干旱区引水渠道渗漏补给能力实验研究

针对干旱区山前倾斜平原地层透水能力强、地下水埋深大、补给水源水质普遍较好、泥沙含量高等特点,对渠道渗漏补给能力进行实验研究,寻求适合干旱区特点的快速高效、经济可行并且能够长期运行的地下水人工补给方案。研究结果表明:引水渠道采用下部混凝土板防渗、上部干砌石防渗以增加渠道渗漏量的人工补给地下水方式是可行的。     

干旱地区冻结滞水的形成及其在造林中的应用

为探索干旱地区冰结滞水形成及融化规律,经室内冰融模拟试验结果表明,在冰结势作用下包气带水和空气中水分以液态和气态向冰结滞水层迁移富集,含水率比冰结前增加１１．１％￣１４．７５％,主要富集在０￣２０ｃｍ的深度,形成倒置富水性。在解冻期间由上向下融化,融水以蒸发为主消耗。部分向下运动,可见,冰结滞水是干旱区技术等植物越冬春季繁衍不可缺少的水资源,应用冰结滞水的理论和动态规律。采用科学的技术措施,提高其     

干旱生态环境及水资源对全球气候变暖响应的研究进展

西北地区现代气候变化基本特征是冬暖夏干,采用脆弱度和影响指数方法定量评价了生态环境对全球气候变暖响应,重点阐述了西北现代气候变化对干旱生态环境和水资源这两个领域的影响.结果表明: 由于现代气候变干变暖的自然和人为因素的共同作用,导致我国西北地区的黄土高原、黑河流域、石羊河流域、甘南高原和黄河首曲的地域生态环境有不断退化的趋势.气候变干使渭河上游、黄河上游(洮河和大夏河)以及黄土高原中部7条主要河流的径流量呈明显下降趋势,引起水资源短缺.     

A Study of Global Change Population and Economic System Risk Forming Mechanism and Assessment

Global climate change featured with warming has created serious challenge to world sustainable development and human security. It has become an important consensus of the international society to assess global change risk at the global scale and carry out tailored governance and risk-based adaptation. National Key Research and Development Program “Study on global change population and economic system risk forming mechanism and assessment” aims at quantitatively predicting future global climate change and population and economic system exposure and vulnerability change, developing global change population and economic system risk assessment model based on complex system dynamics, synthesizing risk assessment model with proprietary intellectual property rights, assess global change population and economic system risk of the near and mid future at the global scale, and compiling the atlas of global change population and economic system risk. The outcomes intend to serve the participation of global risk governance and international climate negotiation, and to provide scientific support to the implementation of international disaster risk reduction strategy.     

运城市高铬地下水的分布及成因分析

本文通过对运城市高铬（Cr^6＋）地下水分布规律及成因的探讨，确认高铬（Cr^6＋）地下水的分布是自然原因形成的。提出了地下水中Cr^6＋的来源分为外生来源和内生来源两个方面，并详细地揭示了区内高铬地下水的形成机理。     

盆地内大面积砂体分布的一种成因机理--干旱气候下季节性河流沉积

我国西部新疆地区侏罗系-下白垩统大面积、厚层状砂岩油气勘探获得了重大发现, 大面积厚层状砂体及泥岩红层沉积的成因机理受到长期关注。结合现今准噶尔南缘多条季节性河流的沉积体系、砂体展布特征分析, 并对比郝家沟-头屯河剖面、玛纳斯河剖面上侏罗统齐古组、喀拉扎组的岩相组合、岩石颜色、砂泥岩沉积构造、沉积序列与古环境分析, 认为干旱气候下头屯河组上部-喀拉扎组的季节性曲流河-季节性辫状河沉积是上侏罗统大面积厚层状砂砾岩体及厚层状泥岩红层沉积的重要成因机理, 进而建立了季节性河流的砂体构型和成因模式。准噶尔盆地南缘季节性河流沉积砂体构型和成因模式的建立, 对进一步认识我国古代季节性河流沉积提供了有益参考。     

Climate Change and Silk Road Civilization Evolution in Arid Central Asia: Progress and Issues

