Building population mapping with aerial imagery and GIS data

Geospatial distribution of population at a scale of individual buildings is needed for analysis of people's interaction with their local socio-economic and physical environments. High resolution aerial images are capable of capturing urban complexities and considered as a potential source for mapping urban features at this fine scale. This paper studies population mapping for individual buildings by using aerial imagery and other geographic data. Building footprints and heights are first determined from aerial images, digital terrain and surface models. City zoning maps allow the classification of the buildings as residential and non-residential. The use of additional ancillary geographic data further filters residential utility buildings out of the residential area and identifies houses and apartments. In the final step, census block population, which is publicly available from the U.S. Census, is disaggregated and mapped to individual residential buildings. This paper proposes a modified building population mapping model that takes into account the effects of different types of residential buildings. Detailed steps are described that lead to the identification of residential buildings from imagery and other GIS data layers. Estimated building populations are evaluated per census block with reference to the known census records. This paper presents and evaluates the results of building population mapping in areas of West Lafayette, Lafayette, and Wea Township, all in the state of Indiana, USA.     

Environmental toxicology: population modeling of cod larvae shows high sensitivity to loss of zooplankton prey

Two factors determine whether pollution is likely to affect a population indirectly through loss of prey: firstly, the sensitivity of the prey to the pollutants, and secondly, the sensitivity of the predator population to loss of prey at the given life stage. We here apply a statistical recruitment model for Northeast Arctic cod to evaluate the sensitivity of cod cohorts to loss of zooplankton prey, for example following an oil spill. The calculations show that cod cohorts are highly sensitive to possible zooplankton biomass reductions in the distribution area of the cod larvae, and point to a need for more knowledge about oil-effects on zooplankton. Our study illustrates how knowledge about population dynamics may guide which indirect effects to consider in environmental impact studies.     

基于形态性状的松江鲈鱼(Trachidermus fasciatus)种群鉴别

采用差异系数（C．D）和均数差异显著性这两种数理统计分析方法,对松江鲈鱼的鸭绿江、青龙河和富春江三个群体的表型性状,即85个样本的19项形态性状,其中包括10项可数性状和9项可量性状的差异进行了分析研究。结果表明,这三个群体彼此间的C．D值均小于亚种分化的判定标准1．28的水平,即各群体间的差异尚未达到亚种分化的水平,仍属同一种群。形态性状均数差异显著性的检验结果显示,松江鲈鱼青龙河与富春江两群体之间的差异较小,而鸭绿江群体与这两者的差异相对较大。     

Intermediate-metallicity, high-velocity stars and Galactic chemical evolution

High signal-to-noise ratio spectra were obtained of 10 high-proper-motion stars having  −1 ≲[Fe/H] < 0  , and a comparable number of disc stars. All but two of the high-proper-motion stars were confirmed to have  [Fe/H] > −1.0  , some approaching solar metallicity, but, even so, earlier measurements overestimated the metallicities and velocities of some of these stars. Models of stellar populations were used to assign membership probabilities to the Galactic components to which the high-velocity stars might belong. Many were found to be more probably thick-disc than halo objects, despite their large space motions, and two might be associated with the inner Galaxy. It may be necessary to reassess contamination of previous halo samples, such as those used to define the metallicity distribution, to account for contamination by high-velocity thick-disc stars, and to consider possible subcomponents of the halo.
The change in [α/Fe] ratios at  [Fe/H]≃−1.0  is often used to constrain the degree and timing of Type Ia supernova nucleosynthesis in Galactic chemical-evolution models. [Ti/Fe] values were measured for eight of the high-velocity stars. Both high- and low-[Ti/Fe] halo stars exist; likewise high- and low-[Ti/Fe] thick-disc stars exist. We conclude that the [Ti/Fe]'break' is not well defined for a given population; nor is there a simple, continuous evolutionary sequence through the break. Implications for the interpretation of the [α/Fe] break in terms of SN Ia time-scales and progenitors are discussed. The range of [Ti/Fe] found for high -velocity (low rotation) thick-disc stars contrasts with that for the low -velocity (high rotation) thick-disc sample studied by Prochaska et al.     

