大气气溶胶辐射强迫及气候效应的研究现状   总被引：51，自引：0，他引：51  

罗云峰  周秀骥  李维亮 《地球科学进展》1998,13(6):572-581

由于工业活动的影响,对流层气溶胶含量明显增加。他们通过直接吸收和反射太阳辐射以及改变其它辐射强迫因子（云、臭氧）的大小间接影响地气系统的能量收支。近年来研究表明：人类活动产生的气溶胶具有与CO₂温室气体大小相当、符号相反的辐射强迫效应。他们在全球或区域范围内削弱温室气体的变暖趋势,对气候变化造成很大的影响。文章就人为气溶胶辐射强迫及气候效应近年来的研究状况做了介绍。  相似文献   

文化景观对建构地方集体记忆的影响——以徽州呈坎古村为例   总被引：6，自引：2，他引：4  

孔翔  卓方勇 《地理科学》2017,37(1):110-117

以对黄山市徽州区呈坎古村居民和游客的问卷调查和半结构式访谈为基础,综合运用独立样本t检验和ArcGIS空间分析等方法,分析了文化景观在地方集体记忆建构中的作用。结果显示,无论居民或游客,都对呈坎古村的宗族文化和风水文化形成了集体记忆,而罗东舒祠和水口园林等文化景观则在建构地方集体记忆中发挥了重要作用。但由于与景观接触的方式不同,居民比游客更重视景观的真实性,相对排斥重建和新建的景观,也较少受到导游词的影响;而游客则对景观的真实性不敏感,文化景观和导游解说都可能影响游客的地方记忆。因此,为更好引导对古村落的集体记忆的建构,不仅要重视保护传统文化景观,更要在景观重建或新建过程中尊重居民的建议,争取在居民的传统意识和游客的旅游想象中实现平衡。  相似文献   

Getting to Know Web GIS     

Nicole Kong 《The Cartographic journal》2017,54(2):188-189

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The formation and development of debris flows in large watersheds after the 2008 Wenchuan Earthquake   总被引：2，自引：0，他引：2  

Xiaojun Guo  Peng Cui  Yong Li  Qiang Zou  Yingde Kong 《Landslides》2016,13(1):25-37

The Wenchuan earthquake has caused abundance of loose materials supplies for debris flows. Many debris flows have occurred in watersheds in area beyond 20 km², presenting characteristics differing from those in small watersheds. The debris flows yearly frequency decreases exponentially, and the average debris flow magnitude increases linearly with watershed size. The rainfall thresholds for debris flows in large watersheds were expressed as I?=?14.7 D ^?0.79 (2 h?<?D?<?56 h), which is considerably higher than those in small watersheds as I?=?4.4 D ^?0.70 (2 h?<?D?<?37 h). A case study is conducted in Ergou, 39.4 km² in area, to illustrate the formation and development processes of debris flows in large watersheds. A debris flow develops in a large watershed only when the rainfall was high enough to trigger the wide-spread failures and erosions on slope and realize the confluence in the watershed. The debris flow was supplied by the widely distributed failures dominated by rill erosions (14 in 22 sources in this case). The intermittent supplying increased the size and duration of debris flow. While the landslide dam failures provided most amounts for debris flows (57 % of the total amount), and amplified the discharge suddenly. During these processes, the debris flow velocity and density increased as well. The similar processes were observed in other large watersheds, indicating this case is representative.  相似文献   

A new method of surface subsidence prediction for natural gas storage cavern in bedded rock salts     

Liu Wei  Li Yinping  Yang Chunhe  Jiang Deyi  J. J. K. Daemen  Chen Jie  Kong Junfeng 《Environmental Earth Sciences》2016,75(9):800

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Zircon U-Pb gcochronology and geochemical characteristics of the reshui monzogranite in the eastern kunlun and their tectonic significances北大核心CSCD     

Guo X.-Z.  Jia Q.-Z.  Li Y.-Z.  Li J.-C.  Kong I.-L.  Yang T.  Wang Y. 《矿物岩石地球化学通报》2016,(6):1318-1328

