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1.
Governments are among the largest spenders in most countries, and their spatial allocation policies have considerable impact on variation in levels of well-being. In a preliminary attempt to develop a theory to account for the geography of government spending, this note uses electoral variables to estimate interstate variations in federal allocations to states within the U.S.A., based on a model of the politician as a vote-plurality maximizer. Results of the preliminary tests are encouraging and suggest lines for further investigation.  相似文献   

2.
《Geoforum》1986,17(1):69-79
Behaviour is influenced by available information, so that spatial variability in information availability should be associated with variability in associated behaviour. This hypothesis is tested against the pattern of voting at the 1983 general election in England, with the information variable indexed by the amount of spending by each party, at the constituency scale. The results show that for each party, the more that it spent (mainly on advertising) the more votes it got.  相似文献   

3.
Ji  Yuhe  Zhou  Guangsheng  Wang  Lixia  Wang  Shudong  Li  Zongshan 《Natural Hazards》2019,96(3):1213-1222

A long time series in crop yield is usually expressed as a long-term trend and a short-term fluctuation due to agricultural technological advance and climatic anomaly. The real climate risk is related to the short-term fluctuation in crop yield. In the paper, the climate risk of maize yield response to long-term climate variables is tested with the long time series (1961–2015) by a trend base line method. The long time series of maize yield is divided into short-term fluctuating meteorological yield and long-term trend yield. The long time series of climate variables are also divided into fluctuating variables and trend variables. After that, Pearson correlation analysis between fluctuating maize yield and fluctuating climate variables is used to identify risk factor causing maize yield fluctuation. Our results reveal that the main risk factors are night-time precipitation and extreme high temperature in growing season. Comparing climate risks in maize-producing provinces, much more climate risks are identified in some regions such as Liaoning province. The results provide useful information for reducing maize yield loss under climatic change.

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4.
Colin Flint 《GeoJournal》2000,51(3):145-156
This paper makes two contributions towards making a theoretically driven electoral geography a vital component of geography. First, a theoretical framework for the empirical analysis of elections is proposed that views elections as one component of the social construction of space while simultaneously illustrating how space structures electoral behavior. Second, the concepts of a geographic theory of voter mobilization need to be operationalized in such a way that space is an integral component of statistical analysis. The statistical concepts of spatial dependence and spatial heterogeneity are used to include electoral locales and the regionalization of voter mobilization in the analysis. The theoretical framework and statistical operationalization proposed are illustrated by a statistical analysis of the growth of the Nazi party vote in Baden between 1924 and 1932.  相似文献   

5.
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   

6.
How to integrate environmental geographic information and biodiversity data combined with management measures to effectively assess soil health is still an unresolved problem. This paper suggests an approach for systematically estimating soil quality and guiding ecological management. First, canonical correspondence analysis is used to predict the distributions of plant species or microorganism communities, principle pollutants and environmental variables from which spatial and environmental data are extracted by the geographic information system (GIS). Secondly, geostatistical methodologies are then used to estimate and quantify the spatial distribution characteristic of the species and pollutants and to create maps of spatial uncertainty and hazard assessment through ArcGis technology. Finally, redundancy analysis provides a suggestion about better management strategy and environmental factor for improving soil health and biodiversity. The combination of these methods with “3S” techniques as an assessment approach effectively meets the challenges for estimation and management in different soil environments.  相似文献   

7.
利用遥感、DEM、基础地理信息、土地利用变更调查、社会经济统计等各类数据和专题图件,以平江县为例,构建湖南典型贫困区土地生态状况综合评估体系,对平江县土地生态状况进行综合评估,并计算各个元指标障碍度。结果表明,平江土地生态质量总体较好,大部分地区表现为优良状态,土地生态质量空间差异性较大,在空间上呈现北低南高、西低东高的趋势。影响平江县和各个乡镇土地生态状况的主要障碍因子为湿地比例、林地年退化率、土地利用类型多样性指数、耕地比例、植被覆盖度,个别乡镇的主要障碍因子还包括水面比例和人口密度。通过对平江县土地生态状况进行综合评估与分析,寻找影响其土地生态健康发展的主要障碍因子,提出相关建议,以实现土地可持续利用,为湖南典型贫困区土地生态状况评估提供科学研究方法。  相似文献   

