近40年来气候变化对青海盐湖及其矿产资源开发的影响——以小柴旦湖为例   总被引：2，自引：0，他引：2  

闫立娟  郑绵平  袁志洁 《矿床地质》2014,33(5):921-929

青海是中国盐湖主要分布区之一,蕴藏着丰富的矿产资源。文章以RS和GIS技术为基础,从20世纪70年代、90年代、2000年前后、2008~2009年和2013~2014年五期Landsat遥感影像中提取了青海面积大于10 km2的所有盐湖(不包括干盐湖),分析了其近40年来的变化趋势:总体上,盐湖总面积除在2000年前后有所减少外,基本上呈现增加的趋势;具体而言,2000年前后,萎缩的盐湖主要分布在柴达木盆地;其他时期均呈现全面扩张的趋势。在全球气候变暖的大背景下,通过分析青海地区11个气象台站的年平均气温、年降雨量和蒸发量数据,可知青海地区气候呈现了向暖湿方向转型的趋势,且2002年之后更为明显。最后,以青海省小柴旦湖为例,分析了湖泊淡化、矿产资源贫化对盐湖资源开发的影响,具体为:1资源开发成本升高、难度加大,甚至使一些处于工业开发临界品位的盐湖失去开发价值;2盐湖淡化条件下,锂等矿产资源有效提取技术亟待研发;3政府制定矿产资源开发政策时,需要对气候及盐湖的动态变化过程综合考虑。以上说明,青海地区的暖湿气候使盐湖大幅度淡化,给盐湖矿产资源开发带来了新的挑战。  相似文献   

Remote sensing-based analysis of the planform changes in the Upper Amazon River over the period 1986–2006     

《Journal of South American Earth Sciences》2014

An analysis of the planform changes of the Colombian reach of the Amazon River was carried out over a period of 19.9 years. Remote sensing image processing techniques were applied to Landsat images acquired in 1986, 1994, 2001 and, 2006. These images were selected based on minimal daily water level variations, while providing the widest temporal span. Plan view river changes and geomorphologic characteristics were examined to identify which channel pattern classification best represents this large tropical river system. Discharge was also analyzed to determine whether changes in the river's plan view are a direct response to variations in discharge. The system had a depositional tendency between 1986 and 2006, with a period where erosion was more intense than deposition between 1994 and 2001. Percent change in the plan view area of the system (1.4% yr⁻¹) and the maximum migration rates (125 m yr⁻¹) suggest that this reach of the Amazon is less active than reaches upstream and the downstream reach between the confluences of the Jutaí and Japurá Rivers. Variations in discharge appear to be responsible for deposition and erosion dynamics observed after this remote sensing analysis in the Colombian reach of the Amazon River. Characteristics including multiple channels with vegetated islands developed from within-channel deposition, meandering planform, lateral activity of channel margins, and the absence of islands with saucer-like morphology suggest a multichannel, meandering pattern for this reach of the Amazon, that corresponds to a laterally active anabranching river.  相似文献   

芦山地震同震和震后地表形变及重力变化的理论模拟          下载免费PDF全文

邓明莉  孙和平  徐建桥  祝意青 《地球科学》2014,39(9):1373-1382

为了研究芦山地震的孕震过程和震源区的长期构造过程以及解释实测的震后形变和重力资料, 采用分层介质模型, 利用数值模拟的方法, 考虑区域流变系数, 计算了地震引起的地表同震、震后的形变和重力变化以及区域内部分GPS与重力连续观测台站的震后形变和重力变化的时间序列.结果表明: 芦山地震的地表同震形变显示出发震断层明显的逆冲特性; 粘弹性松弛效应引起的震后地表形变和重力变化比同震形变和重力变化的范围明显扩大, 但随着粘滞系数的增加, 变化量明显减小; 观测台站的震后变化时变曲线显示震后形变和重力变化在震后50 a间变化显著, 100 a后基本平缓, 趋于稳定; 模拟计算的GPS台站中除了MEIG台和MYAN台以外, 其余台站的震后观测必须考虑粘弹性松弛的影响.   相似文献   

Research on quantitative assessment of climate change risk at an urban scale: Review of recent progress and outlook of future direction     

《Chemie der Erde / Geochemistry》2014

Cities are not only major contributors to global climate change but also stand at the forefront of climate change impact. Quantifying and assessing the risk potentially induced by climate change has great significance for cities to undertake positive climate adaptation and risk prevention. However, most of the previous studies focus on global, national or regional dimensions, only a few have attempted to examine climate change risk at an urban scale and even less in the case of a recent literature review. As a result, a quantitative assessment of climate change risk for cities remains highly challenging. To fill this gap, the article makes a critical review of the recent literature on urban-scale climate change risk assessment, and classifies them into four major categories of studies which jointly constitute a stepwise modelling chain from global climate change towards urban-scale risk assessment. On this basis, the study summarizes the updated research progresses and discusses the major challenges to be overcome for the seamless coupling of climate simulation between different scales, the reproduction of compound climate events, the incorporation of non-market and long-lasting impacts and the representation of risk transmission insides or beyond a city. Furthermore, future directions to advance quantitative assessment of urban-scale climate change risk are highlighted, with fresh insights into improving study methodology, enriching knowledge of climate change impact on city, enhancing abundance and accessibility to data, and exploring the best practice to provide city-specific climate risk service.  相似文献   

