河北坝上地区湖泊沉积物记录的中全新世干旱气候

根据位于典型草原带的河北坝上地区白诺尔及毗邻的内蒙古乌兰诺尔湖泊沉积物的K、Na、Ca、Mg等化学元素组成、总有机碳(TOC)与氧同位素(δ¹⁸O)的分析,以(K+Na+Ca+Mg)/(Fe+Mn)值指示干旱度,1δ8O值指示夏季风的强弱,TOC值指示湖区植被状况,探讨了该地区¹⁴C测年9.8~5.3 ka B.P.以来的气候变化与环境变迁。结果表明:两个剖面所记录的气候变化趋势相近,¹⁴C测年7.0~5.7 ka B.P.为偏干期。反映夏季风强弱的氧同位素指标与干旱程度的变化没有明显的对应关系,说明夏季风引起的降水量变化不是气候干湿变化的主要影响因子,温度升高导致的蒸发加强可能对气候干旱化的影响更加明显。     

极端干旱条件下柽柳种群蒸散量的日变化研究

利用波文比能量平衡法对额济纳绿洲柽柳种群蒸散进行测定。结果表明,在晴朗无云的条件下,蒸散速率日变化呈单峰型。蒸散从早晨630以后出现,上午蒸散率上升过程缓慢,到中午达到峰值,随后蒸散速率迅速下降,到1600蒸散速率降到最小,夜间无蒸散,常出现负值,呈大气凝结过程。净辐射对蒸散起决定作用,蒸散速率的变化趋势与净辐射变化基本一致,其日变化具有相同的峰型。柽柳种群蒸散量随风速的增加而增加。土壤温度对柽柳种群蒸散速率的影响不大,但土壤温度的增加值的变化与蒸散速率的变化基本一致。土壤含水量的变化对蒸散速率产生影响,土壤含水量降低,蒸散速率减弱,土壤含水量增加,蒸散速率加快。相关分析表明,环境因子对蒸散速率影响的贡献依次为土壤温度的升高值 > 净辐射 > 风速 > 土壤含水量 > 空气温湿度。     

黄土高原北部神府东胜矿区暴雨过程动态设计

应用水文学雨型动态设计原理,根据黄土高原北部神府东胜矿区暴雨特征,分析计算出该地区不同雨强不同重现期的暴雨量,并按照矿区最大1 h、6 h、12 h和24 h暴雨记录,采用不同历时曲线的主雨峰对齐、算术平均、滑动挑选的方法,分析概化出矿区不同时段每年一遇的暴雨历时控制雨型,绝大部分高强度暴雨均属于超前型。应用暴雨动态过程设计方法,可以计算分析无气象、水文测站的每一个小流域的暴雨过程。从而为流域产流汇流、侵蚀量的计算奠定了基础,并使所计算出的流量和侵蚀量更有可用性。     

基于陆面模式NCAR/CLM3.5的东北区域生长季地表干湿状况时空分布特征模拟研究

利用东北地区地面102站56 a(1951~2006年)逐日气象观测资料,驱动NCAR陆面模式CLM 3.5,模拟东北地区生长季地表水分盈余量(Surface Water Surplus,SWS),探讨和分析了东北地区生长季1951~2006年地表干湿状况的时空变化规律。结果表明:1971~2000年平均东北地区生长季SWS反映的地表干湿状况具有较大的地域差异,全区SWS为100~800 mm;中、西部为SWS低值区,属半干旱、半湿润区;东、南、北部为相对高值区,属湿润、半湿润区。生长季地表干湿状况存在显著的年际、年代际变化;56 a来,东北地区生长季SWS呈线性减少趋势,即地表变干,SWS空间分布的年代际变化,同样表现为变干趋势,尤其2000~2006年是地表变干最为显著的时期,表明在全球变暖背景下东北地区地表干旱化趋势增强。分析表明地表干湿状况是下垫面与气候变化共同作用的结果,研究地表干湿状况需要综合考虑水分收支项。     

Environmental Geochemistry and Acid Mine Drainage Evaluation of an Abandoned Coal Waste Pile at the Alborz-Sharghi Coal Washing Plant,NE Iran

In this paper, an abandoned waste coal pile, which is resulted from Alborz-Sharghi coal washing plant, NE of Iran was mineralogically and geochemically characterized to evaluate pyrite oxidation, acid mine drainage (AMD) generation, and trace element mobility. After digging ten trenches and vertical sampling, a quantitative method including the atomic absorption test, and the quality-based methods including optical study were carried out for determination of pyrite fractions in the waste pile. The geochemical results revealed that the fraction of remaining pyrite increased with depth, indicating that pyrite oxidation is limited to the shallower depths of the pile which were confirmed by variations of sulfate, pH, EC, and carbonate with depth of the pile. To evaluate the trend of trace elements and mineralogical constituents of the waste particles, the samples were analyzed by using XRD, ICP-MS, and ICP-OES methods. The results showed the secondary and neutralizing minerals comprising gypsum have been formed below the oxidation zone. Besides, positive values of net neutralization potential indicated that AMD generation has not taken in the waste pile. In addition, variations of trace elements with depth reveal that Pb and Zn exhibited increasing trends from pile surface toward the bottom sampling trenches while another of them such as Cu and Ni had decreasing trends with increasing depth of the waste pile.     

