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1.
Michael Campbell 《Area》2009,41(3):341-349
Avian scavengers are common and active in the social life of southern Ghana, yet few studies consider both the ecological factors for avian presence and the avian–human interactions from human gender and age perspectives, and compare avian behaviour in both human-dominated and natural landscapes. This paper examines interactions between people, hooded vultures and pied crows in Accra and Kumasi, Ghana using both ecological and social research methods. Land use was classified for species presence into meat and waste production, vegetable marketing, non-food production, residential and central business areas, green spaces and rural areas. One hundred and eighty-four people were interviewed, classified according to age and gender. Hooded vultures and pied crows were more common in urban than rural areas, and their presence was positively correlated with human numbers. Birds were most common in meat and waste production areas, but also foraged for street discards in non-food production and residential areas, and were most rare in rural areas. Bird consumption of waste was viewed positively, while eating of other foods, close proximity and unusual behaviours were viewed negatively. Both species, especially the larger vultures, were feared as spiritual agents, this measured by odd behaviours. Women and older people had stronger beliefs, due to cultural conditioning. These human perspectives and reactions influenced avian presence. This study contributes to urban avian ecology, socio-cultural studies and urban planning. 相似文献
2.
Stream Channel Enlargement Response to Urban Land Cover in Small Coastal Plain Watersheds,North Carolina 总被引：1，自引：1，他引：0
《自然地理学》2013,34(6):528-555
Stream channel response to urban land use has not been well documented for southeastern Coastal Plain streams. In this study, urban channel response was evaluated in small Inner Coastal Plain watersheds (<5 km2) in eastern North Carolina. Reaches were selected across a range of watershed total impervious area (0-67% TIA). Channel dimensions and sediment grain size data were collected along 20 urban (>10% TIA) and 20 rural reaches (<10% TIA), and at 10 stormwater outfall sites (180 cross-sections). Urban cross-sectional area, channel incision ratio, and channel grain size (gravel%, D50, and D84) were greater, relative to rural channels. Bankfull cross-sectional areas were approximately 1.78 times greater for urban watersheds than for rural watersheds. Channels in urban watersheds were incised and had median full-channel capacities approximately 3.4 times greater than channels draining rural watersheds. Watershed TIA explained 65-72% of channel capacity enlargement. Urban expansion in the region began in the 1960s, with major urbanization occurring over the last 25 years. Channels draining urban watersheds are still responding to this land use change by downcutting and widening. Urban channel incision has frequently cut off streams from their floodplains, reducing floodplain sediment retention and water quality functions. 相似文献
3.
中国城乡建设占用耕地的时空格局及形成机制 总被引：7，自引：1，他引：6
描绘了1996-2006年间中国城乡建设用地增长及其占用耕地的时空特征,探讨了城乡建设占用耕地的驱动机制。研究发现：人口流动为主的城镇化模式导致农业转移人口在城乡“两头占地”,这是中国城乡建设用地持续扩张的主要根源;各类开发区的设立和扩张都以占用耕地为主,对城乡建设占用耕地的贡献超过一半;而城市和镇的扩张速度更慢、土地来源更为多元。实证结果表明,投资和产出增长的差异性对城乡建设及其耕地占用的时空格局起到了关键作用;中西部地区的基础设施建设占用了大量耕地,但对区域经济发展和人口集聚的带动作用有限;以开发区为载体的产业集聚发展模式有利于中西部地区的土地集约利用和耕地保护,而东部沿海地区的省级开发区则容易成为地方政府的圈地运动。土地集约利用和耕地保护政策应重点解决农业转移人口城乡同时占地的问题,发挥城镇化的节地效应,并强化政策的区域差异性和针对性。 相似文献
4.
