同忻井田煌斑岩侵入特征及对煤层和煤质的影响

介绍了同忻井田煌斑岩的岩性及产状、时代,分析了岩浆上升通道,研究了煌斑岩侵入特征及其对煤层、煤质的影响。      

干旱区土壤小麦根系界面Pb、Ni行为的环境影响——以甘肃省白银市区污灌耕作土为例

对大田环境土壤小麦根系体系Pb、Ni行为环境影响的调查研究表明:同种元素的影响程度最大,共存元素对Pb、Ni行为的影响多表现为协同效应;Pb、Ni由土壤向根系迁移的趋势较弱;pH值、粘粒及粗粉砂粒含量与根系Pb含量呈负相关,P和砂粒含量与根系Pb含量呈正相关,其它分析因子值与根系Pb含量不相关;粗粉砂粒组成与根系Ni含量呈负相关,砂粒组成与根系Ni含量呈正相关,其它分析因子值与根系Ni含量不相关。多元逐步回归分析表明:Pb是影响根系同种元素吸收的主要因子,而Ni不是。     

中国东北地区地表水资源与气候变化关系的研究

利用NCEP/NCAR 1948~2000年共53年的月平均再分析资料,统计分析了东北地区不同区域和季节气温和(或)降水变化对蒸发量、地表径流量以及浅层和深层土壤含水量的影响。结果表明,东北地区地表水资源各分量与气温和降水之间有着较好的相关关系。还建立了气温和(或)降水变化对水资源各分量影响的简单统计评估模型,利用这些模型研究了东北地区地表水资源各分量对气温和(或)降水变化的响应情况,得出东北地区较小的"气候扰动"可能会导致径流量等地表水资源较大的变化和其它一些有意义的结果。     

水盐动态与土地利用变化相互作用的分析

利用1987年和1998年两期土地利用现状图,1988~1998年水文资料和2000年、2001年地下水和土壤水、盐含量的监测资料,分析三工河流域水盐的时空动态变化对流域土地利用的影响。1988~1998年三条河流年出山口总径流量10年间无显著变化,但上游老绿洲耕地面积逐步扩大,引水量逐年增加,可以占到出山口径流总量的90%以上。1998年相对于1988年,上游绿洲地下水位有所下降,而所有下游观测点的地下水位均有所升高,盐渍化问题加剧。通过2000年和2001年三工河流域下游的新垦绿洲地下水、土壤的连续观测表明,从绿洲、过渡带到沙漠中,土壤盐分含量的变化梯度不大,差异不显著,而水分则有显著的下降趋势。但是在过渡带由于受绿洲灌溉过程的影响,地下水位较浅,土壤含水量较高,植被较为稳定,因此绿洲边界始终没有变化。因此水分的减少是绿洲过渡带动态稳定的关键限制因子。绿洲内的撂荒地和靠近绿洲的荒漠草地受绿洲内部灌溉过程的影响,地下水位升高,超过了地下水的临界深度,同时又因为缺少灌溉的反复淋洗,在强烈的蒸发作用下,盐分的表聚现象十分明显,而且整个剖面内盐分的含量都较高,土壤的盐渍化现象非常严重。     

慕士塔格卡尔塔马克冰川水文观测与特征分析

基于2003年卡尔塔马克冰川强烈消融期连续的气象与水文观测, 对卡尔塔马克冰川消融的影响因素和融水径流特征进行了分析. 结果表明: 消融期的冰川融水流量与气温之间存在着良好的相关关系, 降水过程会导致气温降低抑制冰川消融. 卡尔塔马克冰川纯冰川融水径流模数为62.4 L·s^-1·km^-2, 冰川区融水径流深为 463.5 mm. 根据现场降水损失试验, 总损失达 26%, 校正后大本营处2003年降水量为134 mm.     

