排序方式： 共有144条查询结果，搜索用时 15 毫秒
51.
Global patterns in urban green space are strongly linked to human development and population density
Urban green space is important for alleviating high temperatures, pollution, and flooding in cities. Furthermore, it is becoming increasingly clear that urban green space is important for the mental and physical health of humans residing in cities and that urban green space may harbor unique biodiversity. Understanding the extent and drivers of urban green space is thus important. While urban green space has been mapped and studied at local to national scales, the global patterns and drivers of urban green space remain unknown, potentially hampering effective planning and allocation of resources toward reaching sustainable development goals. Here, we quantified the effect of environmental and socio-economic drivers (temperature, precipitation, human development, and population density) on urban green space globally by focusing on national capital cities. We used satellite imagery to map urban green space using two measures: the Normalized Difference Vegetation Index (NDVI), and the fractional cover of “green” land cover classes. NDVI is useful as it includes all vegetated surfaces, also small ones like gardens. However, land cover classes allow the exclusion of certain classes such as sports fields or cropland. We used boosted regression trees to show that climatic variables accounted for 75 % of the relative influence in urban green space, with a positive effect of precipitation and a negative effect of temperature. Importantly, socioeconomic variables accounted for 25 % of the influence on global urban green space, with a positive effect of human development index (HDI) and a negative effect of population density. HDI in relation to urban green space has not previously been tested globally, and our study shows that significantly affects urban greenspace. The results demonstrate that cities where development status is low and population densities are high, typically in the Global South, have less urban green space than the climate would predict. The results therefore suggest that human wellbeing does not only benefit directly from increasing human development and decreasing population densities in urban areas, but that these effects may be compounded by also improving nature’s contribution to people. 相似文献
52.
[目的]探究珠三角植被覆盖度空间分布和时空变化的驱动力,为该地区生态环境的保护提供科学参考。[方法]基于Landsat 5 TM和Landsat 8 OLI数据,利用像元二分模型反演珠三角2000,2005,2010,2015和2020年5个时期的植被覆盖度,分析珠三角植被覆盖度的空间格局和时空变化的过程。并结合5个时期的年降水量、年均温度、人口密度和土地利用,采用相关系数和地理探测器等方法开展研究。[结果](1)珠三角植被覆盖度在空间上表现为中部较低,边缘区域较高的分布格局,在佛山市、中山市、珠海市、广州市西南部、东莞市和深圳市较低,肇庆市、江门市和惠州市较高。植被覆盖度总体上表现为改善的趋势,改善的面积比例为64.99%,在时间上存在阶段性的差异,2010—2015年期间高植被覆盖度(80%以上)增长的面积最明显;(2)影响因素对植被覆盖度的驱动有明显的区域差异性,年降水量和土地利用程度起抑制作用的面积大于起促进作用的面积,年均温度和人口密度起促进作用的面积大于起抑制作用的面积;(3)植被覆盖度空间格局因子探测表明土地利用程度的解释力最强,交互探测表明年均温度与土地利用程度交互作用... 相似文献
53.
The importance of greenery in urban areas has traditionally been discussed from ecological and esthetic perspectives, as well as in public health and social science fields. The recent advancements in empirical studies were enabled by the combination of ‘big data’ of streetscapes and automated image recognition. However, the existing methods of automated image recognition for urban greenery have problems such as the confusion of green artificial objects and the excessive cost of model training. To ameliorate the drawbacks of existing methods, this study proposes to apply a patch-based semantic segmentation method for determining the green view index of certain urban areas by using Google Street View imagery and the ‘chopped picture method’. We expect that our method will contribute to expanding the scope of studies on urban greenery in various fields. 相似文献
54.
沈美萍 《农业图书情报学刊》2007,19(7):29-30
通过阐明Google相关模块的功能和数字图书馆情形下参考咨询工作的特点,提出参考咨询工作在面临Google挑战情况下的对策。 相似文献
55.
介绍了google搜索引擎。并着重从人性化服务、特色服务2个方面探讨了google搜索引擎的特点,并进行了简要的评价。 相似文献
56.
Google图书数字化计划带来的思考 总被引：1，自引：0，他引：1
张丽宁 《农业图书情报学刊》2006,18(12):139-141
介绍了Google图书数字化计划背景、发展以及欧洲的反映,此举引发的一系列争议,以及我们拟采取的对策。 相似文献
57.
58.
阐述了将Google Earth提供的免费卫星图片作为数据源的方法,并利用CorelDraw软件绘制具有一定精度的农业专题图。 相似文献
59.
基于Google Earth的黑龙江省林火信息系统的开发与实现 总被引：1，自引：0，他引：1
通过面向对象的编程语言,以黑龙江省森林防火信息系统的开发与实现为例,探讨了基于Google Earth的二次开发构造的具体步骤与方法,为利用Google Earth来构建森林防火GIS系统提出了一种新的思路与方法. 相似文献
60.
向阿媚 《农业图书情报学刊》2011,23(7):124-126
论述了个性化定制服务的概念、特点以及个性化定制实现的技术,并着重探讨了Google个性化定制服务在学术研究中的应用。 相似文献