Maliha S. Nash Walter G. Whitford David F. Bradford Susan E. Franson Anne C. Neale Daniel T. Heggem 《Journal of Arid Environments》2001,49(4):695
The objectives of this study were to determine if metrics for ant species assemblages can be used as indicators of rangeland condition, and to determine the influence of vegetation and ground cover variables, factors often influenced by livestock grazing, on ant communities. The study was conducted in two areas in the Great Basin: a sagebrush-steppe in southeastern Idaho (n=30 sites), and a salt-desert shrub in western Utah (n=27 sites). Sites were selected based on known rangeland condition (i.e. good, fair, poor) associated with livestock grazing. Ant communities differed considerably between the two study areas. Collectively, more ant species occurred at the Idaho sites (30) than at the Utah sites (21), relatively few species (eight) occurred in both areas, species richness was significantly greater at the Idaho sites (mean=12·0 species) than the Utah sites (mean=6·9 species), and Formica spp. were diverse (total of 15 species) at the Idaho sites but rare (one species) at the Utah sites. In Idaho, all species collectively, generalists, and Formica spp. were significantly less abundant on sites in poor condition than that on sites in good or fair condition, whereas in Utah, seed harvesters and Pheidole spp. were significantly more abundant on sites in poor condition than that on sites in good or fair condition. In Idaho, species richness was significantly lower on sites in poor condition. In Idaho, species richness and relative abundances of several ant groups were significantly related to bare patch size and parameters for cover or species richness of several vegetation groups. In contrast to the comparisons involving sites in poor condition, no differences in ant communities in either Idaho or Utah were evident between sites in good and fair condition. Thus, the ant communities responded only to large changes in rangeland condition and to large differences in climatic/edaphic conditions between the two areas. Hence, ant community metrics appear to have limited utility as indicators of rangeland condition in the Great Basin. 相似文献
5.
6.
基于卫星遥感的北京城乡植物物候差异 总被引：1，自引：0，他引：1
利用2002-2009 年1 km分辨率的MODIS NDVI数据,通过提取春季NDVI上升最快的日期和秋季NDVI下降最快的日期,对比分析了北京地区城市与乡村植物物候的差异。从空间格局和时间演变两个角度,分别对比分析了核心城区、边缘城区和乡村3 个区域的生长季开始日(SOG)、结束日(EOG)以及总日数(TD)3 个物候指标。结果表明,城区的SOG早于乡村,其中核心城区最早,比乡村提前约20 天;城区的EOG晚于乡村,其中核心城区最晚,比乡村推迟约15 天;由此导致城区的TD多于乡村,其中核心城区最多,大约比乡村多35 天。2002-2009 年,城区的SOG呈现推迟的趋势,EOG呈现提前的趋势,而乡村的SOG呈现提前的趋势,EOG呈现推迟的趋势;由此导致城区TD呈现减少的趋势,乡村则呈现增加的趋势。上述结果量化了北京地区城市与乡村植物物候的差异,揭示了城市环境对植物物候的影响,为研究人类活动的生态环境效应提供了实证。 相似文献
7.
The use of rural areas by the urban population is an important organizing principle in the study of the rural hinterland of urban centers. One of the important land uses identified within the urban field is recreation. This paper focuses on cottage property ownership in one part of the urban field, the rural-recreational countryside. Using three case studies from Canada, it was found that cottage properties account for a large proportion of local residential property. Although most cottage properties are owned by urban residents, up to one-quarter are owned by local residents. Using a questionnaire survey, it was also found that cottage owners are more likely to be older, better educated, and have higher incomes than rural residents. 相似文献
8.
建立中国城市的实体地域概念 总被引：91，自引：2，他引：91
本文总结了我国在城市的行政地域与景观地域严重背离的情况下，继续使用行政地域区分城乡的种种弊端，认为解决这一问题于关键在于建立适合中国特点又具有国际可比性的城市实体地域概念，以此作为城乡划分及统计的地域基础，文章提出以下限人口规模、非农化水平和人口密度三个指标定义城市实体地域，并在大量实证研究的基础上，通过对中国城市空间形态的分类，提出了一套完整的划分实体地域的方法和工作程序。 相似文献
9.
Invasive plant species are a growing concern in many regions of the world, yet little information is available on the effects of habitat type and distance to urban settlements on the ability of alien plants to become established. We studied plant communities from the arid steppes to the Andean forest within two national parks and surroundings, in northwestern Patagonia, Argentina. Alien and native vascular plant species were sampled using 90 × 100 m2 plots and analyzed in relation to both climatic and environmental variables and distance to urban centres. We also compared life-forms of alien and native species. Precipitation and distance to an urban centre were important determinants of alien species community richness and composition, and shrubland sites had significantly more alien species than forest or steppe sites. Alien flora (15% of the species) was composed of a higher proportion of annuals and biennials than native flora. Our results suggest that precipitation, distance to source population, and anthropogenic disturbance influence the invasion process in this region, together with the availability of open niches. This work stresses the importance of monitoring invasive species in natural reserves, and of considering habitat types as well as idiosyncratic characteristics of the non-natives for developing management strategies. 相似文献
10.