Arid central Asia is one of the regions most sensitive to global climate change, as well as the region with dramatically hydrological changes and fragile ecosystems. The region includes the main body of the ancient Silk Road, which played a key role in the cultural exchange and the rise and fall of Silk Road civilization. Scientific assessment of the risks faced by the sustainable development of human society in the arid central Asia under the background of global warming is a major scientific issue that has received much attention. The study of the relationship between cultural exchange, development of Silk Road civilization and climate change can provide a scientific basis for understanding the evolution rules of human-land relationship on different timescales in this area. This study summarized the research progress in the history of cultural exchanges, the rise and fall of Silk Road civilization, climate change during the Holocene, forcing mechanisms of climate and hydrological change on different timescales, as well as the process and rule of human-environment interaction. On this basis, we proposed that the study of the temporal and spatial patterns of Holocene climate change and the evolution of Silk Road civilization in arid central Asia, as well as the research on the interaction mechanisms between human and environment, are obviously insufficient. Solving the problems of regional imbalance of climate change and cultural evolution in arid central Asia and strengthening the cross-disciplinary study of geoscience and archaeology are effective ways to promote the study of climate change and changes of Silk Road civilization, which has important scientific and practical significance for understanding the evolution of human-land relations in the region, coping with the challenges of climate change, and serving the “One Belt, One Road” strategy.     

Pleistocene Loess-Paleosol Sequences in Arid Central Asia State of Art

Loess of central Asia is located in a linkage zone between the European and Chinese loess depositional belts. Paleoclimate signatures from loess-paleosol sequences here is a key for completely understanding the spatial-tempo paleoclimate changes of Euro-Asia and for understanding the interactions between westerlies and Asia monsoon system during geological time. However, paleoclimate investigations of loess-paleosol sequences in arid central Asia is relatively weak than those from Europe and Chinese Loess Plateau. Specific, correlations of paleoclimate records with Chinese loess is required for better understanding “westerly regimes” in central Asia and its phase relationship with monsoon Asia on various time scale. In this work, we reviewed new advantages of loess study in central Asia during the last decades. Based on the stratigraphic and paleoclimatic correlations of loess-paleosol sequences between central Asia and the Chinese Loess Plateau, we discussed aridification history of Asia on tectonic time scale, the hydroclimate changes in arid central Asia and its phase relationship with Monsoonal Asia on orbital and millennial time scale during the Pleistocene.     

Temporal-spatial Distribution of Suitable Areas for Major Food Crops in China Over 60 Years

Simulating the temporal-spatial distribution of areas suitable for crops is an important part of analyzing the effects of climate change on crop growth, reducing the vulnerability of crop growth, and assessing the adaptability of crop growth to climate change. This study selected climate factors that affect the growth of wheat, maize and rice, and it combined surface soil and ground elevation factors as environment variables, as well as data from agricultural observation stations as species variables. The MaxEnt ecological model was used to identify suitable areas for these three crops during the period of 1953-2012. The areas suitable for the three crops were analyzed to determine the temporal-spatial distribution of major food crops and to estimate the difference in crop growth adaptability under climate change. The results showed the following: \mathrm{①} The response to climate change of the areas suitable for food crops could be ranked from strongest to weakest as follows: wheat, rice, and maize. \mathrm{②} On the same space-time scale, for the growth of wheat and rice, the southern agricultural regions, mountainous areas and plateaus were relatively unsuitable for a wider variety of crops than the northern agricultural regions, plains and basins. \mathrm{③} The adaptability of wheat increased in the major agricultural regions slightly. The adaptability of maize increased in the northern agricultural regions and decreased in the southern agricultural regions, respectively. The adaptability of rice was stable in the southern agricultural regions, and it decreased in the Huang-Huai-Hai region and increased in the northeastern region. \mathrm{④} Over 60 years, the ability of the major food crops to adapt to climate change increased in the northeast region, Gansu-Xinjiang region, Southwest region and Loess Plateau region, but the adaptability of major food crops decreased in the Huang-Huai-Hai region and the Mid-and-Lower Reaches of the Yangtze River. \mathrm{⑤} The suitable areas of maize and rice were significantly correlated with planting areas and yields, respectively, which provided feasibility for simulating the distribution of suitable areas on maize and rice in different climate scenarios in the future. The suitable area of wheat is not significantly related to the planting area and yield. In the future, we will take more factors to model the suitable area of wheat accurately.     