8.
遥感生态指数能对区域环境进行快速监测和评价,可实现对区域生态环境变化的可视化、时空分析及变化趋势预测。为评价兰州市生态红线保护区的生态保持和恢复情况,本文以兰州市2014—2017年的数据为研究对象,研究了兰州市在未划定生态红线保护区前的生态环境状况;又以兰州市生态红线保护区划定年2018年为起始,研究了兰州市2018—2021年的生态质量,计算结果显示,未划定生态红线保护区前,兰州市生态归一化指数均值为0.34,系统较稳定,环境整体质量较差;2018年以来,兰州市生态归一化指数均值为0.36,环境整体质量仍然处于较差的水平,但是生态系统的变化开始变得剧烈且往好的方向发展。通过构建灰度理论模型分析发现,兰州市未来几年内环境质量不断好转,预计2023年生态质量评级达到良好。  相似文献   

9.
Most of the existing predictive malaria risks spatial models use very broad spatial scales, and they are usually built-up for continental or national outlines. These models usually do not account for the complexity of socio-economic variables intervening into the malaria transmission process as well malaria prevention strategies. These spatial and thematic shortcomings are particularly interesting when looking at urban environments. This paper explains why a focus on urban malaria overcomes these shortcomings. A set of environmental variables derived from remotely sensed and ground climate station sources was used to build-up an ecological model. An original data collection process based on GPS measurements and retrospective interviews was introduced for the creation of various geoepidemiological and geosocial variables. Multinomial logistic models were used to predict and evaluate the contribution of various thematically separated groups of variables to malaria risk. Finally, it was possible to statistically and spatially evaluate the contribution of ecologic, socio-ecologic, socio-economic and behavioural characteristics of these groups of variables to malaria risks.  相似文献   

10.
According to a classical definition the size of a market area results from the spatial range of the demanded and/or supplied goods and services. Distance-sales-relations or price-sales-relations produce overlapping and interconnecting sales cones with fuzzy limits in space. Thus the problem consists in identifying boundaries or edges of boundaries which result from the intensity of (spatial) spending power flows or spatial consumer shopping behaviour defining a system of functional regions. They can be estimated empirically by surveys or by mathematical models. In the former case the customer flows or spending power flows themselves are empirically recorded, in the latter they are determined from structure data of the supply and demand locations taking the distance barrier into consideration. The methods and their variants are described, their strengths and weaknesses discussed and possible areas of application presented. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

11.
MAUP sensitivity analysis of ecological bias in health studies   总被引:1,自引:0,他引:1  
Ecological bias introduced by spatial data aggregation causes significant variation in correlation statistics between pathogen exposures and illness rates. Modifiable areal unit problem sensitivity analysis is introduced to investigate the impact of spatial aggregation on ecological bias. Simulation produces numerical estimates for the relative magnitudes of components that effect ecological bias: (1) spatial autocorrelation of exposure concentrations; (2) scaling; (3) zoning; (4) network-clustered structure of illness events; (5) clustering of exposure measurements; and (6) the statistical distribution of exposure concentrations. These six components are mixed and used to compare random illness patterns to patterns determined from a dose–response model. Of the six, spatial autocorrelation of exposure data has the greatest influence on ecological bias. Spatial aggregation can cause high correlations in random illness patterns. More importantly, if pathogen concentrations are randomly distributed in space, then there is a greater likelihood that data aggregation might obscure a strong association.  相似文献   

12.
13.
干旱区绿洲退耕还林工程绩效评价研究——以张掖市为例   总被引:1,自引:0,他引:1  
李玉文  徐中民 《冰川冻土》2009,31(3):546-552
退耕还林,重建生态环境,是当前实施西部大开发的根本切人点.退耕还林工程是通过把原本是林地或草地的耕地恢复成原来的土地利用类型,使受损或退化生态系统最终成为健康的生态系统,从而使当地生态环境更适合人类生存发展.从此目标出发,抛开经济利益而从自然生态系统恢复和社会心理影响等方面建立指标体系,利用主成分分析法综合评价了干旱区内张掖市的退耕还林绩效.结果表明:2002-2004年张掖市退耕还林工程执行效果较好,其中生态系统在数量上恢复较好的乡镇有明花乡;生态系统在质量上恢复较好的有明花乡和平川镇;工程执行过程中居民保护环境意识有较大提高的有民联乡和霍城镇;人们满意程度最高的是明花乡.总体上看,张掖市退耕还林工程执行绩效最好的是明花乡,其次是平川镇,最差的是永固镇,其余处于中间水平.最后,在分析张掖市退耕还林绩效差异基础上,针对提高退耕还林工程绩效提出一些建议.  相似文献   