中国城镇化与经济增长及用水变化的时空耦合关系 总被引：8，自引：1，他引：7
中国的快速城镇化进程伴随着经济总量与用水总量的持续增长以及严重的城市缺水危机,然而三者之间的定量关系及内在机理尚不完全清楚。本文构建了城镇化驱动经济与用水增长的完全分解模型,定量测度了中国以及31个省级行政区1997-2011年城镇化过程对经济增长与用水变化的驱动效应。结果表明：① 中国城镇化对经济增长的综合贡献率长期稳定在30%左右,经济增长60%以上依赖于生产效率的提高,因此应适当弱化“城镇化是经济增长主要动力”的理念;② 中国城镇化虽然通过拉动经济增长增加用水2352×108 m3,但通过优化产业结构和提高用水经济效率减少用水4530×108 m3,中国用水增长的原因是由于人口和经济规模效应而不是城镇化效应;③ 中国东中部的人口和经济大省且处于城镇化加速阶段的,城镇化拉动经济并造成用水增长的作用大,但减量效应也大,而且均呈逐年增长趋势,最终城镇化对用水的综合驱动以减量效应为主,而且在时空变化上的差异相对缩小;④ 城镇化虽有助于减少全国或较大范围区域的用水总量,但会导致城镇建成区或城市群地区的缺水危机,因此应尽快建立并完善城乡之间 (或城镇化水平较高与较低地区之间) 的水资源流转机制与补偿机制。 相似文献
11.
Darkness on the Edge of Town: Mapping Urban and Peri-Urban Australia Using Nighttime Satellite Imagery 总被引：1，自引：1，他引：0
Paul C. Sutton Andrew R. Goetz Stephen Fildes Clive Forster Tilottama Ghosh 《The Professional geographer》2013,65(1):119-133
This article explores the use of nighttime satellite imagery for mapping urban and peri-urban areas of Australia. A population-weighted measure of urban sprawl is used to characterize relative levels of sprawl for Australia's urban areas. In addition, the expansive areas of low light surrounding most major metropolitan areas are used to map the urban–bush interface of exurban land use. Our findings suggest that 82 percent of the Australian population lives in urban areas, 15 percent live in peri-urban or exurban areas, and 3 percent live in rural areas. This represents a significantly more concentrated human settlement pattern than presently exists in the United States. 相似文献
12.
世界遗产缺乏对乡村类型遗产的划分导致对此类遗产特征与综合价值的把握不甚明确。乡村是由其所在地的自然基底要素、硬质要素和软质要素共同作用形成的综合体,记录了乡村人类活动的历史,表达了特定乡村地域的独特精神。文章筛选了28处独立且仍有人类活动的乡村世界遗产,通过梳理文献资料归纳了不同地域的乡村世界遗产特征,并且总结了乡村规划布局、文化艺术、杰出建筑和土地利用4大核心价值。进而指出,我国的乡村世界遗产申遗工作起步较晚,且地域局限、类型单一,未来乡村世界遗产申报可尝试从其他遗产亚类或者双遗产角度开展,发掘乡村地域的自然生态环境、手工业生产方式等价值,丰富我国乡村世界遗产类型和价值。并且,我国在城镇化进程中应当格外注重对乡村世界遗产的保护。 相似文献
13.
以2005年、2010年和2015年甘肃省87个县区、县级市及自治县的工业化、城镇化、信息化、农业现代化与绿色化（简称“五化”）为研究对象,利用空间自相关分析、地理加权回归分析等空间分析方法,结合构建的“五化”协同发展模型,对甘肃省“五化”协同发展的时空分异格局、时空演变趋势和影响因素进行研究分析,以期为甘肃省各市州科学的制定发展政策提供参考。结果表明：甘肃省“五化”协同发展格局具有明显的空间相关性且空间差异显著,协同水平呈现出明显的西北高、东南低分布格局;“五化”发展水平和综合水平较低,协同水平总体不高,以轻度失调、濒临失调和勉强协同为主,但总体上升幅度较大;“五化”协同发展的影响因素,按其影响力大小依次为：农村居民人均可支配收入 > 城乡居民可支配收入差 > 固定资产投资总额 > 财政支出 > 地形起伏度 > 城乡居民消费差 > 降水量。 相似文献
14.