不同压实度荆门弱膨胀土的一维膨胀-压缩特性   总被引：1，自引：0，他引：1  

周葆春  张彦钧  汤致松 《岩土力学》2014,35(5):1275-1283

为探讨压实膨胀土的体变行为,以荆门弱膨胀土为研究对象,借助高压固结仪对6种制样压实度下的膨胀土试样进行了一维无荷载膨胀和含一次卸载-再加载循环的压缩试验。基于膨胀试验结果,构建了膨胀时程方程,通过参数分析,明确了方程参数的物理意义,并建议了膨胀时程曲线3阶段的划分方法。基于压缩试验结果,探讨了固结屈服应力、压缩指数Cc、回弹指数Cs、膨胀力与制样压实度、土体结构性、膨胀势、孔隙比的相关关系。试验结果及其分析表明,膨胀土体积变化是膨胀势与外部荷载、湿度变化的耦合作用结果,且具有强烈的水-力路径依赖性。  相似文献   

Climate Change and Geochemistry May Explain the Finding of Marine Cyanobacteria in a Continental Saline Lake     

Zorigto NAMSARAEV  Vladimir GORLENKO  Boris KUZNETSOV  Bair NAMSARAEV 《《地质学报》英文版》2014,88(Z1):158-159

正1 Introduction Alkaline Lake Khilganta located in a steppe zone of South Siberia(N 50°42'535,E 115°06'086)is unique among adjacent lakes because of a development of a thick(up to 3 cm)cyanobacterial mat dominated by  相似文献   

Salt Desert and Saline-Ackaline Mixed Dust Storms:An Ignored Issure for Global Climate Change     

SONG Huailong 《《地质学报》英文版》2014,88(Z1):196-197

正Salt desert,saline-alkaline dust storm and saline-alkaline mixed dust storm are significant but ignored problems for a long time.After many years of observations and researches,the author believes that salt desert,saline-alkaline dust  相似文献   

A Preliminary Study of Holocene Climate Change and Human Adaptation in the Horqin Region     

MU Yan  QIN Xiaoguang  ZHANG Lei  XU Bing 《《地质学报》英文版》2014,88(6):1784-1791

Abstract: Human activity during the Holocene in the Horqin region, northeastern China, has been widely documented. As an important proxy record of human activity, black carbon (BC) in sediments has been linked to climate change and human adaptation. A loess-paleosol section located in south Horqin was chosen for this study. Holocene climate change and human adaptation to the environment were discussed by analyzing BC, organic carbon (OC) and other proxies. The conclusions included: (1) before 3900 cal BP, human activity was closely related to the natural environment and cultural development was dominated by climate change. For example, the rapid decline of the agrarian Hongshan culture was caused by a slight decrease in temperature at ~5000 cal BP; (2) during 3900-3200 cal BP, the heavy dependence of human societies on nature gradually lessened and the ability of those human societies to adapt to the environment was enhanced. However, the farming-dominated Lower Xiajiadian culture was nonetheless replaced by the pastoralist Upper Xiajiadian culture due to an extremely cooling event at ~3200 cal BP; (3) during the late Holocene period, the marked influence of climate change on human activity might have lessened as a result of a clear improvement in human labor skills. After this, human living styles were influenced by cultural developments rather than climate change because humans had mastered more powerful means of productivity.  相似文献   

福建新建港口铁路工程地质勘察若干问题探讨     

吴晓东 《福建地质》2014,33(4):293-299

根据福建沿海湄洲湾、江阴、可门3条支线港口铁路的工程地质条件、水文地质特征,综合分析认为在工程施工过程中局部出现不良地质现象,主要有软土、块石填土、不均匀地基、地下水的腐蚀性等.总结在施工过程中因工程地质问题导致的设计变更及处理措施.  相似文献   

中国历史时期气候变化影响及其应对的启示简     

Ge Quansheng  Fang Xiuqi  Zheng Jingyun 《地球科学进展》2014,29(1):23-29

The social impact of global climate change is one of the hotspots in the current research. To deal with the challenges from climate change, it could be learned from the adapting experiences and lessons to climate change in the history. The main achievements of cognition on the historical impacts of climatic change in China and on coping with the climate changes in the future based the published papers in recent years is summarized. The followings are the main conclusions. ①The general characteristics of the impacts of climatic change in the history was negative in the cold periods and positive in the warm periods, but there were regional differences in the impact and responses. ②The cooling trend on centurial scale and the social economic decline run concurrently. The rapid development supported by better resources and environment in the warm period could lead to the increase of the social vulnerability when the climate turned to the cold period. ③Strategies and policies to cope with the climate change in the history were adopted according to the temporal and spatial circumstances and the subjects. Initiative adaptation promoted by governments was an effective way.  相似文献