极端干旱区胡杨水势及影响因子研究

依据2002年4月至2003年9月在极端干旱区额济纳旗的观测资料,对胡杨叶水势的日、季变化规律及影响因子进行了分析研究。试验结果表明:胡杨叶水势日变化均值为(-2.86±0.75)MPa,季变化均值为(-2.72±0.14)MPa。叶水势日、季节变化曲线呈单峰型,这种变化规律是胡杨适应该地区生境的生理特性之一。对胡杨不同部位和不同叶型的叶水势测定结果表明,上部的叶水势比下部低,披针叶的叶水势比阔卵叶的叶水势高,这与水分移动的规律相符合。胡杨叶水势的日、季变化与气温、大气相对湿度、辐射照度间有十分显著的相关关系。与土壤水分间也有十分显著的相关关系,土壤含水量下降,蒸腾加快,叶水势降低,土壤含水量增加,蒸腾减弱,叶水势回升。     

A double-halocline structure in the Canada Basin of the Arctic Ocean

1IntroductionAs a particular hydrographic feature,the upperArctic Ocean is salinity-stratified.A year-round halo-cline exists between the fresher,colder mixed Layerand the saltier,warmer middle layer(the Atlantic Lay-er),which is important to the permanent sea ice coverin the Arctic Ocean for it insulates the ice pack fromthe heat in the Atlantic Layer throughout the Arctic O-cean(Maykut and Untersteiner,1971).Characterizedby its vertically uniform temperature near freezingpoint,the haloc…     

Potential evapotranspiration and its attribution over the past 50 years in the arid region of Northwest China

Evaporation paradox and its attribution have become a hot research topic in hydrology in recent years. This study estimates the potential evapotranspiration (ET₀) using modified Penman–Monteith method and analyzes the corresponding trend attribution based on the long‐term meteorological data collected at 81 ground‐based meteorological stations in Northwestern arid region of China during the period 1958–2010. The analysis results show: (1) The ET₀ has exhibited an obvious decreasing trend until the early 1990s; however, the downward trend has been reversed to an upward trend after then. (2) Decrease in diurnal temperature range (DTR) and wind speed (WS) may lead to the decrease of ET₀ during 1956–1993. The change of dominant factors in the ET₀ trend has differences after the early 1990s; observed increase in WS is the primary factor contributing to the reversion of ET₀. Copyright © 2012 John Wiley & Sons, Ltd.     

基于VB+MO的一种在飞机增雨效果统计评估中不规则影响区计算的适用方法

文章建立了基于VB＋MO地理信息系统二次开发技术,结合二维线源扩散方程,更加客观地计算出飞机播云不规则影响区的范围、面积与体积降水量的适用方法,并结合CA-FCM方法,实现了该技术方法在飞机增雨效果统计评估系统中自动化应用。结合吉林省飞机增雨作业实例介绍了该方法的具体应用,并且对结果进行了讨论。     

Climate Comparisons and Change Projections for the Northwest Atlantic from Six CMIP5 Models

Abstract

Key physical variables for the Northwest Atlantic (NWA) are examined in the “historical” and two future Representative Concentration Pathway (RCP) simulations of six Earth System Models (ESMs) available through Phase 5 of the Climate Model Intercomparison Project (CMIP5). The variables are air temperature, sea-ice concentration, surface and subsurface ocean temperature and salinity, and ocean mixed-layer depth. Comparison of the historical simulations with observations indicates that the models provide a good qualitative and approximate quantitative representation of many of the large-scale climatological features in the NWA (e.g., annual cycles and spatial patterns). However, the models represent the detailed structure of some important NWA ocean and ice features poorly, such that caution is needed in the use of their projected future changes. Monthly “climate change” fields between the bidecades 1986–2005 and 2046–2065 are described, using ensemble statistics of the changes across the six ESMs. The results point to warmer air temperatures everywhere, warmer surface ocean temperatures in most areas, reduced sea-ice extent and, in most areas, reduced surface salinities and mixed-layer depths. However, the magnitudes of the inter-model differences in the projected changes are comparable to those of the ensemble-mean changes in many cases, such that robust quantitative projections are generally not possible for the NWA.