检索结果-南通市图书馆

Spatiotemporal event detection: a review

International Journal of Digital Earth 2020年第12期13卷 1339-1365页

作者： Manzhu Yu Myra Bambacus Guido Cervone Keith Clarke Daniel Duffy Qunying Huang Jing Li Wenwen Li Zhenlong Li Qian Liu Bernd Resch Jingchao Yang Chaowei Yang Department of geography Pennsylvania State UniversityUniversity ParkPAUSA NASA Goddard Space Flight Center NASA Goddard Space Flight CenterGreenbeltMDUSA Department of geography University of California-Santa BarbaraSanta BarbaraCAUSA Department of geography University of Wisconsin-MadisonMadisonWIUSA Department of geography and the Environment University of DenverDenverCOUSA School of Geographical Sciences and Urban Planning Arizona State UniversityTempeAZUSA Department of geography University of South CarolinaColumbiaSCUSA NSF Spatiotemporal Innovation Center&dept.of geography and GeoInformation Science George Mason UniversityFairfaxVAUSA Department of Geoinformatics University of SalzburgKapitelgasseSalzburgAustria Center for Geographic Analysis Harvard UniversityBostonMAUSA

The advancements of sensing technologies,including remote sensing,in situ sensing,social sensing,and health sensing,have tremendously improved our capability to observe and record natural and social phenomena,such as natural disasters,presidential elections,and infectious *** observations have provided an unprecedented opportunity to better understand and respond to the spatiotemporal dynamics of the environment,urban settings,health and disease propagation,business decisions,and crisis and *** event detection serves as a gateway to enable a better understanding by detecting events that represent the abnormal status of relevant *** paper reviews the literature for different sensing capabilities,spatiotemporal event extraction methods,and categories of applications for the detected *** novelty of this review is to revisit the definition and requirements of event detection and to layout the overall workflow(from sensing and event extraction methods to the operations and decision-supporting processes based on the extracted events)as an agenda for future event detection *** is presented on the current challenges to this research agenda,and future directions are discussed for conducting spatiotemporal event detection in the era of big data,advanced sensing,and artificial intelligence.

关键词： GeoAI geography and geoscience human dynamics digital earth computational challenges cloud computing internet of things

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applying a support vector model to assess land cover changes in the Uvs Lake Basin ecoregion in Mongolia

引用

Information Processing in Agriculture 2019年第1期6卷 158-169页

作者： Buyan-Erdene Jamsran Chinsu Lin Ishgaldan Byambakhuu Jamsran Raash Khaulenbek Akhmadi Department of Forestry and Natural Resources National Chiayi University300 University Rd.ChiayiChiayi 60004TaiwanChina Department of Environment and Forest Engineering School of Engineering and Applied SciencesNational University of MongoliaMongolia Uvs Lake Basin Projected Area Administration Office Uvs ProvinceMongolia Head of Division for Desertification Study Institute of Geography and GeoecologyMongolian Academy of SciencesMongolia

The Uvs Lake Basin in western Mongolia is a natural world heritage site and is known for its diversity in landscape and ***,investigative research has shown that the protected pristine ecotone is suffering land degradation due to global *** order to obtain evidence of the changes over a long-term time scale,serial multi-temporal Landsat images obtained between 1995 and 2015 were used to classify land cover and land cover changes over the Basin ecoregion using a machine learning classification technique,support vector *** showed that the forest land area in 1995 was 1888.48 km^2 which was equivalent to 7.48%of the total area of the study *** forest area showed considerable decrease by 301.36 km^2 during the first decade(1995–2004)and 155.81 km^2 during second decade(2004–2015).A total of 457.17 km^2 or 24.21%of the forest land has been developed,most being changed into *** major driver of such changes was illegal logging,forest fire,and pest *** grassland was changed primarily into bare land during the two *** area of glacier was decreased and primarily changed into water *** contrast,the area of sand in the Basin ecoregion increased dramatically from 65.20 km^2 in 1995 to 318.33 km^2 in 2015 the increase being mostly from the transition of bare *** summary,the drivers of the significant decrease of greenness coverage and increase of sand/bare land areas were the interaction of complicated disturbances in both anthropogenic and natural factors,in which logging,grazing,wind erosion,and global warming were the key causes.

