国产bbaaaaa片,成年美女黄网站色视频免费,成年黄大片,а天堂中文最新一区二区三区,成人精品视频一区二区三区尤物

首頁> 外文學(xué)位 >Mapping the world's cities: An examination of global urban maps and their implications for conservation planning.
【24h】

Mapping the world's cities: An examination of global urban maps and their implications for conservation planning.

機(jī)譯:繪制世界城市地圖:研究全球城市地圖及其對保護(hù)規(guī)劃的影響。

獲取原文
獲取原文并翻譯 | 示例

摘要

Since 2000, eight groups from government and academia in both the EU and the US have created global maps that can be used to describe urban areas. Although most share common inputs, they differ by as much as an order of magnitude in their estimates of the total extent of the Earth's urban land (from 0.27--3.52 million sq. km). Based on a new Discrete Global Grid-based system for map comparison, we find inter-map correlations highest in North America ( r¯ = 0.83) and lowest in Asia (r¯ = 0.66). We conduct the first global accuracy assessment focused on urban areas using a two-tiered approach that draws on high-resolution Google Earth imagery and medium-resolution Landsat-based maps. Across a wide range of accuracy measures, spatial scales, and world regions, the new MODIS 500 meter-resolution global urban map has the highest accuracy (aggregate accuracy rank of 1.0), followed by a thresholded version of the Global Impervious Surface Area map (aggregate accuracy rank of 2.7).;Based on an analysis of the MODIS 500 meter-resolution land cover map and the 2007 World Database of Protected Areas, we observe 19,600 sq. km of urban incursions or inholdings in protected areas (PAs); 77 percent within developed countries. A simple spatial model of urban expansion that is driven by several demographic and urban density scenarios predicts a near doubling of urban areas through 2050 (from 0.66 to 1.22 million sq. km). Assuming that PAs have no ability to deter urban encroachment, this urban expansion will threaten an additional 12,000 sq. km of PA, a 61 percent increase over observed incursions. Despite the relative inaccessibility of Africa's PA, by 2050 that region faces the largest potential PA losses: 2,700 sq. km, an increase of 392 percent. Overall, developing countries account for 76 percent of all potential urban PA incursions through 2050. High-growth demographic scenarios combined with declining urban densities yield global PA incursions twice the size of those derived from lower-growth, more compact futures. Our findings highlight the need to account for demographic pressure and urban planning when designing sustainable conservation strategies in the context of a rapidly urbanizing world.
機(jī)譯:自2000年以來,歐盟和美國的八個政府和學(xué)術(shù)界團(tuán)體創(chuàng)建了可用于描述城市區(qū)域的全球地圖。盡管大多數(shù)共享共同的投入,但它們對地球城市土地總面積的估計差異最大(從0.27--352萬平方公里)。基于一個新的基于離散全球網(wǎng)格的地圖比較系統(tǒng),我們發(fā)現(xiàn)地圖間相關(guān)性在北美最高(r = 0.83),在亞洲最低(r = 0.66)。我們使用兩層方法進(jìn)行了針對城市地區(qū)的首次全球準(zhǔn)確性評估,該方法采用了高分辨率的Google Earth圖像和中分辨率的Landsat地圖。在廣泛的精度測量,空間比例尺和世界區(qū)域中,新的MODIS 500米分辨率的全球城市地圖具有最高的精度(總精度等級為1.0),其后是全球不可滲透表面積地圖的閾值版本(總精度等級為2.7)?;趯ODIS 500米分辨率土地覆蓋圖和2007年世界保護(hù)區(qū)數(shù)據(jù)庫的分析,我們觀察到19,600平方公里的城市入侵或保護(hù)區(qū)(PAs)土地。在發(fā)達(dá)國家中有77%。由幾個人口和城市密度情景驅(qū)動的簡單的城市擴(kuò)張空間模型預(yù)測,到2050年,城市面積將增加近一倍(從0.66到122萬平方公里)。假設(shè)保護(hù)區(qū)沒有能力阻止城市入侵,那么這種城市擴(kuò)張將威脅到另外12,000平方公里的保護(hù)區(qū),比所觀察到的入侵增加61%。盡管非洲的PA相對難以接近,但到2050年,該地區(qū)面臨最大的PA潛在損失:2,700平方公里,增長392%??傮w而言,到2050年,發(fā)展中國家將占所有潛在的城市PA入侵的76%。高增長的人口情況加上城市密度的下降,使全球PA入侵的數(shù)量是低增長,緊湊型期貨衍生的全球PA入侵的兩倍。我們的發(fā)現(xiàn)強(qiáng)調(diào)了在快速城市化的世界中設(shè)計可持續(xù)保護(hù)策略時,必須考慮人口壓力和城市規(guī)劃。

著錄項

相似文獻(xiàn)

  • 外文文獻(xiàn)
  • 中文文獻(xiàn)
  • 專利
獲取原文

客服郵箱:kefu@zhangqiaokeyan.com

京公網(wǎng)安備:11010802029741號 ICP備案號:京ICP備15016152號-6 六維聯(lián)合信息科技 (北京) 有限公司?版權(quán)所有
  • 客服微信

  • 服務(wù)號