青海大柴旦地区低品位硼矿富集加工技术创新效果分析

青海省大柴旦地区是我国硼资源主要产地之一,经数十年的开采,矿体中富矿已基本枯竭。通过对大柴旦地区硼资源的分析,重点介绍了分级富集与沉矿浮选联合流程法和直接分级法两种低品位硼矿富集技术,同时对两种技术的内容、路线以及创新效果进行了讨论,并由创新效果的比较分析,得出两种方法的优点和创新性,同时提出对未来低品位硼矿富集技术的展望。     

Dry/wet variation recorded by shrub tree-rings in the central Badain Jaran Desert of northwestern China

The dendrochronological study of shrubs is a new field, particularly with respect to desert areas. Using a dendrochronological perspective, we studied the radial growth and the climatic response model of the common beancaper (Zygophyllum xanthoxylum Maxim) in three sampling sites in the Badain Jaran Desert of northwestern China. The results showed that the radial growth of the common beancaper was primarily affected by precipitation during the pre-growing and growing seasons, especially during July. Variation in wet/drought periods over the last 160 years in the study area was analyzed using a radial growth climatic response model and data on regional chronology. Using decadal time scales, three wet periods were identified in the Badain Jaran Desert: the 1840s to early 1850s, the early 1890s to the 1900s and the late 1970s to the mid-1980s. Similarly, transitions from dry to wet periods over the last 160 years occurred in the late 1850s, mid-1870s, early 1880s, early 1900s, mid-1920s, early 1950s, early and late 1970s and early 1990s. These results are helpful for understanding regional climate change and the desertification process in arid desert regions.     

渭北旱塬土壤水分空间变异性

渭北旱塬是陕西省重要的苹果生产基地，探讨该区不同土地利用的土壤水分时空变异特征，对农业生产布局、种植业结构调整和减少径流、控制侵蚀具有特殊的现实意义。本文用地统计学的理论和方法，分析了渭北旱塬区3种主要土地利用类型农地、苹果地和苜蓿地3个土层深度(0～20cm、60～80cm、280～300cm)的土壤水分空间变化趋势。变异函数分析结果表明，3种土地利用类型的土壤水分具有明显的空间变异特性。在0～20cm土层，空间变异性尺度为9～16m，60-80cm土层为5～12m，280-300cm土层深为5～10m，空间变异性程度随尺度变化。自相关尺度为1～17m，自相关部分的空间变异性在0～20cm、60～80cm和280-300cm分别占总空间变异性的90．0％～94．0％、84．0％～98．0％和85．0％～94．0％，明显大于随机部分的空间变异性。从苜蓿地、苹果地到农地，空间自相关的尺度逐渐增大。各向异性分析表明，农地和苜蓿地在表层(0～20cm)具有明显的各向异性，而苹果地的土壤水分含量接近各向同性。     

Simulations of an isotopic fractionation by freezing in an open system

This paper presents a model of isotopic fractionation by freezing under near equilibrium conditions in an open system and uses the model to predict the fractionation curve and slope gradient of δ 18 O versus δD. The simulation results show that 1) the fractionation curve and slope gradient are determined by the ratio of freezing rate to input rate, 2) the isotopic value in the initial stage of freezing is determined by the isotopic value of initial water; 3) in the latter half of freezing in an open system, the isotopic value converges to a certain value determined by that of input water. These results suggest that the shape of the fractionation curve is the method to distinguish whether freezing occurred in a closed or open system. This analysis is applied to an isotopic curve observed in basal ice of Hamna Glacier, Sya drainage, East Antarctica. The isotopic curve indicates formation by regelation in an open system with a ratio of freezing/input rates of about 10/4.     

云南中部区域气温变化特征及其受城市化影响程度分析

利用云南中部区域1961—2010年逐月气温资料,采用趋势系数、气候倾向率、Mann-Kendall突变检验、Morlet小波等方法分析该地区气温的时空变化特征,并采用城郊对比法分析城市化对于气温变化的影响程度。结果表明:(1)该地区年均气温上升趋势明显,年均气温存在着24 a的主周期,并于1997年发生了突变,之后进入了一个显著增暖时期。四季平均气温均呈上升趋势,其中冬季气温增幅最大。(2)除西北部的元谋干热河谷存在降温趋势外,其余地区均呈现增温趋势,升温中心位于城市,其中以昆明的升温趋势最为显著。(3)城市化对气温序列变化趋势的影响显著,城市化引起的增温速率在冬季最大,而城市化对气温变化趋势贡献最高的季节则为春季。(4)昆明的城市化增温速率最大,楚雄次之,玉溪最弱;三市的热岛强度从1985年开始逐年增强,2000年后达到最高值,之后趋于平缓;冬春季节的城市化增温速率要明显高于夏秋季节,城市化增温贡献最高的季节为春季。     