关键词： Land suppression Soil degradation Forest reduction Change analysis Landscape ecology

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

STRATIGRAPHIC AND GEOCHRONOLOGIC ANALYSES OF THE QUATERNARY DEPOSITS IN THE THREE-LAKE REGION OF QAIDAM BASIN

引用

Science China Chemistry 1991年第8期34卷 987-1006页

作者：刘泽纯汪永进杨藩周翥虹 dept. of geography Nanjing Normal University Institute of Oil Exploration Qinghai Oil Bureau

The Qaidam Basin is a larger sedimentary basin in western China where the thickness of the Quaternary deposits is in the range of 2000-3000 m at its subsiding center. This paper first dates palaeomagnetically the cores obtained from the five continuously sampled intervals and those from a typical profile, determineds the age of the index fossil zones, and calculates the deposition rates for the varve deposits based on the sedimentological analysis. As a result, we can calculate the ages of the various characteristic beds (including fossil zones, seismic reflection beds, and marker layers of electrical properties) for any given borehole-section when it was divided into facies, and check the validity of the chronology. According to all those studies, the stratigraphic and geochronologic analysis program of the Quaternary deposits in the Qaidam Basin has permitted a detailed discussion to be made in this paper.

关键词： mudstone facies sedimentary Quaternary stratigraphic fossil borehole shallow sandstone environments

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Community-based scenario modelling and disaster risk assessment of urban rainstorm waterlogging

引用

Journal of Geographical Sciences 2011年第2期21卷 274-284页

作者： YIN Zhan'e YIN Jie XU Shiyuan WEN Jiahong geography dept. of Shanghai Normal University Shanghai 200234 China geography dept. of East China Normal University Shanghai 200062 China

Scenario modelling and the risk assessment of natural disasters is one of the hotspots in disaster research. However, up until now, urban natural disaster risk assessments lack common procedures and programmes. This paper selects rainstorm waterlogging as a disaster to research, which is one of the most frequently occurring hazards for most cities in China. As an example, we used a small-scale integrated methodology to assess risks relating to rainstorm waterlogging hazards in the Jing＇an District of Shanghai. Based on the basic concept of disaster risk, this paper applies scenario modelling to express the risk of small-scale urban rainstorm waterlogging disasters in different return periods. Through this analysis of vulnerability and exposure, we simulate different disaster scenarios and propose a comprehensive analysis method and procedure for small-scale urban storm waterlogging disaster risk assessments. A grid-based Geographical Information System （GIS） approach, including an urban terrain model, an urban rainfall model and an urban drainage model, was applied to simulate inundation area and depth. Stage-damage curves for residential buildings and contents were then generated by the loss data of waterlogging from field surveys, which were further applied to analyse vulnerability, exposure and loss assessment. Finally, the exceedance probability curve for disaster damage was constructed using the damage of each simulated event and the respective exceedance probabilities. A framework was also developed for coupling the waterlogging risk with the risk planning and management through the exceedance probability curve and annual average waterlogging loss. This is a new exploration for small-scale urban natural disaster scenario simulation and risk assessment.

关键词： scenario modelling small-scale rainstorm waterlogging disaster risk assessment Shanghai

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Spatiotemporal variation in snow cover and its effects on grassland phenology on the Mongolian Plateau

引用

Journal of Arid Land 2021年第4期13卷 332-349页

作者： SA Chula MENG Fanhao LUO Min LI Chenhao WANG Mulan ADIYA Saruulzaya BAO Yuhai College of Geographical Science Inner Mongolia Normal UniversityHohhot 010022China Inner Mongolia Key Laboratory of Remote Sensing and Geographic Information System Inner Mongolia Normal UniversityHohhot 010022China Institute of geography and geoecology Mongolian Academy of ScienceUlaanbaatar 15170Mongolia

Snow cover is an important water source for vegetation growth in arid and semi-arid areas,and grassland phenology provides valuable information on the response of terrestrial ecosystems to climate *** Mongolian Plateau features both abundant snow cover resources and typical grassland *** recent years,with the intensification of global climate change,the snow cover on the Mongolian Plateau has changed correspondingly,with resulting effects on vegetation *** this study,using MOD10A1 snow cover data and MOD13A1 Normalized Difference Vegetation Index(NDVI)data combined with remote sensing(RS)and geographic information system(GIS)techniques,we analyzed the spatiotemporal changes in snow cover and grassland phenology on the Mongolian Plateau from 2001 to *** correlation analysis and grey relation analysis were used to determine the influence of snow cover parameters(snow cover fraction(SCF),snow cover duration(SCD),snow cover onset date(SCOD),and snow cover end date(SCED))on different types of grassland *** results showed wide snow cover areas,an early start time,a late end time,and a long duration of snow cover over the northern Mongolian ***,a late start,an early end,and a short duration were observed for grassland phenology,but the southern area showed the opposite *** SCF decreased at an annual rate of 0.33%.The SCD was shortened at an annual rate of 0.57 *** SCOD and SCED in more than half of the study area advanced at annual rates of 5.33 and 5.74 DOY(day of year),*** grassland phenology,the start of the growing season(SOS)advanced at an annual rate of 0.03 DOY,the end of the growing season(EOS)was delayed at an annual rate of 0.14 DOY,and the length of the growing season(LOS)was prolonged at an annual rate of 0.17 *** SCF,SCD,and SCED in the snow season were significantly positively correlated with the SOS and negatively correlated with the EOS and *** SCOD was significantly negative

