共查询到20条相似文献，搜索用时 15 毫秒
1.
设计了应用于静力触探中的数据采集系统,给出了系统电路原理图并主要介绍了MAX132芯片及它的软件算法。该系统以AT89C2051单片机为控制核心,主要采用可编程的±18位串行A/D转换器MAX132进行数据采集并转换,通过RS232串行通信接口与上位机进行异步串行通信。 相似文献
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吉林省重大暴雨过程灾害损失风险预评估 总被引：4，自引：1，他引：3
利用吉林省50县市1951-2013年逐日降水资料、暴雨灾情损失数据,1：5万DEM数据、水系、TM遥感卫星影像资料以及GDP、人口等数据,探讨了吉林省重大暴雨过程灾害损失风险的主要影响因素,确立了各因素的权重系数,构建了吉林省重大暴雨过程灾害损失风险评估模型.利用过程预报降雨量对2013年8月14-17日的重大暴雨过程灾害损失风险进行了预评估.结果表明：重大暴雨过程灾害损失综合风险的高值区分布在四平、辽源大部以及长春、吉林、通化城区附近,风险偏高区位于中南部,西部地区和东北部地区为中低风险区.灾害损失风险评估模型预评估效果良好,可在实际的暴雨过程灾害损失风险预评估业务中使用,由于通过该模型的评估结果可迅速圈定各级洪涝风险区,对提高重大暴雨过程应对能力、减少灾害损失以及防灾减灾意义重大. 相似文献
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平行裂隙沿程水头损失规律的实验研究 总被引：1，自引：1，他引：0
为了研究管道-裂隙介质水动力过程,利用不同隙宽及横向宽度的平行裂隙进行室内模拟试验,探究单一平行裂隙中水流流动产生的沿程水头损失随裂隙宽度及横向宽度的变化规律。结果表明:当隙宽小于1.84 mm时,沿程水头损失与流速呈一次函数关系,并且沿程水头损失随裂隙宽度的增大而减小。通过对比管道层流沿程水头损失公式与立方定律,发现管道和裂隙在计算沿程水头损失时主要差别在于后者忽略横向宽度的影响,指出裂隙长宽比在确定管道与裂隙界限中起重要作用。同时通过分析试验所取得的数据,得出裂隙沿程水头损失随裂隙长宽比的增大呈现先减小后增大的趋势,并建立沿程水头损失随裂隙长宽比变化的经验公式。 相似文献
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降雨型滑坡在强降雨条件下常突然发生,启动后运动速度大,破坏力强,对其运动与堆积过程的预测是滑坡危险性分析中的难题。以湖南省宁乡县2017年7月1日突发的王家湾滑坡为例,在现场调查的基础上,系统研究了滑坡诱发因素和高速运动机理,发现强降雨和孔隙水压力上升是王家湾滑坡的主要诱发因素,高速滑动主要由于滑坡处斜坡坡度陡、滑带抗剪强度快速损失所致。利用Surfer和ArcGIS软件处理基础数据,建立了滑坡三维模型,并基于有限体积法采用DAN3D软件模拟分析了王家湾滑坡整个运动过程,研究了滑坡启动后运动速度、滑移范围和堆积厚度,模拟结果与现场调查数据基本一致。 相似文献
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由大规模抽取地下水和工程建设引发的地面沉降广泛分布于世界各大平原,地面沉降地质灾害使城市损失标高,增加城市在洪涝灾害中的生命财产损失。基于60景Sentinel-1影像,采用PS-InSAR(永久散射体合成孔径雷达干涉测量)技术获取了宁波市2017～2021年平原区地表形变,利用同期水准数据进行了精度和可靠性评定,监测和分析结果表明工程建设是现阶段引发宁波市地面沉降的主要因素;杭州湾新区为代表的沿海围垦区地面沉降与围垦和工程建设时间密切相关;城市建成区地面沉降局限于近期的工程建设区域内,且沉降衰减相对较快。 相似文献
8.
地质灾害经济损失评价方法研究 总被引：9，自引：1，他引：8
本文对受灾体价值损失核算方法,历史灾害破坏损失评价方法,地质灾害期望损失评价方法进行了系统研究,提出了成本价值或修复成本价值损失核算模型,收益损失核算模型,成本－收益价值损失核算模型;构成了历史灾害破坏损失评价模型;研究了点评估、面评估期望损失评价方法、步骤及分析模型。 相似文献
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Whilst the UK is planned to have a census in 2021, it may well be the last and there is official acknowledgement that the country’s statistical system should be enhanced by greater use of administrative data. Thus, there is a pressing need to understand whether alternative data sources are fit for social science purposes. This study assesses the potential of utilizing administrative statistics for investigating the relationships between health and socioeconomic distributions for small areas; a type of study regularly carried out using census data. Pairs of administrative measures of health and deprivation indicator variables are compared with census equivalents for lower super output area geographies in England in 2001. The administrative datasets are then used to derive health measures and deprivation indexes for the time points 2001, 2006 and 2010. Inequalities in health are then analysed using administrative data derived area measures with health found to be poorer in areas with socioeconomic disadvantage. Overall, the administrative datasets used here reveal very similar patterns of health and deprivation to the decennial census suggesting they are viable alternatives and have great potential to enhance the country’s statistical system given their availability outside census years. 相似文献
12.
