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To deformation vector special solution in mining subsidence and ground and rock movements

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中国有色金属学会会刊：英文版 2005年第S1期15卷 294-298页

作者： V. Sedlák P. Blit'an Technical University of Koice Faculty of Mining Ecology Process Control & Geotechnologies Institute of Geodesy & GIS Park Komenského 19 SK-04384 Koice SlovakiaTechnical University of Koice Faculty of Mining Ecology Process Control & Geotechnologies Institute of Geodesy & GIS Park Komenského 19 SK-04384 Koice Slovakia

The paper presents some specific procedures in modelling a deformation vector at deformation investigation of various engineering structures, buildings or terrain surfaces which are exposed by abiotik factors, for example by underground mining activities or recent geotectonic movements. A specific problem in deformation measurements is solved, when the same conditions of a monitoring network structure cannot be kept during all periodic observations.

关键词： deformation vector mathematical modelling geodetic periodic monitoring

Parallel scheduling strategy of web-based spatial computing tasks in multi-core environment

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High Technology Letters 2014年第4期20卷 395-400页

作者：郭明强 Huang Ying Xie Zhong Faculty of Information & Engineering China University of Geosciences gis Software and Application Project Research Center of the Educational Department

In order to improve the concurrent access performance of the web-based spatial computing system in cluster,a parallel scheduling strategy based on the multi-core environment is proposed,which includes two levels of parallel processing *** is that it can evenly allocate tasks to each server node in the cluster and the other is that it can implement the load balancing inside a server *** on the strategy,a new web-based spatial computing model is designed in this paper,in which,a task response ratio calculation method,a request queue buffer mechanism and a thread scheduling strategy are focused *** results show that the new model can fully use the multi-core computing advantage of each server node in the concurrent access environment and improve the average hits per second,average I/O Hits,CPU utilization and *** speed-up ratio to analyze the traditional model and the new one,the result shows that the new model has the best *** performance of the multi-core server nodes in the cluster is optimized;the resource utilization and the parallel processing capabilities are *** more CPU cores you have,the higher parallel processing capabilities will be obtained.

关键词： parallel scheduling strategy the web-based spatial computing model multi-core environment load balancing

Using gis and Remote Sensing in Assessment of Water Scarcity in Nakuru County, Kenya

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Advances in Remote Sensing 2017年第1期6卷 88-102页

作者： Catherine Changwony Arthur W. Sichangi Moses Murimi Ngigi Institute of Geomatics GIS and Remote Sensing (IGGReS) Dedan Kimathi University of Technology Nyeri Kenya

Water is at the core of sustainable development and is critical for socio-economic development, healthy ecosystems and for human survival. This research study has been carried out in Nakuru County, a tropical region in the Rift Valley of Kenya, bounded between latitude 0.28°N and 1.16°S, and longitude 36.27°E and 36.55°E. The objective of the study has been to use gis and remote sensing in assessment of water scarcity using Land use Land cover area changes, standard precipitation index and crop yields. Landsat satellite images for the year 1985, 1995, 2005 and 2015 were used. Classification was done using maximum likelihood algorithm while classification accuracy assessment entailed the use of confusion matrix method and ground truth data. Post classification change detection results gave percentage cropland areas as 21% in 1985, 29% in 1995, 53% in 2005 and also 53% in 2015. Eleven (11) ground rainfall stations and TRMM satellite rainfall data from 1985 to 2015 has been used to show meteorological drought. Validation of rainfall data done using correlation coefficient (R2) and root mean square (RMS) methods showed that ground rainfall data and TRMM data correlate. Modelling of 3 months SPI for each of the three seasons (MAM, JJA and OND) has been done using interpolation distance weighted method (IDW). 3 months SPI time scales curves gave October 1987 May 1993, and July 2004 as water scarce and dry seasons and were categorized as either Normal, moderately dry, severely dry and extremely dry. Crop yield trends curves showed crop yield decrease in this identified water scarce and dry years. Conclusion reached is that crop yields is not dependent on size of land ploughed only but mostly on rainfall quantities. Therefore, the findings of this research can be used as drought monitoring tools.