14.
The ecological water conveyance project that pipes water from Daxihaizi reservoir to lower reaches of Tarim River has been implemented ten times since 2000. After ecological water conveyance, restoration has taken place for vegetation along the dried-up lower reaches of the Tarim River. The changes of vegetation fluctuated yearly due to ecological water conveyance. In order to reveal the detailed process of vegetation changes, remote sensing images from 1999 to 2010 were all classified individually into vegetated and non-vegetated areas using the soil-adjusted vegetation index threshold method. Then inter-annual changes of vegetation over a period of 12 years were obtained using a post-classification change detection technique. Finally, spatial–temporal changes distribution of vegetation cover and its response to ecological water conveyance were analyzed. The results indicate: (1) vegetation area increased by 8.52 % overall after ecological water conveyance. Vegetation between 2003 and 2004 increased dramatically with 45.87 % while vegetation between 2002 and 2003 decreased dramatically with 17.83 %. (2) Vegetation area gain is greater than vegetation loss during 1999–2000, 2001–2002, 2003–2004 and 2009–2010 periods. Although vegetation restoration is obvious from 1999 to 2010, vegetation loss also existed except for the periods above. It indicates that vegetation restoration fluctuated due to ecological water conveyance. (3) Spatial distribution of vegetation restoration presented “strip” distribution along the river and group shaper in the lower terrain area, while spatial distribution of vegetation loss mainly located in the upper reaches of river and area far away from the river. (4) Vegetation restoration area had a positive relative with total ecological water conveyance volume. The scheme and season of ecological water conveyance had also influenced the vegetation restoration. The vegetation change process monitoring, based on continuous remote sensing data, can provide the spatial–temporal distribution of vegetation cover in a large-scale area and scientific evidences for implementing ecological water conveyance in the lower Tarim River.  相似文献   

15.
基于景观生态学理论,借助多时相遥感数据与GIS空间分析技术,运用“压力-状态-响应(press-state-response,PSR)”模型,构建岩溶地区城市景观生态安全评价体系,通过空间叠加分析得到2000年和2013年贵阳市城市生态安全等级分布图,并就其空间分布规律与演化特征进行了对比分析,结果表明:2000年、2013年贵阳市城市生态安全指数均较低,2000年处于安全级别以上的值为3.04,2013年处于安全级别以上的值下降到1.78,在空间分布上呈西南向东北递增的趋势;在2000-2013年间,景观生态安全指数除湿地以外其他景观类型均呈现明显的下降趋势,其中农田恶化较为明显,湿地是唯一改善的景观类型。研究时段内贵阳市景观生态安全状况处于恶化趋势,因而建议在今后的城市规划与建设中应优化土地利用格局,以提高城市景观生态安全水平。   相似文献   

16.
典型地物波谱知识库建库与波谱服务的若干问题   总被引:15,自引:1,他引:14  
地物波谱知识库的建立旨在满足应用需求。为达到数据的共享,波谱知识库应对遥感实验测量的波谱数据和相关信息如观测规范、实验环境有清楚的说明,即要有完备的元数据让用户知道波谱知识库中是什么样的数据。为弥补地面测量数据与用户需要数据的时间空间尺度差异,用于外延观测数据的遥感物理模型必不可少;这要求收集分析遥感物理模型,评价其适用条件并创建模型元数据,使用户了解在其工作条件下有何适用的模型,模型的依据是什么;同时波谱库使用遥感物理解析模型和计算机模拟模型完成植被参数的时间扩展和沿叶片-冠层-像元 3个层次的观测尺度空间扩展,从而产生像元尺度可见光到热红外波段的参考波谱。为实现因特网上的波谱知识共享,需要研究如何组织波谱数据和模型,让用户方便地远程检索实测的典型地物波谱数据,并可以实时获取由遥感物理模型外延的波谱数据。从上述 3个方面归纳了波谱库建设和服务需要解决的 6个问题。  相似文献   