Assessing the use of global land cover data for guiding large area population distribution modelling
Gridded population distribution data are finding increasing use in a wide range of fields, including resource allocation,
disease burden estimation and climate change impact assessment. Land cover information can be used in combination with detailed
settlement extents to redistribute aggregated census counts to improve the accuracy of national-scale gridded population data.
In East Africa, such analyses have been done using regional land cover data, thus restricting application of the approach
to this region. If gridded population data are to be improved across Africa, an alternative, consistent and comparable source
of land cover data is required. Here these analyses were repeated for Kenya using four continent-wide land cover datasets
combined with detailed settlement extents and accuracies were assessed against detailed census data. The aim was to identify
the large area land cover dataset that, combined with detailed settlement extents, produce the most accurate population distribution
data. The effectiveness of the population distribution modelling procedures in the absence of high resolution census data
was evaluated, as was the extrapolation ability of population densities between different regions. Results showed that the
use of the GlobCover dataset refined with detailed settlement extents provided significantly more accurate gridded population
data compared to the use of refined AVHRR-derived, MODIS-derived and GLC2000 land cover datasets. This study supports the
hypothesis that land cover information is important for improving population distribution model accuracies, particularly in
countries where only coarse resolution census data are available. Obtaining high resolution census data must however remain
the priority. With its higher spatial resolution and its more recent data acquisition, the GlobCover dataset was found as
the most valuable resource to use in combination with detailed settlement extents for the production of gridded population
datasets across large areas. 相似文献
13.
Social segregation and academic achievement in state-run elementary schools in the municipality of Campinas, Brazil 总被引：1，自引：0，他引：1
Space not only reflects social inequality, it also reinforces the advantages or disadvantages associated with social class. However, the study of how neighbourhoods affect their residents has only recently entered the debate on urban poverty in Latin America. We use 2000 data from the Brazilian population census, school census, and the state of São Paulo’s educational evaluation system to analyze the relationship between school infrastructure, school academic achievement, and the neighbourhoods in which these schools are located. Our analyses indicate that state-run elementary schools located in areas of concentrated poverty have lower academic achievement in mathematics tests and Portuguese than mixed and affluent areas of the city, even though these schools are all administered by the same government body. We end with a discussion of the relationship between Brazilian education policy and its influence on spatial differences in São Paulo State. 相似文献
14.
J. F. Olorunfemi Dr. 《GeoJournal》1982,6(3):225-230
For effective planning purposes, reliable and up-to-date statistics on population is very important in any country. However, in Nigeria, population census is such an infrequent exercise that data on city population is not readily available. The inherent data delivery lag time period, between the physical collection and actual publication of the results of censuses contributes to the obsolescency of census data.This situation calls for the development of appropriate techniques of collecting up-to-date population data in Nigeria.The use of aerial photography for collecting certain types of census information has been suggested as a procedure that can successfully supplement existing techniques. Three models viz: (1) the Land Use Model (2) the House Counting Method and (3) the Land Area Method were developed and applied in the estimation of the 1973 population of Ilorin. It is being suggested here that these methods can be employed in making the much needed intercensal population estimation for planning purposes readily available. In addition, this approach is not as sensitive as census per se in Nigeria. 相似文献
15.
Maps of factors contributing to groundwater contamination risk have been produced for a sector of the province of Milan to support decision-making in land planning and management.
Risk assessment has considered factors related to: natural vulnerability, hazard due to human activities and costs resulting from pollution. In order to evaluate existing hazard, a specific census was carried out over the area and industrial, agricultural and quarrying activities were mapped. Industrial activities were first divided into 4 groups according to national waste type regulation.
The number of data and the density of mapped factors necessitated the use of a land information system for data storage and management and map design. 相似文献
Risk assessment has considered factors related to: natural vulnerability, hazard due to human activities and costs resulting from pollution. In order to evaluate existing hazard, a specific census was carried out over the area and industrial, agricultural and quarrying activities were mapped. Industrial activities were first divided into 4 groups according to national waste type regulation.
The number of data and the density of mapped factors necessitated the use of a land information system for data storage and management and map design. 相似文献
16.
作为基桩完整性检测的常规方法,低应反射波法因为野外数据采集快,成本低,效率高,便于大面积普查等优点,而在基桩完整性检测中得到广泛应用。但在实际检测中往往由于不严格按骤步进行检测或采用方法不当等原因,而使实测波形不能真正反映基桩的实际情况,因而造成错判、误判等,严重影响了工程质量和施工单位的正常工作。介绍了反射波法检测基桩完整性的几个步骤,并着重提出了现场检测中的一些注意事项。 相似文献
17.