关键词： snow cover fraction snow cover phenology vegetation phenology grey relation grade climate change Mongolian Plateau

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Spatial Dynamics of Cropland and Cropping Pattern Change Analysis Using Landsat TM and IRS P6 LISS III Satellite Images with GIS

引用

Geo-Spatial Information Science 2009年第2期12卷 123-134页

作者： Md.Rejaur Rahman S.K.Saha dept. of geography and Environmental Studies University of Rajshahi

The study of the spatial patterns and temporal changes of cropland is important to understand the underlying factors and the functional effects of the agricultural landscape. On the other hand, crop dynamics mapping is essential to know the overall agro-spatial diversity of the area. Therefore, this paper addressed a spatio-temporal analysis of cropland and cropping pattern change in the Bogra district of Bangladesh over the last 16 years （between 1988/89 and 2004/05）. In this paper, crop mapping from multi-temporal and multi-sensor satellite images was described. Landsat TM and IRS P6 LlSS Ⅲ satellite images were used with GIS for spatial dynamics of cropland and cropping pattern change analysis. First, seasonal cropland maps were derived from object-based classification of satellite images, then two-date classified image differencing with GIS overlay technique and decision rules were applied. Cropping pattern change was analyzed in a spatial and quantitative way for the 16 years and for this, Integrated Land and Water Information System （ILWIS） and Land Change Modular （LCM） of IDRISl Andes were used. The results showed that in the area, mono crop cultivation was found in summer, but in winter, areas under different crop cultivation had changed dramatically. Change analysis showed that the changes mainly occurred in the north northwest and southwest of the areas, and during the time the highest change area was found under the rice-potato pattern.

关键词： cropland dynamics gain and loss of cropland spatial trend cropping pattern change Landsat TM and IRS P6 LISS Ⅲ GIS

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Role of debris flow on the change of^10Be concentration in rapidly eroding watersheds:a case study on the Seti River,central Nepal

引用

Journal of Mountain Science 2017年第4期14卷 716-730页

作者： KIM Dong Eun SEONG Yeong Bae CHOI Kwang Hee YU Byung Yong dept.of geography Korea UniversitySeoul 02841Korea Yeongsan River Basin Environmental Office Ministry of EnvironmentGwangju 61945Korea Korea Institute of Science and Technology Seoul 02792Korea

The concentration of cosmogenic loBe in riverine sediments has been widely used as a proxy for catchment-wide denudation rate （CWDR）. One of the key assumptions of this approach is that sediments originating from sub-basins with different erosional histories are well mixed. A tragic debris flow occurred in the Seti River watershed, central Nepal, on May 5, 2012. This catastrophic debris flow was triggered by slope failure on the peak of Annapurna IV and resulted in many casualties in the lower Seti Khola. However, it provided an opportunity to test the assumption of equal mixing of sediments in an understudied rapidly eroding watershed. This study documents the CWDR of ^10Be to evaluate the extent of the influence of episodic erosional processes such as debris flow on the spatio-temporal redistribution of loBe concentrations. Our data show that the debris flow caused little change in CWDR across the debris flow event. In addition to isotopic measurement, we calculated denudation rates by using the modeled concentrations in pre- and post-landslide sediments based on the local ^10Be production rate. The modeled result showed little change across the event, indicating that the debris flow in May 2012 played a minor role in sediment evacuation, despite the rapid erosion in the catchment. Our study concludes that although the 2012 event caused many casualties and severe damage, it was a low-magnitude, high frequency event.

关键词： Seti River Beryllium-10 (^10Be) Catchment-wide denudation rate (CWDR) Debrisflow Episodic erosional processes

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Mapping the multi-hazards risk index for coastal block of Sundarban,India using AHP and machine learning algorithms

引用

Tropical Cyclone Research and Review 2022年第4期11卷 225-243页

作者： Pintu Mandal Arabinda Maiti Sayantani Paul Subhasis Bhattacharya Suman Paul dept.of geography Sidho-Kanho-Birsha UniversityPuruliaW.B.India dept.of geography Vidyasagar UniversityMedinipurW.B.India dept.of Economics Calcutta UniversityKolkataW.B.India dept.of Economics Sidho-Kanho-Birsha UniversityPuruliaW.B.India