17.
Summary Algiers social ecology was formed by conflict between French colonialism and Algerian nationalism. In colonial time Algiers is dichotomized in an European urban core, interrupted only by some precolonial settlements (Kasbah of Algiers and Sidi M'Hamed) and the Algerian outer zones. The transformation of this ethnic-economic urban pattern into socio-economic urban zoning in post colonial time is shown by cross-sectional and longitudinal factor-ecological analysis. First analysis explores the changes in ecological structure by comparing two data-sets of census in colonial time (1954) and national independence (1966). Second approach explores the structure of ecological change interpreting the differences of variables in both points. Significant socio-ecological processes were Algerisation, diffusion of social groups, immigration and segregation of postrevolutionary elite. A model of decolonization spatial pattern is built up. The results are briefly discussed with other known ecological trend analysis.  相似文献   

18.
The purpose of this study is to analyze the development of the HIV epidemic in Finland in 1983–1994, and to predict the spatial distribution of new cases through 1997. The analysis is based on seroepidemiological data of all reported HIV carriers and a number of explaining variables based on individual level register data. Instead of focusing on populations of carriers and susceptibles, emphasis is placed on identifying the primary influences directing the epidemic as a spatial process. This is done by dividing Finland into 62 functional small area units and by assigning the risk of obtaining the virus to each unit based on behavioral, socioeconomic, interaction, and structural characteristics of the population. The approach is a multistep procedure including multivariate regression analysis, the potential model, and time series analysis. The model was used to produce a three-year forecast of the distribution of new HIV carriers in Finland. Compared with earlier studies of similar nature based on the use of administrative regional units, in this paper the forecast distribution of HIV cases is more closely related to the functional structure of the spatial system in Finland. Such an approach offers a method for producing more reliable short-term forecasts of the spatial distribution of new HIV cases. Three different spatial diffusion patterns were identified.  相似文献   

19.
黄河流域是我国目前主要的煤炭经济可采量和产能聚集地。了解和掌握黄河流域水资源及其变化不仅是推进黄河流域水资源节约集约利用的前提,更是开展黄河流域煤炭矿区生态保护与高质量发展的基础。相较于传统地面水资源监测手段受限于监测点分布和数目的影响,GRACE重力卫星为中长尺度陆地水储量时空变化研究提供一种新的途径。利用GRACE重力卫星数据,开展2002年4月到2017年6月黄河流域水储量的时空变化规律研究。利用纬圈长度加权平均,计算黄河上中下游水储量变化均值,发现黄河不同流段表现不同的变化趋势,且反映出2003年黄河流域水资源变化受到洪水等因素影响。进一步通过箱形图分析黄河流域上中下游水储量的月平均变化规律,反映出该流域“冬干春旱,夏秋多雨”的气候特点与水储量变化的密切关系。采用时间序列分解方法分析整个黄河流域水储量变化的趋势、年周期及半年周期等特征。结果表明,黄河流域水储量变化存在随经度由西向东递减趋势越来越明显的现象,其中黄河上游源头附近区域的水储量变化呈微弱的增长趋势;黄河流域水储量变化年周期和半年周期振幅存在明显区域差异,这与高山融雪、降水量的季节性差别及区域气候环境密切相关。了解和掌握上述黄河流域水储量时空变化,可为流域矿区的生态保护与可持续发展提供基础数据与参考。   相似文献   

20.
Yunjie Song  Xun Shi 《GeoJournal》2017,82(3):597-608
The exploration of the spatial association between Medicare physician spending and population densities and sizes could possibly facilitate the investigation of the causal mechanisms beneath the variation in medical care. We acquired the U.S. Medicare physician expenditures and regional demographic and geographic data in 2006 from the Dartmouth Atlas of Health Care. Six geographic units—states, counties, Hospital Referral Regions, Hospital Service Areas, Metropolitan Statistical Areas, and state non-Metropolitan Statistical Areas—were used as units of study. Pearson correlation analysis, multivariable regression, and partial correlation analysis were employed. Among six geographic units, Pearson correlation coefficients between Medicare physician expenditures and logarithmic population densities ranged from 0.42 to 0.63 (p < 0.05 for all), and between the expenditures and logarithmic population sizes from 0.31 to 0.65 (p < 0.05 for all). When population health, differential demand, market structure, and data reporting bias were controlled, population densities and sizes were positively associated with Medicare physician expenditures in most models. Population densities and sizes could explain considerable amounts of regional variation in Medicare physician spending. We concluded that Medicare physician spending was contingent on population densities and sizes. Because population densities and sizes are produced by more fundamental qualities such as natural environments and resources and thus are not easily manipulated, they are suggestive in health policy studies. Further research might investigate population distribution associated properties such as geographic distribution of health care resources, spatial dynamics of medical technology distribution, and cultural and psychological factors.  相似文献   

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