Lise Tole 《GeoJournal》2002,57(4):251-271
This study uses MSS data to derive sub-national level deforestation rates at the constituency administrative level for Jamaica
for 1987 and 1992. It then investigates the role of poverty and population in driving forest loss during this period by linking
these estimates in a GIS with constituency level demographic and socioeconomic census data for the island. OLS regression
results support the importance of population pressures and poverty in driving the destruction of Jamaica's forests and the
relative contribution to deforestation of their various measures are noted and discussed. In addition to providing information
on Jamaica's deforestation attributes, the study demonstrates how remotely sensed data can be used in conjunction with household
census data to derive information on human-forest interactions at the sub-national level. A small simulation experiment based
on regression results using key variables suggests that under any scenario, the impacts of key social and demographic changes
on Jamaica's remaining forest cover may be substantial by the year 2010.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
18.
Urban social vulnerability assessment with physical proxies and spatial metrics derived from air- and spaceborne imagery and GIS data 总被引：2，自引：0，他引：2
Risk management in urban planning is of increasing importance to mitigate the growing amount of damage and the increasing
number of casualties caused by natural disasters. Risk assessment to support management requires knowledge about present and
future hazards, elements at risk and different types of vulnerability. This article deals with the assessment of social vulnerability
(SV). In the past this has frequently been neglected due to lack of data and assessment difficulties. Existing approaches
for SV assessment, primarily based on community-based methods or on census data, have limited efficiency and transferability.
In this article a new method based on contextual analysis of image and GIS data is presented. An approach based on proxy variables
that were derived from high-resolution optical and laser scanning data was applied, in combination with elevation information
and existing hazard data. Object-oriented image analysis was applied for the definition and estimation of those variables,
focusing on SV indicators with physical characteristics. A reference Social Vulnerability Index (SVI) was created from census
data available for the study area on a neighbourhood level and tested for parts of Tegucigalpa, Honduras. For the evaluation
of the proxy-variables, a stepwise regression model to select the best explanatory variables for changes in the SVI was applied.
Eight out of 47 variables explained almost 60% of the variance, whereby the slope position and the proportion of built-up
area in a neighbourhood were found to be the most valuable proxies. This work shows that contextual segmentation-based analysis
of geospatial data can substantially aid in SV assessment and, when combined with field-based information, leads to optimization
in terms of assessment frequency and cost. 相似文献
19.
Goovaerts P 《Mathematical Geosciences》2010,42(5):535-554
A common issue in spatial interpolation is the combination of data measured over different spatial supports. For example,
information available for mapping disease risk typically includes point data (e.g. patients’ and controls’ residence) and
aggregated data (e.g. socio-demographic and economic attributes recorded at the census track level). Similarly, soil measurements
at discrete locations in the field are often supplemented with choropleth maps (e.g. soil or geological maps) that model the
spatial distribution of soil attributes as the juxtaposition of polygons (areas) with constant values. This paper presents
a general formulation of kriging that allows the combination of both point and areal data through the use of area-to-area,
area-to-point, and point-to-point covariances in the kriging system. The procedure is illustrated using two data sets: (1)
geological map and heavy metal concentrations recorded in the topsoil of the Swiss Jura, and (2) incidence rates of late-stage
breast cancer diagnosis per census tract and location of patient residences for three counties in Michigan. In the second
case, the kriging system includes an error variance term derived according to the binomial distribution to account for varying
degree of reliability of incidence rates depending on the total number of cases recorded in those tracts. Except under the
binomial kriging framework, area-and-point (AAP) kriging ensures the coherence of the prediction so that the average of interpolated
values within each mapping unit is equal to the original areal datum. The relationships between binomial kriging, Poisson
kriging, and indicator kriging are discussed under different scenarios for the population size and spatial support. Sensitivity
analysis demonstrates the smaller smoothing and greater prediction accuracy of the new procedure over ordinary and traditional
residual kriging based on the assumption that the local mean is constant within each mapping unit. 相似文献
20.
基于LUCC和夜间灯光辐射数据的张掖市甘州区人口空间分布建模 总被引：2，自引：1，他引：1
尽管近年来统计数据的生成技术有了很大提高, 但可用的详细人口数据始终难以得到满足.在一些自然-人文要素耦合的建模研究中, 如生态经济集成建模、 环境和健康分析等都需要基于区域尺度的栅格人口分布建模方法.随着GIS和RS技术的发展, 上述建模方法已有较大进步.利用GIS技术, 基于夜间灯光辐射数据和LUCC在象元栅格水平上构建张掖市甘州区人口空间分布. 首先对DMSP夜间灯光辐射数据进行重采样, 通过普通克里金插值获得灯光数据; 然后与LUCC叠加分析, 利用回归分析的方法获取研究区土地利用、 灯光辐射指标和人口统计数据之间的定量关系, 完成空间化.并在乡镇尺度上进行模型检验, 模型总体的调整R2为0.88, 标准误差为400, 为下一步开展时空变化分析提供支持. 相似文献