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991.
利用重庆地区1999年和2018年气象数据, 分别采用薄盘光滑样条、协同克里金、普通克里金、反距离加权4种方法, 从年和月两种尺度对气温、降水、太阳总辐射三个要素进行空间插值; 采取交叉验证方法, 用MAE、MRE、RMSE评估插值精度, 确定各要素最优插值方法。结果表明: 气温和太阳总辐射最优插值方法为薄盘光滑样条, 降水为反距离加权; 插值精度上气温、太阳总辐射高值月份优于低值月份, 降水则相反, 但三个要素均表现出年尺度优于月尺度。MRE检验表明, 插值精度为气温>太阳总辐射>降水, 1999年年尺度插值精度分别为1.86%、4.60%、6.87%, 月尺度插值精度分别为2.79%、5.82%、17.42%;2018年太阳总辐射年、月尺度插值精度分别为3.03%、4.88%, 区域站加密后气温、降水年尺度插值精度分别为2.03%、11.20%, 月尺度对应插值精度分别为3.20%、23.14%。 相似文献
992.
To block human–mosquito interactions by eliminating dengue vectors, Aedes aegypti L. and Aedes albopictus Skuse have been considered the main strategies for dengue prevention. Spatial targeting of dengue risk areas is the highest priority for implementing control measures. However, the frequency of human-Aedes mosquito contacts as human factors for assessing the risk of dengue has not been taken into account by past studies. The objective of this study is to clarify the geographic effects of crowd-gathering places on the frequency of dengue vector for assessing the spatial risk of exposure to dengue in Kaohsiung City, Taiwan. A geographic information system (GIS) was used to integrate crowd-gathering places and ovitrap locations for investigating potential human–mosquito contacts. A negative binominal regression was used to estimate the spatial risk of dengue by integrating vector mosquitoes from the ovitrap survey, urban environmental risk factors and human crowd-gathering places as the surrogate of human activities. We also compared the estimated spatial risk of exposure to dengue with traditional approaches. Our results indicated that the spatial distribution of the residential populations is not consistent with the locations of social activities. Additionally, people closer to crowd-gathering places have a higher frequency of contact with Ae. aegypti than with Ae. albopictus larvae. The dengue risk is caused by the human-Aedes aegypti contacts concentrated around city centers, while the risk caused by the human-Aedes albopictus contacts is distributed around the city boundary. Our study concluded that only relying on infected human cases or the abundance of vector mosquitoes is not enough for assessing the spatial risk of dengue. This reliance could ignore the areas with frequent vector existence and; therefore, result in the underestimated risk of dengue transmission. This study demonstrates the methodological framework for estimating the potential dengue risk and identifies the crowd-gathering places that facilitate dengue transmission. 相似文献
993.
Two common practices in modeling of crime when crime data is available for multiple years are using single-year crime data corresponding to census data and taking the average of crime rate (or count) over multiple years. Current theoretical and empirical literature provides little, if any, rationale in support of either practice. Averaging multiple years is purported to reduce heterogeneity and minimize the measurement error in the year-to-year emergence of crime. However, it is unclear how useful the analysis of averaged and smoothed data is for revealing the relationship between crimes and socio-demographic and economic characteristics of every single year. In order to more clearly understand these two approaches, this paper applies a seemingly unrelated regression model to assess the temporal stability of model parameters. The model accounts for spatial autocorrelation among crime rates and social disorganization variables at the block group level. 相似文献
994.
It is widely accepted that environmental change can influence human migration. In particular, the environment plays a role in migration processes in drylands, in which environmental change—including increasing variability of rainfall, increasing frequency of droughts, chronic water shortage, and land degradation—can heavily influence migration. However, systematic large-scale studies of the relationship between environmental factors and human migration are rare, and a global, consistent picture of environmental drivers of migration is lacking. In this study, we sought to fill this gap by analysing spatial patterns of environmental drivers of migration in drylands by performing a cluster analysis on spatially explicit global data. In this analysis, we focused explicitly on precipitation, aridity, drought, land degradation, soil constraints, and availability of cropland and pastures as potential environmental drivers of migration in drylands. In addition, we linked the identified clusters to two observed hotspots of out-migration—Burkina Faso and Northeast Brazil—to gauge the cluster results. Our results show that environmental drivers can be grouped into eight distinct clusters, and we identified the most severe environmental constraints for each cluster. These results suggest that out-migration—both in absolute and relative terms—occurs most frequently in a cluster that is constrained primarily by land degradation rather than water availability. 相似文献
995.