关键词： Land Use Land Cover (LULC) Meteorological Drought Standard Precipitation Index (SPI) Water Scarcity

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基于gis的湘东北万古地区金矿床靶区预测

矿床地质 2002年第S1期21卷 1128-1131页

作者：邓吉秋鲍光淑刘斌中南大学gis研究中心湖南长沙410083

在融合万古地区多源地学资料的基础上,总结万古地区的金矿床成矿特征,利用层级权重叠加模型和BP网络算法,建立评价的指标模型,运用gis的空间分析功能,实现对研究区的预测,并圈定预测靶区。

关键词：金矿床成矿特征指标模型空间分析预测靶区

Preliminary Calibration of GPS Signals and Its Effects on Soil Moisture Estimation

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Acta meteorologica Sinica 2013年第2期27卷 221-232页

作者：万玮李黄陈秀万罗鹏万家欢 Institute of Remote Sensing and gis Peking University Meteorological Observation Center of China Meteorological Administration 92292 Troops PLA

In recent years, Global Navigation Satellite Systems Reflectometry （GNSS-R） is developed to estimate soil moisture content （SMC） as a new remote sensing tool. Signal error of Global Positioning System （GPS） bistatic radar is an important factor that affects the accuracy of SMC estimation. In this paper, two methods of GPS signal calibration involving both the direct and reflected signals are introduced, and a detailed explanation of the theoretical basis for such methods is given. An improved SMC estimation model utilizing calibrated GPS L-band signals is proposed, and the estimation accuracy is validated using the airborne GPS data from the Soil Moisture Experiment in 2002 （SMEX02）. We choose 21 sites with soybean and corn in the Walnut Creek region of the US for validation. The sites are divided into three categories according to their vegetation cover： bare soil, mid-vegetation cover （Mid-Veg）, and high-vegetation cover （High-Veg）. The accuracy of SMC estimation .is 11.17% for bare soil and 8.12% for Mid-Veg sites, much better than that of the traditional model. For High-Veg sites, the effect of signal attenuation due to vegetation cover is preliminarily taken into consideration and a linear model related to Normalized Difference Vegetation Indices （NDVI） is adopted to obtain a factor for rectifying the ＂over-calibration＂, and the error for High-Veg sites is finally reduced to 3.81%.

关键词： GNSS-R soil moisture signal calibration bistatic radar

Temporal trends of hydro-climatic variables and their relevance in water resource management

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International Journal of Sediment Research 2021年第1期36卷 63-75页

作者： Karim Solaimani Mahmoud Habaibnejad Abdollah Pirnia gis Centre University of Agricultural and Natural Resources of Sari Department of Watershed Management University of Agricultural and Natural Resources of Sari

Identification of temporal changes in hydrological regimes of river basins is an important topic in contemporary hydrology because of the potential impacts of climate change on river flow *** this purpose,long-term historical records of rainfall(P),runoff(Q) and other climatic factors were used to investigate hydrological variability and trends in the Tajan River Basin over the period *** evaporation(E),rainfall variability index(d),evaporation ratio(CE) and runoff ratio(CQ) were estimated from the available hydroclimatological ***-Kendall trend analysis and nonparametric Sen’s slope estimates were performed on the respective time series variables to detect monotonic trend direction and magnitude of change over *** variability index showed that1973 was the wettest year(δ=+2.039) while 1985 was the driest(δ=-1.584).Also,decades 69-78 and89-98 were recognized as the wettest and driest decades *** gradient of variation of climatological parameters showed that during the study period,all three parameters of rainfall,evaporation and runoff have decreased and the variations of rainfall and evaporation were significant at the95% *** of hydrological changes due of dam construction(1999) showed that the amount and annual distribution of discharge were completely different pre and post-dam *** decreased in high water months and increased in low water months to meet water supply demands,especially for *** relationship between temperature and rainfall trends is compared for three stations in Mazandaran Province(Gorgan,Babolsar and Ramsar) from 1956 to 2003 and nine other stations with different statistical periods of 19-36 years,relating trends to northern hemisphere and global *** in temperature were accompanied by decreases in rainfall,and vice *** trends were not observed in northern hemisphere and world scales,where temperature increases are accompanied b

关键词： Climate change Human activity Hydroclimatological Trend analysis Mazandaran Tajan basin

基于实体对象树FOOT模型和四层体系结构的gis方法研究

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中国图象图形学报（A辑） 2004年第9期9卷 1135-1144,F006页

作者：刘仁义刘南谢炯冯杭建李伟严志民何江俞剑君夏凯阮淼钎浙江大学gis重点实验室杭州310028

提出了面向地理空间实体对象树模型 (FOOT) ,首先重点讨论了空间分区、空间聚簇、空间索引 ,然后分析了四层结构设计中的数据库服务层、应用接口层、应用层相关技术。基于所提出的空间数据组织方法和系统结构 ,介绍了具有海量空间数据... 详细信息

