天山山区近50年面雨量分布及变化特征

天山山区范围大,地形复杂,但测站稀少,而且分布很不均匀。为了尽可能的反映天山山区气候要素分布特征,利用1961~2009年天山山区44个气象站和10个水文站的观测资料,结合数字高程模型（DEM）1km?km网格数据,采用了自然正交分解（EOF）、多元回归分析、最大熵谱值分析等方法,对天山山区面雨量进行了计算,建立了区域面雨量时间序列,研究其时空分布特征及变化规律。天山山区的降水基本上呈现北多南少,西多东少的特征,年平均面雨量1093.2?08m3,1987年发生突变。冬季降水在年际变化和年代际变化特征上都呈现出明显的增加趋势。     

南岭山地高速公路雾区能见度预报系统

在研究南岭山地浓雾的气候规律，开展了2次多学科综合野外观测，对典型个例进行了天气学分析、雾的宏观结构特征分析、雾的微物理特征分析，在利用数值试验分析了雾生成的物理机制等研究的基础上，研制开发了4种南岭山地京珠高速公路云岩雾区的能见度预报方法，包括：中尺度数值模式产品释用方法、结构预测方法、天气学指标预报方法和动态统计预报方法；并研制了相应的自动化程度高的预测预报系统，与京珠高速公路粤境北段通车同步投入准业务运行，使用雾区路段的5套自动气象站和能见度仪资料，制作的集成预报结果为高速公路行车安全提供服务，经过各种方法的独立预报检验和准业务运行服务的预报结果检验，预报准确率比较高，提供服务的集成预报准确率可达83．3％。     

Till fabric and grain-size analysis of glacial sequences in the Upper Sil River Basin,Cantabrian Mountains,NW Spain

Fabric and grain-size analysis of eight deposits present in the Upper Sil River Basin palaeoglacial system of northwest Spain were used to interpret till types and to reconstruct the glacial paleoprocess history of this region. They are represented by lodgement, deformation, and melt-out tills. The first, representative of glacial advance stages, present cluster fabrics and are generally composed of poorly sorted and finer sediments. Melt-out and deformation tills, representative of stages of glacial stability followed by fast recession, present transitional to girdle fabrics and are composed of poorly sorted coarser sediments. In any case, multiple criteria, including lithological, clast-shape, or structural data, support these directional and grain-size observations. These sequences, most of them located in the snout area of the Sil palaeoglacier, are important in the reconstruction of glacial dynamics due to poor preservation of landforms related to the maximum glacial advance. This palaeoglacial system was formed by multiple tributaries and had an extension of over 450 km², with the Sil paleoglacier being 51 km long during its maximum glacial advance.     

平衡剖面技术在龙门山中段构造解释中的应用

龙门山推覆冲断带地形条件恶劣,构造断裂复杂,阻碍了该区油气资源的勘探进程。为搞清龙门山推覆冲断带下的构造样式,验证其构造解释方案,应用平衡剖面技术,对龙门山中段具典型构造特征的地质、地震综合解释剖面进行平衡恢复。实例分析证明,平衡剖面技术可正确指导龙门山中段构造剧烈变形区的构造解释方案,并可定性、定量分析构造变形期次和变形程度,为下一步油气勘探提供可靠依据。      

Environmental change and water management in the Pyrenees: Facts and future perspectives for Mediterranean mountains

This paper analyses the effect of environmental changes observed in the 20th century on hydrology and water management in the southern Pyrenees, in terms of land use and climate. Moreover, a projected water-resource scenario for the 21st century is presented and discussed. Our results demonstrate that changes in precipitation, temperature, and snow accumulation, together with an increase in vegetation density in headwater regions, have led to a marked reduction in water availability in the region. Water resource managers have introduced major changes to dam operations to meet increasing water demand for irrigation purposes in lowland areas. Climatic and land-cover scenarios for the next century indicate that the sustainability of the equilibrium between available resources and water demand will be seriously threatened. These changes predicted for the Pyrenees may be representative of the changes that will occur within many other Mediterranean mountain sectors with similar climatic and socio-economic conditions.     

On the morphological characteristics of overdeepenings in high‐mountain glacier beds

Overdeepenings, i.e. closed topographic depressions with adverse slopes in the direction of flow, are characteristic for glacier beds and glacially sculpted landscapes. Quantitative information about their morphological characteristics, however, has so far hardly been available. The present study provides such information by combining the analysis of (a) numerous bed overdeepenings below still existing glaciers of the Swiss Alps and the Himalaya‐Karakoram region modelled with a robust shear stress approximation and (b) detailed bathymetries from recently exposed lakes in the Peruvian Andes. The investigated overdeepenings exist where glacier surface slopes are low (< 5°–10°), occur in bedrock or morainic material and are most commonly a fraction of a kilometre squared in surface area, hundreds of metres long, about half the length in width and tens of metres deep. They form under conditions of low to high basal shear stresses, at cirque, confluence, trunk valley and terminus positions. The most striking phenomenon, however, is the high variability of their geometries: Depths, surface areas, lengths and widths of the overdeepenings vary over orders of magnitude and are only weakly – if at all – interrelated. Inclinations of adverse slopes do not differ significantly from those of forward slopes and are in many cases higher than so far assumed theoretical limits for supercooling of ascending water and corresponding closure of sub‐glacial channels. Such steep adverse slopes are a robust observation and in support of recently developed new concepts concerning the question about where supercooling of sub‐glacial water and closure of ice channels can or must occur. However, the question of when and under what climatic, topographic and ice conditions the overdeepenings had formed remains unanswered. This open question constitutes a key problem concerning the interpretation of observed overdeepenings, the understanding of the involved glacio‐hydraulic processes and the possibility of realistic predictive modelling of overdeepening formation. Copyright © 2016 John Wiley & Sons, Ltd.     

