and belowground nutrient competition increased with *** study has important implications to wetland management and biodiversity conserva-tion under environmental change(*** in flooding regimes,eutrophication).

关键词： belowground competition aboveground competition flooding tolerance nutrient limitation biomass allocation

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Multifractal process of runoff fluctuation of the Kaidu River in Xinjiang, China

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research in Cold and Arid Regions 2018年第3期10卷 232-239页

作者： Shuang Qing Liu Zu Han Liu Wei Guo Wang Yue Ping Lu Xiao Liang Zhu Bin Guo School of Information Engineering Nanchang Institute of Technology key laboratory of the Education Ministry for {2. lake wetland and watershed research Jiangxi Normal University research Center for East-West Cooperation in China East China Normal University

Based on the hydrological data in the headwater region of the Kaidu River during 1972.2.11, the multifractal process of runoff fluctuation was analyzed. Results indicated that, in the past 40 years, the overall runoff of the Kaidu River in Xinjiang has shown significant multifractal behavior. Its singular curve 1nχq（ε）-1n（ε） verified a favorable scale invariance over the entire time scale, r（q）-q proved that evolution of the runoff time series presented multifractal characteristics. Moreover, the multifractal spectrumf（α）-α curve was hooklike leftward which indicated that, compared to relatively large runoff events. And △f〈0 indicated that these relatively small events took the leading role; B〈0 explained the Kaidu River＇s daily-runoff ascending tendency presented during 1972.2.11. Besides that, the multifractal behavior of the Kaidu River＇s runoff variability over four decades was also analyzed. Generally speaking, by decades, their four corresponding spectrum variations were not noticeable. These △α values showed larger runoff events occupied the leading position with some local values falling. During the 1970s to the 1990s, △f〈0 illustrated the probability of the daily runoff at the lowest point is always larger than that of the highest during three continuous decades. At the beginning of the 2. st century, for △f〉0 the trend presented was contrary from the 1970s to the 1990s. B values suggested an overall trend of increases during 1972.2.11. Until the 2. st century, the runoff with a slightly descending tendency on the whole explained these relatively large runoff events taking the leading role for the Kaidu River; but sometimes, some small events also played the dominant role.

关键词： multifractal runoff Kaidu River decadal scale

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Local temperature and El Niño Southern Oscillation influence migration phenology of East Asian migratory waterbirds wintering in poyang,China

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Integrative Zoology 2017年第4期12卷 303-317页

作者： Fei XU Guanhua LIU Yali SI Ministry of Education key laboratory for Earth System Modeling Department of Earth System ScienceTsinghua UniversityBeijingChina Jiangxi poyang lake National Nature Reserve Authority Jiangxi Poyang Lake Wetland Ecosystem National Research StationNanchangChina Resource Ecology Group Wageningen UniversityWageningenthe Netherlands Center for Tropical research Institute of the Environment and SustainabilityUniversity of CaliforniaLos AngelesCaliforniaUSA

Temperature is a critical factor influencing avian phenology,due to its direct impact on food and water *** previous studies have focused on the timing of spring migration and the arrival of birds at breeding grounds along the European and American flyways;little is known about migration ecology at the wintering sites along the Asian *** linear regression models,this study investigates how local temperature variation and EI Niño Southern Oscillation(ENSO)influences the arrival and departure timing of 9 waterbird species breeding in Mongolia or Siberia and overwintering in poyang,China from 2.02.to *** mainly arrive at poyang in October and depart for their breeding sites in *** of the 9 species,6 show a strong negative relationship between departure time and overwintering temperature in *** dates also show a negative association with overwintering ENSO and March ENSO for two *** local and large-scale climate indices show no influence on the arrival timing of *** suggest that birds react to the annual variation of overwintering temperature:an earlier departure of waterbirds is facilitated by a warmer overwintering period and vice *** long-term accumulated temperature effect is more pronounced than ENSO and the short-term local temperature *** findings could help quantify the potential impact of global warming on waterbirds.

