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3篇 您的检索式:作者名="Jan SIL"
    题名 作者 年代 出处 被引量
180年来埃塞俄比亚北部高原土地利用/覆被变化(英文)显示文摘Despite many studies on land degradation in the Highlands of Northern Ethiopia, quantitative information regarding long-term changes in land use/cover(LUC) is rare. Hence, this study aims to investigate the LUC changes in the Geba catchment(5142 km2), Northern Ethiopia, over 80 years(1935–2014). Aerial photographs(APs) of the 1930 s and Google Earth(GE) images(2014) were used. The point-count technique was utilized by overlaying a grid on APs and GE images. The occurrence of cropland, forest, grassland, shrubland, bare land, built-up areas and water body was counted to compute their fractions. A multivariate adaptive regression spline was applied to identify the explanatory factors of LUC and to create fractional maps of LUC. The results indicate significant changes of most types, except for forest and cropland. In the 1930 s, shrubland(48%) was dominant, followed by cropland(39%). The fraction of cropland in 2014(42%) remained approximately the same as in the 1930 s, while shrubland significantly dropped to 37%. Forests shrank further from a meagre 6.3% in the 1930 s to 2.3% in 2014. High overall accuracies(93% and 83%) and strong Kappa coefficients(89% and 72%) for point counts and fractional maps respectively indicate the validity of the techniques used for LUC mapping.ETEFA Guyassa Amaury FRANKL Sil LANCKRIET BIADGILGN Demissie GEBREYOHANNES Zenebe AMANUEL Zenebe Jean POESEN Jan NYSSEN 2018Journal of Geographical Sciences2018,28,10:3
2Neonatal cardiac multidetectorrow CT : why and how we do it 显示文摘Tsai IC Chen MC Jan SIL 2008Pediatr Radiol2008,38,40:1
3Neonatal cardiac multidetector row CT:why and how we do it显示文摘Tsai IC Chen MC Jan SIL 2008Pediatr Radiol2008,38,40:1
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