基于多源数据和深度学习的城市边缘区判定 总被引：1，自引：1，他引：0
城市边缘区的定量分析及判定,对城市发展评价和规划,或是城市空间结构研究都具有重要意义。然而现有研究的边缘区判定指标选择过于单一,判定结果过于破碎,城市预设边界、水体及城市绿地对边缘区判定结果干扰大。针对上述问题,从自然、人口、社会经济的视角出发,以遥感影像、人口数据、POI大数据为数据基础,结合深度学习技术,构建基于多源数据和深度学习的城市边缘区判定方法,进行广州市城市边缘区判定及城市结构空间分布特征分析。结果表明：① 此方法能将城市划分为核心区-边缘区-外缘区,判定结果不会受到预设边界范围的影响,且消除了城市内部水体和城市绿地所造成的破碎化;② 城市边缘区与路网耦合良好;③ 广州市的城市核心区空间分布合理。综上所述,此方法能有效检测城市边缘地带,且结果符合实际情况,能为城市规划、政府决策提供参考。 相似文献
15.
Changes in world capitalism caused prices of traditional raw materials to fall and new energy demands to arise at the end of the 19th and beginning of the 20th century. The Andean countries witnessed the fall in the value of their exports and began to receive large flows of foreign investment in mining and industry. Consequently, urban economies were strengthened and demographic patterns were changed. This led to the internal migrations and to a process of social change. These consequences are summarized from relevant studies focusing on Ecuador, Colombia, and Venezuela. Since the 1960s a compendium of information has become available which highlights the causes of the migration, migration patterns, the composition of migratory movements, and the mechanisms that the migrant uses to establish himself/herself in the city. Preston (1969) distinguished 2 migratory patterns in Ecuador: rural to urban, with migratory flows from the rural areas to urban centers and new industrial cities that experienced development and high demand for unskilled labor at comparatively high wages: and rural to rural, based on the movement of population from depressed rural areas to other areas in which programs for colonization or commercial agriculture have been promoted. In a study of Colombia, McGreevey (1968) identifies the lack of cultivatable land, rural violence in certain departments, and other economic and family causes as the principal factors that induced migrations to the cities. The study emphasizes that the predominant model of movement relates to "fill in" migration. The spatial mobility of the Venezuelan Andean population was initially outlined in a voluminous report on economic and social problems of the region (1954). The study indicates that during the intercensal period 1941-50 cities grew much more rapidly than rural "municipos" and that the drive to find employment and earn a living were the most important motives in the movement of peasants to the cities. All of the studies identified that use demographic, economic, or phychosocial approaches have provided partial explanations of the current status of Andean migrations. The explanations they offer, by not transcending the current reality of the migrants, overlook the historical traits of internal migration. Migratory flows do not spring up suddenly. They result from specific socio-political circumstances which, when closely linked to demographic evidence, serve as a basis for understanding the process. Review of studies on internal migration in the Northern Andes, as presented here, reveals a series of distinguishing characteristics: there are 5 migratory patterns--rural to rural, rural to urban, urban to urban, seasonal worker migration, and return migration, and the predominant pattern has been rural to urban; the demographic data show the importance of rural migrants to urban growth in the region and a complementary loss of population in the rural areas; depopulation of the countryside has been selective; and there is a marked disparity in employment remuneration between rural and urban areas. 相似文献
16.
城市热岛效应已对建筑能源需求产生了重要影响,评估城市热岛效应影响下建筑的真实能耗需求及城乡差异对既有建筑的节能调控和未来建筑的方案设计都具有重要意义。论文以天津自动气象站2009—2017年逐时观测数据为基础,应用卫星遥感选站方法,选取天津市区周围4个有代表性的乡村参考气象站,对典型居住建筑全年逐时负荷进行了动态模拟,定量评估了城市热岛强度对不同时间尺度(年、日和小时)建筑负荷的影响。结果表明：① 随着城市热岛强度(IUHI)的增强,城市居住建筑供暖负荷减少、制冷负荷增加,且年平均供暖负荷的减小幅度大于年平均制冷负荷的增加幅度。IUHI每上升1 ℃,城市年平均供暖负荷较乡村减少4.01 kWh/m2、年平均制冷负荷增加1.05 kWh/m2。② 冬季供暖期和夏季制冷期逐日负荷变化表现为：供暖期的高负荷时段主要集中在12月下旬至翌年1月下旬、制冷期为7月下旬至8月上旬,高负荷时段城市日平均供暖和制冷负荷分别较乡村约减少10%、增加6%。③ 日内供暖负荷和制冷负荷小时变化均表现为夜间强于白天。在供暖期和制冷期,北京时间18:00至次日07:00时段无论在城市或是乡村都是高负荷时段;11:00至15:00时段在供暖期是低负荷时段,而在制冷期是高负荷时段,这可能与气温和供暖制冷需求有关。研究表明,应充分考虑小时、日尺度热岛强度对用能的影响,提高供暖和空调运行调控的精细化水平,以期达到降低供暖和制冷能耗的目的。 相似文献
17.