关键词： annual temperature variation arrival and departure time ENSO local accumulated temperature overwintering birds

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Assessing effects of land use and land cover changes on hydrological processes and sediment yield in the Xunwu River watershed, Jiangxi Province, China

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Frontiers of Earth Science 2022年第3期16卷 819-833页

作者： Guihua LIU Britta SCHMALZ Qi ZHANG Shuhua QI Lichao ZHANG Shiyu LIU School of Geography and Environment Key Laboratory of Poyang Lake Wetland and Watershed Research(Ministry of Education)Jiangxi Normal UniversityNanchang 330022China Department of Civil and Environmental Engineering Key Laboratory of Engineering Hydrology and Water ManagementTechnical University of DarmstadtDarmstadt 64287Germany key laboratory of {2. Geographic Sciences Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008China College of Land Resources and Environment Jiangxi Agricultural UniversityNanchang 330045China Jiangxi key laboratory of Soil Erosion and Prevention Jiangxi Institute of Soil and Water ConservationNanchang 330029China

The effects of land use and land cover changes on hydrological processes and sediment yield are important issues in regional *** Xunwu River catchment located in the red soil hilly region of southern China has experienced drastic land use changes in the past 30 years,with orchard increases of approximately 42.and forest decreases of approximately 40%.These changes have resulted in some alterations of runoff and sediment *** study aims to evaluate effects of land use/land cover on runoff and sediment yield in the Xunwu River *** SWAT model(Soil and Water Assessment Tool)was used for runoff and sediment simulation,and the results met the requirements of the model acceptance based on evaluation statistics of R^(2.(the coefficient of determination),PBIAS(percent bias),and NSE(Nash-Sutcliffe efficiency).Four land use scenarios representing the gradual expansion of orchards in the past 2. years were developed for assessment of hydrological processes and sediment yield *** a result,both runoff and sediment yield were changed insignificantly with decrease rates of 1.84%and 5.2.%,*** addition,surface runoff accounts for the largest share of the runoff components,but the lateral flow changed more than other runoff components with a decrease rate of 10.96%.The results show that orchard expansion does not reveal severe water and soil *** study can contribute to the rational utilization of land and water resources in the red soil hilly area of southern Jiangxi Province.

关键词： land use change orchard expansion red soil hilly region SWAT runoff sediment

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Spatio-temporal variation of spring phenology in Tibetan Plateau and its linkage to climate change from 1982.to 2.12

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Journal of Mountain Science 2016年第1期13卷 83-94页

作者： DING Ming-jun LI Lan-hui NIE Yong CHEN Qian ZHANG Yi-li key laboratory of {2. lake wetland and watershed research Ministry of Education and School of Geography and EnvironmentJiangxi Normal UniversityNanchang 330022China key laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of SciencesBeijing 100101China Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China

The influence of climate change on vegetation phenology is a heated issue in current climate change *** used GIMMS-3g NDVI data to detect the spatio-temporal dynamics of the start of the growing season(SGS) over the Tibetan Plateau(TP) from 1982.to 2.12.and to analyze its relationship with temperature and *** significant trend was observed in the SGS at the regional scale during the study period(R^2.= 0.03,P = 0.352..However,there were three time periods(1982.1999,1999-2.08 and 2.08-2.12. with identifiable,distinctly different *** with a significant advancing trend were mainly scattered throughout the humid and semi-humid areas,whereas the regions with a significant delaying trend were mostly distributed throughout the semi-arid *** analysis showed that the response of the SGS to climate change varies *** SGS was significantly correlated with the spring temperature and the start of the thermal growth season(STGS) in the relatively humid *** increasing aridity,theimportance of the spring temperature for the SGS gradually ***,the influences of precipitation and winter temperature on the SGS were complicated across the plateau.

关键词： Spring phenology Spatial pattern Temporal variation Climate change CorrelationTibetan Plateau (TP)

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Processes and events in the center: a taxi trajectory-based approach to detecting traffic congestion and analyzing its causes

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International Journal of Digital Earth 2023年第1期16卷 509-531页

作者： Yufeng He Barbara Hofer Yehua Sheng Yue Yin Hui Lin key laboratory of {2. lake wetland and watershed research Ministry of EducationJiangxi Normal UniversityNanchangPeople’s Republic of China School of Geography and Environment Jiangxi Normal UniversityNanchangPeople’s Republic of China Department of Geoinformatics–Z_GIS University of SalzburgSalzburgAustria School of Geography Nanjing Normal UniversityNanjingPeople’s Republic of China

A novel approach is introduced for the detection of the location and direction of traffic congestion using GPS data from *** approach uses a dynamic model that conceptualizes events,processes,and *** states are the locations of the taxis,the processes are the motion of taxis,and the events are *** model is implemented as a graph database,which represents the relationships between states,events,processes,and things(such as points of interest and road grid).Algorithms for constructing and updating the relationships and taxi behaviors dynamic retrieval method in Neo4j are presented and are used to demonstrate the capabilities in dynamic expression and *** implementation of Shanghai in 2.15finally demonstrated the ability of congestion direction detection and the cause searching of traffic congestion.

关键词： VGE Spatio-temporal dynamics geographic processes traffic congestion trajectory

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