西北干旱区近50年气候变化特征与趋势

20世纪后期全球增暖趋势越来越明显，受全球增暖的影响，西北地区的气候也将受到不同程度的影响。选取了西北干旱区1951-2000年的21个代表站点气温、降水量资料，采用趋势系数法对西北干旱区近50年气温和降水变化进行分析，找出各分区的变化趋势。结果表明：近50年西北干旱区气温呈上升趋势（0．22℃／10a），1986年后气温明显升高；柴达木盆地和新疆北部升温较大；各季都有增温趋势，贡献最大的是秋冬两季。降水变化有增加的趋势（3．2mm／10a），年降水量贡献最大的是夏季；各区降水都有增加，其中新疆北部降水增加最多。西北干旱区近50年气温升高趋势是南北高，中间低；降水量增加趋势从东南向西北呈现递增的格局。     

辽宁翁泉沟橄榄玄武岩的地质地球化学特征及其形成环境

辽宁凤城翁泉沟橄榄玄武岩是翁泉沟硼镁铁矿的一种容矿岩石,它具裂谷环境下火山岩的特征:①带状分布,整合于早元古代的火山-沉积地层中,具气孔杏仁构造;②主量元素具富铁富镁的特点;微量元素中B、Cl、F、Rb、Cs、Th和U等含馈较高;V,Cr,Ni等相对低些;高场强微量元素含量与相关比值与一般基性岩相似;Ti、Zr、Cr、Y等微量元素相互关系图解显示其原始岩浆具有板内玄武岩的特点;稀土分配型式明显向右倾斜,基本不显铈、铕异常,显示岩浆没有经过明显的分离结晶过程;③本区的橄榄玄武岩与同-硼矿成带上的营口大石桥后仙峪的镁橄榄岩和宽甸地区砖庙的镁质大理岩属于同-地层层位,都具富镁特征,都足辽东硼矿的镁质容矿岩石,它们在成因上具有内在联系,其稀土总量对比,显示它们同属大陆裂谷环境下岩浆活动的产物.     

芒崖凹陷干旱气候背景下网状河流沉积体系及演化

通过对柴达木盆地芒崖凹陷上新统露头的结构单元分析和对钻井剖面上砂岩、泥岩的空间分布关系及岩相转换的Ｍａｒｋｏｖ链模式等方面的研究,得出研究区中－上新统是网状河流沉积体系并在上上新统转化为瓣状河流沉积体系这一新认识。孢粉化石资料、深干裂以及钙质结核等指示网状河流发育姑干旱气候背景下。网状河流向瓣状河流的演化受到盆地基底的沉降速率及与气候密切相关的植被覆盖程度等因素的控制。     

内蒙古磴口河湖相沉积物正构烷烃分布特征及其环境意义

为了探讨季风边缘区气候变化特征,对内蒙古磴口一个深15m 的钻孔沉积物中的正构烷烃进行了分析.结果显示,正 构烷烃总体呈现出以高碳数为主的分布特征,表明其主要来源于陆生高等植物,多数样品以nC27、nC29为主峰,奇碳优势明 显,局部样品以nC25为主峰,显示了流域植被类型为木本植物和少量水生植物.但在钻孔上部短链正构烷烃相对丰度较高,主 要以nC18为主峰,无明显的奇偶优势,反映了低等藻类生物增加.正构烷烃的分布特征在沉积钻孔中表现出的多阶段变化,与 岩性、有机碳同位素等变化相吻合,反映出研究区寒暖交替的气候条件.      

准噶尔盆地西泉地区石炭系火山岩型油藏形成及分布

准噶尔盆地西泉地区在构造上位于北三台凸起西斜坡,是有利油气聚集区。虽然已取得了一些勘探成果,但该区油藏控制因素复杂,纵横向分布规律认识不清,致使探明程度低、勘探难度大。利用钻井、测井、录井、试油、岩芯分析化验等资料,结合地震资料,查明了该区石炭系储层岩石学特征、储层特征。研究结果表明:西泉地区石炭系火山岩主要为火山熔岩类、火山碎屑岩类;火山岩储层物性北部较差,南部较好,有利储层主要是喷发相火山角砾岩、溢流相安山岩、英安岩等。该区油藏分布的主要控制因素:1)垂向上油藏主要分布于风化壳附近; 2)岩性的侧向变化控制了油藏的平面分布范围; 3)不整合面的发育与油藏的分布关系密切。进一步阐明了研究区油藏的分布规律,油气主要聚集于不整合面附近,且呈北东南西向条带状分布。油层的纵向分布与不整合面的风化淋滤带的深度有关,南北差异较大,储层的非均质性影响油藏的连片分布。     