Global climate change,climate extremes,and overuse of natural resources are all major contributors to the risk brought on by *** I West Bengal state of India,the Pathar Pratima Block frequently experiences a variety of risks that result in significant loss of life and *** order to govern coastal society,it is crucial to measure and map the multi-hazards risk *** depict the multi-hazards vulnerability and risk status,no cutting-edge models are currently being *** distinct physical vulnerabilities is possible using a variety of cutting-edge machine learning *** study set out to precisely describe multi-hazard risk using powerful machine learning *** study involved the use of Analytic Hierarchical Analysis and two cutting-edge machine-learning algorithms-Random Forest and Artificial Neural Network,which are yet underutilized in this *** multi-hazards risk was determined by taking into account six *** southern and eastern regions of the research area are clearly identified by the multi-hazards risk maps as having high to extremely high hazards risk *** hazards and embankment breaching are the main dominant factors among the *** machine learning approach is the most accurate model for mapping the multi-hazards risk where the ROC result of Random forest and artificial neural network is more than the conventional method *** RF is the most validated model than the other *** effectiveness,root mean square error,true skill statistics,Friedman and Wilcoxon rank test,and area under the curve of receiver operating characteristic tests were used to evaluate the prediction capacity of newly constructed *** RMSE values of 0.24 and 0.26,TSS values of 0.82 and 0.73,and AUC values of 88.20%and 89.10%as produced by RF and ANN models,respectively,were all excellent.

关键词： Cyclone Livelihood Multi-hazards Risk Machine-learning

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Microstructure and phase formation of mullite-Pr6O11 composite prepared by spark plasma sintering

引用

Journal of Rare Earths 2023年第2期41卷 283-289页

作者： Ehsan Ghasali Davoud Ghahremani Yasin Orooji Aida Faeghi-nia Asghar Kazem-zadeh Touradj Ebadzadeh College of geography and Environmental Sciences Zhejiang Normal UniversityJinhua 321004China Ceramic dept. Materials and Energy Research CenterAlborzIran Department of Engineering Maybod BranchIslamic Azad UniversityMaybodIran

The present work investigates the effect of high praseodymium oxide(Pr6O11)content on the microstructure and phase formation of mullite(3Al_(2)O_(3)·2SiO_(2))precursor by means of the spark plasma sintering process.30 wt%Pr6O11was added to a mullite precursor consisting of aluminum nitrate nonahydrate and tetraethyl orthosilicate through a high energy mixer mill in ethanol *** spark plasma sintering was performed at a te mperature of 1200℃under 23 Pa vacuum co nditions by applying initial and final pressure of 10 and 30 MPa,*** analysis confirms the existence of mullite,alumina,Pr6O11,Pr2O3and quartz as the only crystalline *** images reveal an interesting deposition of hexagonal-shaped Al_(2)O_(3)particles on polished surfaces and complex oxide phases of the fiber network adhering to alumina particles in the form of tails seen on the fracture ***,the bending strength of 213±21 MPa,Vickers hardness of 9.3±0.1 MPa and fracture toughness of6.21±0.12 MPa·m1/2are obtained for the prepared composite.

关键词： Mullite Pr6O11 Composite Spark plasma sintering Rare earths

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Land Suitability Evaluation for Agricultural Cropland in Mongolia Using the Spatial MCDM Method and AHP Based GIS

引用

Journal of Geoscience and Environment Protection 2017年第9期5卷 238-263页

作者： Munkhdulam Otgonbayar Clement Atzberger Jonathan Chambers D. Amarsaikhan Sebastian Bock Jargaltulga Tsogtbayar Institute of geography-geoecology Mongolian Academy of SciencesUlaanbaatarMongolia Institute of Surveying Remote Sensing and Land InformationDepartment of Landscape Spatial and Infrastructure ScienceUniversity of Natural Resources and Life SciencesViennaAustria Eng-Geo Tech LLC UlaanbaatarMongolia

The purpose of this study was to prepare a cropland suitability map of Mongolia based on comprehensive landscape principles, including topography, soil properties, vegetation, climate and socio-economic factors. The primary goal was to create a more accurate map to estimate vegetation criteria (above ground biomass AGB), soil organic matter, soil texture, and the hydrothermal coefficient using Landsat 8 satellite imagery. The analysis used Landsat 8 imagery from the 2016 summer season with a resolution of 30 meters, time series MODIS vegetation products (MOD13, MOD15, MOD17) averaged over 16 days from June to August 2000-2016, an SRTM DEM with a resolution of 30 meters, and a field survey of measured biomass and soil data. In total, 6 main factors were classified and quality evaluation criteria were developed for 17 criteria, each with 5 levels. In this research the spatial MCDM (multi-criteria decision-making) method and AHP based GIS were applied. This was developed for each criteria layer’s value by multiplying parameters for each factor obtained from the pair comparison matrix by the weight addition, and by the suitable evaluation of several criteria factors affecting cropland. General accuracy was 88%, while PLS and RF regressions were 82.3% and 92.8%, respectively.

关键词： Land Suitability MCDM Boolean and Fuzzy Analysis AHP RF and PLS Regression

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：