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991.
B. Mamtimin A.M.M. Et-TantawiD. Schaefer F.X. Meixner M. Domroes 《Journal of Arid Environments》2011,75(11):1105-1113
According to trend computations at three stations each in Sahara desert (Libya), characterized by a “hot” desert type (“BWh”, according to the Koeppen climate classification), and in Central Asia (Xinjiang, China) identified as a “cold” desert type (“BWk”, after Koeppen), increasing annual temperatures were detected over the period 1955-2005 corresponding with global temperature warming. From 1955-1978, negative (decreasing) temperature trends were, however, observed at all three hot desert stations and at two of the three cold desert stations. From 1979-2005, strikingly positive temperature trends were seen at all six stations. In seasonal respects, winter (December to February) and summer (June to August) show different temperature trends over the period 1955-2005: the hot desert experienced an increasing temperature trend at a greater extent in summer than in winter; vice-versa, in the cold desert positive trends were computed for winter and negative for summer. It can also be observed that mostly hot desert warming occurred in summer, opposite to cold desert warming in winter. 相似文献
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994.
西北干旱区耕地扩张原因的实证分析 总被引:7,自引:1,他引:6
近10余年来,在全国耕地面积持续减少的背景下,西北干旱区的耕地面积却明显增加.区域耕地的这一逆向变化,不仅改变了中国的耕地分布格局,同时也加剧了西北干旱区的水资源冲突和荒漠化进程.现有研究中,西北干旱区的耕地扩张往往被理解为区域人口增长、技术进步、政策激励的结果,但这些认识主要来自于统计相关分析和经验判断,还缺乏必要的... 相似文献
995.
The essential purpose of the Convention Concerning the Protection of World Cultural and Natural Heritage is to protect the integrity of heritage values. Outstanding landscape is the core embodiment of the aesthetic value of a
natural heritage site. This paper proposes a new assessment method from the point of view of the protection of heritage values.
It is used to measure the degree of outstanding landscape integrity under the human and natural impact in natural heritage
sites. This paper employ three indices, a visual index of outstanding landscape, a harmony index of the artificial landscape
and a disturbance index of damaged landscape, to measure the impact of landscape integrity. The impact assessment model is
based on a weighted combination of the three indices. The study site is the Fairy Valley, Kanas Nature Reserve, Xinjiang Uygur
Autonomous Region in northwest China. The information employed is derived from field investigation and a Digital Elevation
Model (DEM). A comprehensive evaluation of the Fairy valley was undertaken and it was determined that the outstanding landscape
values are being compromised. Three protection methods are proposed to reduce the adverse effects and maintain landscape quality,
thereby providing site managers with suggestions for the protection of natural heritage values. More broadly, the paper contributes
novel methods of landscape assessment applicable to natural protected areas. 相似文献
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早石炭世巴塔玛依内山组为一套陆相火山岩,下部以基性熔岩为主,上部以中酸性、酸性火山碎屑岩为主.岩石地球化学研究表明,区内火山岩呈高铝玄武岩-安山岩-英安岩-流纹岩钙碱性系列的演化趋势.从基性岩到酸性岩稀土模式相似,但铕负异常愈加明显.火山活动与金银矿成矿关系密切,玄武岩类、火山碎屑岩类Au、Ag、As含量较高,可能是成矿物源. 相似文献
998.
郝毓灵 《中国地理科学(英文版)》1997,7(3):251-258
TheimportantgUidingprinciplethatenstiresthesustainabledevelOPmentOfChinais"The21stCentury'sAgendaofChina"(Office,1994).ThesustainabledevelopmentintheareasalongthenewEtirasiancontinentalBridge(sectioninXinjiang)belongstooneoftheprioritemsof"theagenda".TheopeningofthenewEtirasiancontinentalBridgenotonlybringsabbotgreatoPPOrtunitiesfordevelopmentofXinjiang,butalsoplaysamajorroleinreducingthegapbetweentheWesternandeasternpartsofChina.Furthermore,itcantriggerfuttiresustainabledevelOPmentin… 相似文献
999.
新疆棉花基地布局研究 总被引:2,自引:0,他引:2
新疆棉区是我国正在开发建设的优质棉花基地。本文阐述了新疆棉区在我国的战略地位,从自然生态和社会经济诸因素分析评价了新疆棉花生产的利弊条件,探讨了新疆棉花基地的发展方向和远景规模,划分了新疆棉花生产的适宜区和经济区,并在此基础上提出新疆棉花基地区域布局的设想。 相似文献
1000.