干旱半干旱区CO2浓度升高对生态系统的影响及碳氮耦合研究进展

大气CO2浓度升高已成为全球备受关注的环境问题.CO2排放量的增加加剧了地球表层的温室效应,也对生态系统的结构和功能产生了重要影响.生态系统对CO2浓度升高的响应是一个长期的过程.在干旱半干旱区,CO2浓度的升高对生态系统生产力、植物、土壤和微生物等都有影响,尤其改变了生态系统中的碳循环,并加剧了生态系统对氮的需求.碳...     

Spatio-temporal Distribution of Famine and Its Relationship with Climate,Disaster, Harvest in North China During 1736-1911

Based on records on famine kept in historical documents, 2950 famine events counted with “county time” in North China during 1736-1911 were collected, and annual famine index series in North China was reconstructed using weighted average method according to the severity of famine. Spatio-temporal distribution of famine and its relationship with climate, disaster and harvest was analyzed. The research shows that variation of temperature and precipitation has significant negative correlation with poor harvest and famine. The drought has a more significant correlation with harvest and famine than flood. In 1736-1795 when was at the peak of the Qing dynasty, the sensitivity of poor harvest and famine to drought was significantly lower than in 1796-1911 when was in decline, because effective social response to disaster could reduce the risk of poor harvest and famine. Using the kernel density estimation method, three main high risk areas of famine were indentified: Fen River Valley in south Shanxi Province, south-central He'nan Province, and the junction of Hebei, Shandong and He'nan Province. In general, there is significant corresponding relationship between the spatial distribution of drought, poor harvest and famine, however, abnormally high probability of famine in south-central He'nan Province might be related to local special socio-economic vulnerability. This study would enhance our understanding of the nature of interactions between climate change and socioeconomic system. Further research would focus on the mechanism by which famine originated in the past, and the pathway through which climatic impacts were delivered in human society.     

Advances and Issues in Luminescence Dating of Loess Deposits in Arid Central Asia

High-resolution loess deposits are widely distributed in Arid Central Asia (ACA) and provide important records associated with dust transportation, paleoenvironmental and paleoclimatic evolution. The chronology is the foundation of the research into loess deposits as an environmental archive. In recent decades, the gradually developed optical dating method has been increasingly matured and become an important approach to establishing the loess-paleosol sequences. Here, we summarized and discussed previous work on loess chronology mainly based on optical dating approach in ACA. The following understandings have been listed: ① In comparison with optical dating method, the suitable material for ¹⁴C dating is uncommon in ACA. However, the dating range of luminescence dating is more extensive, and the dating materials are accessible. Thus, the optical dating is widely applicable in the establishment of loess framework in this area. ② Until now, the quartz Single Aliquot Regeneration (SAR) method can be applied to the establishment of loess-paleosol sequence since last glacial period. But several issues remain unaddressed. For example, the Optically Stimulated Luminescence (OSL) signal sensitivity of quartz grains are low in some areas. Furthermore, the results of OSL dating of different grain sizes within a single sample are inconsistent in some areas. The solution of these problems still requires more methodological research. ③ The post-IR IRSL (pIRIR) and multiple elevated temperature stimulation (MET-pIRIR) protoCols of feldspar have basically overcome the anomalous fading issue in the traditional IRSL dating process. In ACA, the framework since MIS 7 can be established with K-feldspar luminescence dating method. Compared with quartz luminescence characteristics, the K-feldspar luminescence signals are more sensitive and exhibit a high saturation level. In specific applications, it is necessary to establish the age frame according to the luminescence sensitivity, the age of samples or other factors.     