The high cost of land for housing within urban centres and the common desire to live within extensive residential areas in the green countryside have, in some cases, led to increasing residential development in the urban hinterland, often resulting in dispersed and sprawling development. In order to counteract such development this article seeks to provide a methodology for implementing strategies which aim is to achieve sustainable development in spatial planning. The proposed methodology, which is known as “backcasting”, aims to improve our ability to avoid undesirable future developments and to encourage those developments that are desirable. Backcasting has previously mostly been used within theoretical processes or frameworks. The backcasting exercise presented in this paper used a Python-based model to create often visionary future scenarios based on interviews with relevant experts, and then used these scenarios as input for a backwards running model. This model simulates a development that runs backwards in time, converging towards the present situation. The backcasting model presented herein has been applied to a case study in Salzburg, Austria. 相似文献
996.
Highly technological in vitro fertilization (IVF) treatment is available at relatively few medical centers in rural United States. This research derives a spatial accessibility surface for IVF centers in a rural Midwestern state through the application of computational methods that consider spatial and non-spatial parameters to discover potentially underserved areas in the state. These methods include a modified gravity model and techniques from spatial interaction modeling. The approach develops an enhanced accessibility index that incorporates three key sociodemographic variables describing patients seeking infertility healthcare in Iowa that have been identified based on a survey of IVF care practitioners in the state. Self-organizing map techniques are used to reveal cluster locations based on the degree of match between census sociodemographic data and the expert-identified variables. The spatial accessibility surface is combined with the sociodemographic clusters to define an enhanced measure of spatial accessibility. The results suggest that while the state's IVF centers are located in tracts characterized by high spatial accessibility, at least 19% of patients travel from census tracts classed as moderate to low accessibility. This result reveals some opportunities for service improvements for these locations. Interestingly, for tracts that are characterized as having a lower patient sociodemographic match, high spatial accessibility does not appear to be a factor that improves the likelihood of patient care, at least for the variables investigated as part of this research. 相似文献
997.
运用变异系数CV、泰尔系数T等指标,基于三大经济板块、17个市域、121个县域等不同空间程度,对1990年以来山东省区域经济发展水平的差异程度进行了分析。结果发现,空间尺度愈小,差异程度愈大,即县域间差异程度大于市域,市域大于板块,但从变化趋势看,板块间差异程度对全省经济发展水平差异的贡献度在提高。从三大板块内部看,鲁中地区经济发展水平差异程度大,鲁东和鲁南地区内部差异程度小。 相似文献
998.
利用1998～2008年江苏省能源消费数据,初步分析了江苏省能源碳排放的现状。以碳排放量、人均碳排放量和碳排放强度为指标,采用K-均值聚类分析方法对2002年、2008年江苏省县域的＂排放—效率＂类型进行了基本划分,并分析了各聚类碳排放格局特征。结果显示：GDP标准下的发达地区大多属于＂高排放＂类型,其中部分县市甚至属于＂高排放—低效率＂类型;以南京市区和徐州市区为代表的＂高排放—低效率＂地区,占全省碳排放量的一半,是江苏省节能减排的重点区域;不同聚类类型间呈现明显的空间自相关性,相同类型在空间上集中分布;局部格局的不稳定性,使县域在不同聚类类型间的跃迁行为时有发生。 相似文献
999.
为了解黄河三角洲湿地土壤线虫空间分布状况,以位于黄河三角洲湿地的孤东油田及黄河三角洲国家级自然保护区为研究地点,比较了油区与对照土壤线虫群落的空间分布特征。结果显示油区中食真菌和食植物线虫空间分布稍许聚集,但有随机因素。对照中食真菌线虫呈随机分布,食植物线虫呈聚集分布。油区中食细菌线虫趋于随机分布,对照样地则稍许聚集。另外,油区与对照土壤线虫及捕食性或杂食性线虫均呈空间聚集分布。通过油区与对照线虫群落营养类群空间分布特征的差异对比,可为黄河三角洲湿地生态系统健康状况评价提供有益的数据。 相似文献
1000.
江苏盐城市海滨土地利用对景观生态风险的影响 总被引：1，自引：0，他引：1
为了给江苏盐城海滨区域的生态环境管理提供理论和技术支持,利用地统计学理论模型和GIS技术,对江苏盐城海滨区域3个时期的土地利用和景观数据进行了生态风险评价和空间变异分析。研究结果显示:1987～2007年,盐城海滨区域和自然保护区内的土地利用结构均发生了显著变化,耕地逐渐增加,自然湿地迅速减少、人工湿地逐渐增加,人类对湿地景观的干扰程度逐渐加剧。自1987年以来,盐城市海滨区域的生态环境受人类活动的干扰增强,景观破碎化程度加剧,景观结构的变化已导致景观生态风险指数发生了显著的时空差异,景观生态风险呈增大的趋势。20 a间,盐城市景观生态风险的空间变异程度逐渐增大。1997年随机地域的空间异质性最大,景观生态风险的空间相关程度最大。盐城市海滨区域的景观生态风险的空间异质性(自相关)尺度和方向性也发生显著变化。各时段该区域东西方向上的变异大于南北方向上的变异;在东西方向上,景观生态风险强度呈现由低变高,而后又降低的特点,最高风险强度带位于西部农田与东部光滩沼泽交界的过渡地带。 相似文献