祁连-龙首山元古宙大火成岩省与金川型铜镍矿关系探讨

祁连-龙首山地区发育多处镁铁-超镁铁质岩体,其成矿表现及与金川矿床所代表的大规模岩浆事件的关系尚不清晰。本次研究通过区域地质建造对比、详细剖面刻画,岩石学、地球化学辅助,厘定了祁连-龙首山地区镁铁-超镁铁质岩体年代学格架与含矿性评价,初步表明金川超大型岩浆铜镍硫化物矿床是新元古代大规模岩浆事件的产物,可能与诺迪尼亚超大陆的裂解所导致的大火成岩省有关。在其外围,发育有多期镁铁-超镁铁质岩体,尽管南祁连化隆地区所发现的镁铁-超镁铁质岩体与金川铜镍矿为非同期的产物,但也表明是一期比较重要的岩浆铜镍矿成矿事件,对于拓展区域找矿实现找矿突破具有重要作用。     

Structure and geochronology of the Tongbai complex and their implications for the evolution of the Tongbai orogenic belt,central China

The Tongbai orogenic belt has an overall antiformal geometry and the hinge of the antiform is sub-horizontal and trends NW–SE. The Tongbai complex (TBC) in the core of the antiform is bounded by the S-dipping Yindian–Malong shear zone in the south, the sub-horizontal Taibaiding shear zone at the top and the N-dipping Hongyihe–Tongbai shear zone in the north. The three shear zones have dextral, top-to-NW and sinistral movement, respectively. They are parts of a single shear zone, termed the Tongbai shear zone, that has a uniform top-to-NW sense of shear. Three samples of deformed granitoid (mylonite or protomylonite) from the shear zone have U–Pb zircon ages of 145 ± 6 Ma, 142 ± 2 Ma and 131 ± 6 Ma, respectively. An L-tectonite in the TBC yielded a metamorphic age of 137 ± 8 Ma and a migmatite an age of 137 ± 1 Ma. The Tongbai shear zone is intruded by undeformed Early Cretaceous granite and dykes and deformation in the shear zone is constrained to ca. 140–135 Ma, synchronous with metamorphism and migmatization in the TBC. Early Cretaceous magma emplacement and the associated uplift modified the TBC into a gentle antiform and the uplift may have continued to ca. 102–85 Ma. Similar geometry and kinematics have been documented in the Dabie orogenic belt to the east, which suggests that the Central Orogenic Belt in China probably experienced a uniform orogen-parallel extension and top-to-NW shearing in the ductile lithosphere in the Early Cretaceous.     

基于遥感影像的雪线高程提取方法对比分析——以天山北坡为例

利用2010-2014年6~8月MOD10A1、MOD10A2及HJ-1/CCD数据,以天山北坡为研究区,对比分析了积雪持续时间比率法及最大值合成法在雪线高程提取中的精度和适用性。结果表明:当MOD10A1以旬合成,积雪持续时间比率阈值为40%时,提取的雪线高程与"真值"最为接近;基于混淆矩阵法,以目视解译得到的HJ-1/CCD积雪面积为"真值",分析得出,积雪持续时间比率法提取积雪面积的总体精度较高,为98.59%,khat系数为0.90,最大值合成法的总体精度仅为85.29%,khat系数为0.70;基于统计学的方法,计算得出,积雪持续时间比率法提取的雪线高程与"真值"的相关系数较高,为0.77,其平均误差、正、负误差、绝对平均误差以及均方根误差相对较低;最大值合成法提取的雪线高程与"真值"的相关系数较低,仅为0.54,其平均误差、正、负误差、绝对平均误差以及均方根误差相对较高;积雪持续时间比率法提取的雪线高程结果优于最大值合成法。     

湖南省山区范围划分初探

山地和山区范围的界定是山区数据库建设和数字山地战略实施的基础。该文在GIS空间分析和数理统计分析技术的支持下,选取高程、道路密度、林草地比例、耕地比例、人口密度和GDP 6个因子,通过构建基于栅格单元的边缘生长模型,计算非山地的栅格单元被划分为山区的概率,并设定一个阈值以区分山区和非山区,在湖南省山地范围的基础上探讨其山区范围的划分。计算得到湖南省山区面积占总面积的64.52%,相对于山地面积增长了43.47%,且将原本孤立的山地连接成片,山区更具连续性和完整性。