南疆盆地翻山型沙尘暴环流动力结构分析

2003年4月8日至9日发生了一次超极地冷空气入侵新疆并翻越天山造成南疆盆地大范围强沙尘暴过程,分析沙尘暴强盛期的高度场、高空急流异变、螺旋度场、散度场和不稳定发展,揭示了该类沙尘暴强盛期的环流动力结构。结果表明:①伊朗高压的爆发性发展与乌拉尔山脊叠加形成长波脊,导致泰米尔半岛的极地强冷空气南下,并直插新疆越过天山到达塔里木盆地,造成大范围沙尘暴天气;②强沙尘暴天气产生的根本原因是西西伯利亚地面冷高压爆发性南下并强烈发展;③高空西风急流发生异变在南疆盆地上空形成急流区,并通过动量下传导致地面大风,是大范围沙尘暴发生的动力条件;④沙尘暴区上空螺旋度垂直分布低层为正值、高层为负值,揭示强的旋转上升运动是大范围沙尘暴发生的动力条件。⑤低层辐合高层辐散的垂直结构,易于发生近地面大风和上升气流;⑥该次沙尘暴是一次大范围强对流天气,大气层结处于对流中性或对流不稳定状态,但都有强的斜压不稳定发展,并冷暖空气交换剧烈。沙尘暴影响前塔里木盆地有一个能量明显聚集期,但聚集时间很短。     

瞬变电磁法解释煤矿地下含水构造研究——以内蒙古东明露天矿为例

内蒙古呼伦贝尔东明露天煤矿矿坑边帮地下水渗漏的问题日益严重,矿区原有的疏干降水井排水能力及效果已不能满足生产需求,同时对矿区生态环境也造成一定程度破坏。目前,对矿区周边的水文地质条件和水力联系缺乏精准全面的认识和数据。通过瞬变电磁法对矿区地下水渗漏较严重的西北部进行三条勘探线(77个物理点)勘查,结果表明该区存在三处视电阻率低阻异常带,判定其主要为含水断层(裂隙)所致;结合矿区地形、地层岩性与矿区地下水矿化度,对上述异常带进行了科学合理的综合解释,并结合新施工的疏干降水井抽水验证了上述异常的可靠性,为矿区后期布置疏干降水井圈定了靶区,对当地同类型矿区地下水渗漏灾害治理起到了应用示范作用。     

Estimation of Coal Reserves for UCG in the Upper Silesian Coal Basin,Poland

One of the prospective methods of coal utilization, especially in case of coal resources which are not mineable by means of conventional methods, is underground coal gasification (UCG). This technology allows recovery of coal energy “in situ” and thus avoid the health and safety risks related to people which are inseparable from traditional coal extraction techniques. In Poland most mining areas are characterized by numerous coal beds where extraction was ceased on account of technical and economic reasons or safety issues. This article presents estimates of Polish hard coal resources, broken down into individual mines, that can constitute the basis of raw materials for the gasification process. Five mines, representing more than 4 thousand tons, appear to be UCG candidates.     

河南省城市空气质量特征与污染防治对策

根据《河南省主要城市空气质量日报》公布的数据资料,对河南省15个主要城市的空气质量进行了统计分析,总结出其主要城市的空气污染特征及其成因,提出了空气污染防治对策。     

陕西咸阳人工林地土壤干层研究

根据咸阳庞西村苹果林地、梧桐林地和草地土壤含水量测定,研究了0~6m土壤含水量的变化和土壤干层特点与分布。结果显示, 咸阳人工林地从表层向下含水量呈现由高到低再到低的变化;10龄苹果林地2~4m深处土壤含水量平均为8.3%,12龄梧桐林2~4m深处土壤含水量平均为8.6%,均发育了明显的土壤干层;4龄苹果林下土层有干化显示,但无干层发育;草地土层含水量明显较苹果林地高,无土壤干化的显示。研究表明,土壤干层形成的具体原因一是降水量少决定的薄膜水带埋藏深度小,二是薄膜水的运移速度缓慢和含水量低。为保持人工林基本正常的生长和土壤水的正常运移,应避免严重的土壤干层出现。咸阳附近土壤干层的出现表明土壤干层在黄土高原广泛分布,该区的植被恢复首先应以疏林或森林草原为主,待土壤水分改善后再考虑恢复森林植被。     

Generation of Long Internal Gravity Waves in Waveguides by Rising Buoyant Air Masses and Other Sources

Summary The displacement fields generated in an internal gravity wave waveguide between plane rigid walls are compared for two types of source: an explosive point source and a rising buoyant sphere moving at constant speed. It is concluded that for large enough spheres and comparable energy expenditures, the buoyant sphere is a far more efficient source of long internal gravity waves. In particular it appears possible to conclude that, in the case of large events such as nuclear or volcanic explosions in the atmosphere, the rising heated air mass can generate long wavelength (Λ > 500 km) internal gravity waves at ionospheric heights.     

Application of Tree-Based Predictive Models to Forecast Air Overpressure Induced by Mine Blasting

Natural Resources Research - In surface mines and underground excavations, every blasting operation can have some destructive environmental impacts, among which air overpressure (AOp) is of major...