提出了面向地理空间实体对象树模型 (FOOT) ,首先重点讨论了空间分区、空间聚簇、空间索引 ,然后分析了四层结构设计中的数据库服务层、应用接口层、应用层相关技术。基于所提出的空间数据组织方法和系统结构 ,介绍了具有海量空间数据管理的系统功能模块 ,并提供了详细的对象逻辑关系说明。同时在对 FOOT模型和系统实现的关键技术进行设计的基础上 ,给出了一个基于 L inux操作系统和 Oracle数据库的分布式海量空间数据处理平台实例。采用 30 GB的空间数据测试结果表明 ,系统实现了面向实体的空间数据组织、统一的海量空间数据管理以及分布式空间数据计算等主要目标。该系统用于对全国 1∶ 4 0 0万土地利用图、1∶ 4 0 0万市县行政图数据上载的试验表明 ,不仅显示速度较快 ,且图形裁剪、空间叠加、缓冲分析等效率较高 ,验证了 FOOT模型的正确性、有效性、合理性。

关键词：实体对象分布式四层结构聚簇 Linux操作系统体系结构树模型海量空间数据地理空间实体空间索引

Landfill Siting Evaluation Using gis and Multi-Criteria Decision-Making Method: A Case Study: Dammam Municipal Solid Waste Landfill

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Journal of Geographic Information System 2021年第4期13卷 508-522页

作者： Nora Al Khaldi Firdos Almadani Sara Ouerghi Department of Geography and gis Faculty of Arts & Humanities King Abdulaziz University Jeddah Saudi Arabia

Waste landfills are a prominent global issue that does not concern a country without the other because of its long-term effects especially in the environmental aspect. As these pose an environmental threat to water, air and soil;and directly affect human life and health. Accordingly, this research uses the integration of Geographic Information Systems (gis) and Multi-Criteria Decision-Making (MCDM) approaches to assess the location of the municipal solid waste dump in Dammam, which was established in (2000AD) twenty years ago, due to the lack of recent studies assessing the current status of the landfill and whether it is in a suitable location and keeps pace with the population and urbanization increase in the region. For this purpose, the researchers are using the tools and techniques of gis to evaluate eight criteria on the study area. The required standards were directed to the landfill site and transformed into maps that represent the most important economic, social, environmental, geological, geomorphological and Public Acceptance standards. These standards have been processed using the tools of spatial and statistical analyses. Analytic Hierarchy Process (AHP) is implemented in geographical information system for building the suitable cartographic model, and thus allowed to determine the suitable degree of Dammam municipal solid waste landfill site in light of the study criteria. The study concluded that the current landfill site achieves a good degree of suitability, as it achieved 63% measured against the quality standards set by the study, and that the current landfill site conforms to most of the criteria in this study to a good degree. But it violates two standards, which are distance from wells standard and distance between landfill and the center of waste generation standard.

关键词： Landfill Site Criteria Weights gis Analytic Hierarchy Process (AHP)

Harmonization of Political and Administrative Boundaries in Kenya Using gis: A Case Study of Mavoko Constituency

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Journal of Geographic Information System 2017年第2期9卷 141-157页

作者： Kyatu Irene Godfrey Makokha Moses Ngigi Institute of Geomatics GIS and Remote Sensing (IGGReS) Dedan Kimathi University of Technology Nyeri Kenya

The objective of this research was to harmonize political and administrative boundaries in Mavoko Constituency, Machakos County, Kenya, using geo-spatial technology and public consultation in order to address the numerous disputes that exist. Specifically, the project focused on analyzing the existing electoral and administrative boundaries in the area of study by identifying all existing gaps and overlaps, rectifying the identified gaps and overlaps and created a web based geo-portal of the harmonized sub location boundaries to enable sharing. This was achieved through first putting the various datasets on the same Spatial Reference System and comparing them in order to identify and rectify them using various geospatial operations, public consultation and field work. The result was a single harmonized layer for the sub location data set for the study area. The project finally developed a customized gis web based portal for sharing the harmonized Sub location boundary. This was uploaded on an open source platform, which has the capability for offline use in the field. The project worked on a hypothesis that if the sub location boundaries adopted by the various Government and Public organizations and individuals doing any kind of mapping in Kenya was a single harmonized data set, the emerging issues on boundary disputes between Counties, Constituencies and County Assembly Wards (CAW’s) would not occur. This is because there would be authentic, consisted and authoritative geo-information which maintains a harmonized, consistent, reusable and readily available data. The development of the geo portal ensured that the results of the research are easily accessible on ***/mavoko.

关键词： Boundaries Data Sharing Geo Portal gis Harmonization