Chemistry of springwater in Almora, Central Himalaya, India

 A field study was conducted to assess variations in physico-chemical characteristics of water of the springs located within the boundary of a Central Himalayan town where the springwater is used for drinking purposes. Monitoring of 12 springs was carried out for three seasons (winter, summer and monsoon). The results indicate direct influence of unplanned sewage disposal on the springwater quality as reflected by significant regional variations in the concentration of nitrates, chlorides, sulfates, sulfides and electrical conductivity. Population density varies within the town from 3110 to 14 137 persons/km^–2 and has direct relationship with water quality. Springs located in the densely populated area had higher concentrations of all these compounds. Concentrations of nitrates up to 60 ppm were observed in some springs, making water unsuitable for human consumption. No significant changes were observed in springwater quality during different seasons. Received: 3 February 1995 · Accepted: 27 February 1996     

The metallicity of CM Draconis

We compare observations of the eclipsing binary system CM Draconis (hereafter CM Dra) with synthetic spectra computed using the stellar atmosphere code phoenix . High-resolution infrared spectroscopic observations of six 0.05-μm-wide regions between 1.51 and 2.45 μm, combined with previous work, particularly CM Dra's accurately known surface gravity, enable us to estimate its metallicity using detailed spectral synthesis. We find significant discrepancies between the observed and synthetic spectra throughout most of the region emphasizing the need for higher quality atomic data in the infrared. Nevertheless, the     CO bands beyond 2.3 μm seem to be well modelled and metal-sensitive, and thus high-resolution spectra should be a most powerful diagnostic tool for spectroscopic analyses for M dwarfs and brown dwarfs. The CO bands indicate a metallicity of around −1 dex for CM Dra. This result is supported by observations of two M dwarfs of similar spectral type, GJ 699 (Barnard's star) and GJ 725B. This result supports inferences from previous infrared work, although it does not agree with standard evolutionary models or optical analyses, which both suggest an abundance for CM Dra close to that of the Sun.     

2011年深圳人体舒适度空间分布特征及影响因子分析

利用深圳多个区域自动气象站资料,采用考虑了气温、风速、相对湿度等要素的人体舒适度计算方案,计算了深圳地区的人体舒适度指数以及不同舒适等级天数,分析了城市地形地貌、路网密度和人口密度等因素对人体舒适度的影响。结果表明：深圳地区沿海比内陆舒适,全市全年舒适天数为7-9个月,夏季感觉热的天数约为2-3个月,冬季感觉冷的天数大部分地区为30 d左右。从不同地区人体舒适度指数的日变化特征来看,夏季比冬季更易受地理位置和下垫面等因素影响。地形地貌、海陆分布、城市规划等地理因素对人体舒适度均有一定影响,相关分析表明海拔高度、道路占地面积和人口密度与热-炎热日数呈对数关系。但在深圳的东部人口稀疏和道路占地较小地区也并非舒适宜人,也会出现较多炎热天气,这与该地区年平均风速相对微弱有直接关系。     

Population, income and ecological conditions as determinants of forest area variation in the tropics

The underlying causes of forest area variation were studied by using data from the original forest assessments between 1970 and 1991 of FAO FORIS database representing 477 subnational geographical units in 67 tropical countries. Multiple regression modelling was applied to measure the effects. Five ecological variables were used to control the varying ecological conditions in the subnational units. Three variables were used to control the varying reliability of forest inventory data. Population and income variables were found to be significant factors explaining forest area variation after controlling for ecological variation. In particular population density and income per capita turned out to be significant underlying factors of deforestation. The overall conclusion is that determining the factors behind forest area variation helps explaining the causes of deforestation.