Riparian corridors have the potential to function as thermal refuges, moderating extremes of local temperature variation. However, although demonstrated at individual sites, and over short periods, the consistency of this effect at wider temporal and spatial scales is poorly understood. The aim of this study is to assess the temperature differences between riparian corridors and adjacent non-riparian habitats and to explore the influence of environmental characteristics on these differences. Air temperature was monitored hourly at 20 paired locations (riparian and non-riparian) for two consecutive years. Urban index and canopy cover were characterised by calculating the percentage of impervious surface area and tree canopy cover within a 100 m radius from the centre of each sampling site. Canopy cover reduced summer thermal stresses in both urban and rural areas whereas high urban index tended to increase the daily thermal indices. Rivers had a significant mitigating effect on the urban riparian thermal condition, particularly in extreme hot weather. Riparian corridors were generally 1 °C cooler than non-riparian locations in summer and could be up to 3 °C cooler at some sites in extreme hot weather. Furthermore, riparian corridors at some sites were warmer than non-riparian locations in winter. These findings suggest that the proximity of rivers can modify riparian thermal environments, potentially reducing the heat stress of riparian corridors across landscapes. 相似文献
18.
Peter H. Yaukey 《自然地理学》2013,34(2):149-159
Migratory and resident birds were censused, and their habitat use quantified, during three fall migration seasons in Georgia, USA. The suburban study site was a large cemetery with patches of lawn and shade trees, deciduous brush, mature hardwood forest, and an open pine grove. The frequency of use of different cover types, perch heights, and perch substrates was measured for five resident and four migrant species. All of the migrants used narrower subsets of the available habitats than most or all of the resident species. Three migrants also used habitats that were relatively unused by other species at the site. The frequency of use of different patches of vegetation was measured for seven residents and five migrants. Four of the migrants used narrow subsets of the available patches that were used relatively infrequently by other species at the site. Although three of the migrants heavily used a cover type (deciduous brush) that might be available at most stop-over sites, the red-eyed vireo heavily used ornamental magnolia trees which are probably unavailable at most sites. The narrow habitat and patch use of migrants might reflect reduced intraspecific competition because of the small numbers of each species using the site simultaneously. [Key words: bird ecology, foraging behavior, habitat, migrant birds, resident birds, Georgia.] 相似文献
19.
中国人口收缩的城乡分异特征及形成机理 总被引：2，自引：0，他引：2
在县市尺度上对2000—2010年人口收缩区的城乡分异特征进行分析,划分出城增乡减型、城乡双收缩型和城减乡增型等类型,并建立人口收缩城乡分异的理论分析框架,探讨了不同类型的形成机理,主要的发现如下：① 2000—2010年,人口收缩单元占比约为38.6%,城增乡减型单元占据绝对主体,达到34.5%,而“城乡双收缩型”和“城减乡增型”单元占比均较低。② 中部地区人口收缩区城镇人口增长普遍较快,东北地区城乡双收缩的特征较为突出,而东部和西部地区存在较明显的空间分异。③ 城镇化水平和经济发展水平对人口收缩城乡分异特征的影响最为显著,城镇化水平较高而经济发展水平较低的人口收缩区越可能出现城镇人口增长缓慢甚至城乡双收缩。④ 经济发展速度、人口自然增长水平、公共服务等因素对人口收缩城乡分异特征也存在一定的影响。 相似文献
20.
长江沿线样带土地利用变化时空模拟及其对策 总被引：21，自引：6，他引：21
短时期(几年或几十年)的土地利用变化,主要受社会经济因素的驱动和自然因素的约束。各类土地利用变化基本上都能从与人类生产活动密切相关的耕地和城乡建设用地的变化上得到反映。利用修订后的GTR模型,对长江沿线样带未来30年的土地利用变化进行了模拟。研究发现,东部地区的耕地面积将进一步减少,而全区的耕地和建设用地面积将增加。根据研究区未来土地利用变化的时空特点,提出了相关应对策略,以利于区域土地持续利用的实现 相似文献