In order to probe the genesis and tectonic significance of the granite in the Reshui area, geoehronologicai and geochemical studies of the Reshui monzogranite have been carried out in this paper. The results show that the Reshui monzogranite has LA-1CP-MS zircon U-Pb age of 231 ±1 Ma, indicating that it was formed in late Triassic. It has high contents of Si()2(68. 74%-7l.69%) , Al,(),( 14. 78%-15. 18%). and k,()( 3. 78%-4. 32% ) , with k,()/Na,() ratios ranging from 1. 05 to 1. 32 ,r Rttmann indexes ranging from 1. 87 to 2. 21 . and A/CNk values varying from 1. 03 to 1. 07, respectively. Thus, the Reshui monzogranite belongs to the high k calc-Alkaline weak peraluminous granite. In addition, it has total REE contents(ΣREE) of I 18. 28x 10-6 - 148. 1 x 10-6, with right declined REE distribution patterns showing strong enrichment of LREE and relative depletion of HREE. Its large ion lithophile elements( L1LE) , including Rb. Ra, Th, and l.REE are enriched, while its high field strength elements( HESE) , including Nh, Ta, P. and Ti, are relatively depleted. It has characteristics of the 1-Type granite. It could be mainly sourced from the partial melting of the subducted slab or basic rocks of the lower crust, mixed partly with mantle materials. Combining with regional geological background, it is believed that the Reshui monzogranite was formed by the interaction of the crust and mantle under the tectonic environment of collision-post collision.  相似文献   

Geo-environmental suitability assessment for agricultural land in the rural–urban fringe using BPNN and GIS: a case study of Hangzhou     

Chunfang Kong  Hai Lan  Guang Yang  Kai Xu 《Environmental Earth Sciences》2016,75(15):1136

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Video Data Model and Retrieval Service Framework Using Geographic Information          下载免费PDF全文

Zhigang Han  Caihui Cui  Yunfeng Kong  Fen Qin  Pinde Fu 《Transactions in GIS》2016,20(5):701-717

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1951~2010年中国年代际累积暴雨时空格局变化的相关因素研究     

史培军  孔锋 《地理科学》2016,36(10):1457-1465

采用多种统计方法,解释1951~2010年中国年代际累积暴雨不断增加的现象。结果表明：快速城镇化因素极有可能是中国大面积暴雨增加的主因。在时间序列上,城镇化因素对中国年际暴雨雨量、雨日和雨强的方差解释分别为61.54%,58.48%,65.54%;自然因子方差解释分别为24.30%,26.23%,21.92%。在空间格局上,中国县级总人口密度和低能见度日数年均值的面板数据与中国年代际累积暴雨雨量、雨日和雨强显著相关,其空间相关系数随年代推移而不断增加,进一步表明快速城镇化因素可能触发了中国年代际大面积暴雨的显著增加。  相似文献   

Contrasting changes in above- and below-ground biomass allocation across treeline ecotones in southeast Tibet     

Xin-sheng Liu  Yu-qin Nie  Gao-qiang Kong  Tian-xiang Luo 《山地科学学报》2016,13(11):2036-2045

Under conditions of a warmer climate, the advance of the alpine treeline into alpine tundra has implications for carbon dynamics in mountain ecosystems. However, the above- and below-ground live biomass allocations among different vegetation types within the treeline ecotones are not well investigated. To determine the altitudinal patterns of above-/below-ground carbon allocation, we measured the root biomass and estimated the above-ground biomass (AGB) in a subalpine forest, treeline forest, alpine shrub, and alpine grassland along two elevational transects towards the alpine tundra in southeast Tibet. The AGB strongly declined with increasing elevation, which was associated with a decrease in the leaf area index and a consequent reduction in carbon gain. The fine root biomass (FRB) increased significantly more in the alpine shrub and grassland than in the treeline forest, whereas the coarse root biomass changed little with increasing altitudes, which led to a stable below-ground biomass (BGB) value across altitudes. Warm and infertile soil conditions might explain the large amount of FRB in alpine shrub and grassland. Consequently, the root to shoot biomass ratio increased sharply with altitude, which suggested a remarkable shift of biomass allocation to root systems near the alpine tundra. Our findings demonstrate contrasting changes in AGB and BGB allocations across treeline ecotones, which should be considered when estimating carbon dynamics with shifting treelines.  相似文献