An Overview of Formation Mechanism and Disaster Characteristics of Post-seismic Debris Flows Triggered by Subsequent Rainstorms in Wenchuan Earthquake Extremely Stricken Areas

The Wenchuan earthquake induced large amounts of debris flows and catastrophic incidents triggered by subsequent rainstorms occurred frequently in the past 6 rainy seasons, and thus resulted in serious casualties, huge economic loss and long-term impact. In this paper, post-seismic debris flows distributed in 10 Wenchuan earthquake extremely stricken counties were verified and debris flow database consisting of 609 debris flows was established based on detailed investigation organized by Land and Resources Department of Sichuan Province. Combined with database and related studies, the impact of Wenchuan earthquake on debris flows was analyzed. And then variation of formation conditions including rainfall threshold and landform condition was analyzed by contrasting pre-seismic and post-seismic debris flows. Followed are some typical viewpoints on initiation mechanism of post-seismic debris flows. In the end of this paper, characteristics of postseismic debris flows triggered by subsequent rainstorms were comprehensively summarized, such as regional group occurrence, high frequency, high viscosity, chain effect, huge dynamics, large scale and long duration. We hope this paper will be helpful in understanding the formation mechanism, disaster characteristics and prevention countermeasures of post-seismic debris flows in Wenchuan earthquake extremely stricken areas.     

Simulation and Projection of Climate Change in Qinling and Surrounding Areas with NEX-BCC Model

Based on NEX-BCC_CGM1.1 global daily statistics downscaling climate data set, the latest release by American National Aeronautics and Space Administration (NASA), which has representative concentration path, by using linear fitting and empirical orthogonal function (EOF) analysis methods, the simulation capacity on precipitation and temperature in Qinling and its surrounding areas of this data sets was estimated and the possible changes of the precipitation, daily maximum and minimum temperature in the next stage under the two scenarios of Rcp4.5 and Rcp8.5 were analyzed. Results showed that: ①The inter-annual trend of average daily precipitation, maximum temperature, minimum temperature is simulated well by NEX-BCC_CGM1.1. The spatial distribution was in accordance with the observations. The deficiency is that the elements value and extreme frequency have systemic bias compared with the observations. ②Average daily precipitation will have increasing trend in the future in Qinling and its surrounding areas under the two scenarios of Rcp4.5 and Rcp8.5. For different level precipitation frequency, light rains will reduce and rainstorms will increase in the future. The spatial modes of precipitation in the future are shown as the variation of the uniform increase in the whole region (EOF1) and anti-phase change in northern and southern Qinling (EOF2). EOF1 will be positive phase in medium-term in the Mid-21^st century, where there will be significantly more means precipitation. ③Under the two scenarios, temperature warming trend is obvious, daily maximum temperature increasing trend is greater than minimum temperature, and the amplitude of temperature increase under Rcp8.5 is higher than Rcp4.5. The frequency of daily maximum temperatures greater than 36 ℃ will increase and low temperature less than -15 ℃ will reduce in the future, at the same time, high temperature (low temperature) increase (decrease) rate is more pronounced under Rcp8.5. Average daily maximum and minimum temperatures are shown uniform warming in the whole region (EOF1) and anti-phase change in northern and southern Qinling under two scenarios, but the spatial distribution has great difference.     

豫北焦作地区本溪组锂元素分布及富集特征

豫北焦作地区本溪组富铝含铁的黏土-铝土岩(矿)广泛分布,其中普遍伴生锂元素,为典型的沉积型锂矿床。为探讨锂元素分布和富集特征以及与主量元素的关系,对本溪组地层层序及沉积特征、岩(矿)石类型及组合进行了系统划分和Li与主量元素相关性分析。结果显示,焦作地区本溪组Li平均含量在平面分布上西部明显高于中、东部,富集程度具有"西高东低"特征;本溪组中各岩(矿)石Li含量差异较大,Li主要富集于本溪组中上部致密块状高铝黏土矿和硬质黏土矿中,部分软质黏土矿、铁质黏土岩和碳质黏土岩中Li有异常富集现象;富锂岩(矿)石Li与Al2O3、SiO2均先呈正相关,后呈负相关,且A/S值为0.8~1.5,Al2O3含量为30%~55%、SiO2含量为25%~45%时,Li最富集。综合分析认为,窑头、常平、盆窑北-张老湾南、焦谷堆-寨豁、栗井-大洼和上刘庄-王窑等矿区,可以连片大面积圈定锂矿体,是该区最佳锂资源潜力区。