Growing season evapotranspiration in boreal fens in the Athabasca Oil Sands Region: Variability and environmental controls     

Olena Volik  Eric Kessel  Adam Green  Richard Petrone  Jonathan Price 《水文研究》2021,35(2):e14020

Current efforts to assess changes to the wetland hydrology caused by growing anthropogenic pressures in the Athabasca Oil Sands Region (AOSR) require well-founded spatial and temporal estimates of actual evapotranspiration (ET), which is the dominant component of the water budget in this region. This study assessed growing season (May–September) and peak growing season (July) ET variability at a treed moderate-rich fen and treed poor fen (in 2013–2018), open poor fen (in 2011–2014), and saline fen (in 2015–2018) using eddy covariance technique and a set of complementary environmental data. Seasonal fluctuations in ET were positively related to net radiation, air temperature and vapour pressure deficit and followed trends typical for the Boreal Plains (BP) and AOSR with highest rates in June–July. However, no strong effect of water table position on ET was found. Strong surface control on ET is evident from lower ET values than potential evapotranspiration (PET); the lowest ET/PET was observed at saline fen, followed by open fen, moderately treed fen, and heavily treed fen, suggesting a strong influence of vegetation on water loss. In most years PET exceeded precipitation (P), and positive relations between P/PET and ET were observed with the highest July ET rates occurring under P/PET ~1. However, during months with P/PET > 1, increased P/PET was associated with decreased July ET. With respect to 30-year mean values of air temperature and P in the area, both dry and wet, cool and warm growing seasons (GS) were observed. No clear trends between ET values and GS wetness/coldness were found, but all wet GS were characterized by peak growing seasons with high daily ET variability.  相似文献   

First Multi‐Isotopic (Pb‐Nd‐Sr‐Zn‐Cu‐Fe) Characterisation of Dust Reference Materials (ATD and BCR‐723): A Multi‐Column Chromatographic Method Optimised to Trace Mineral and Anthropogenic Dust Sources     

Aubry Vanderstraeten  Steeve Bonneville  Stefania Gili  Jeroen de Jong  Wendy Debouge  Philippe Claeys  Nadine Mattielli 《Geostandards and Geoanalytical Research》2020,44(2):307-329

Atmospheric dust is an integral component of the Earth system with major implications for the climate, biosphere and public health. In this context, identifying and quantifying the provenance and the processes generating the various types of dust found in the atmosphere is paramount. Isotopic signatures of Pb, Nd, Sr, Zn, Cu and Fe are commonly used as sensitive geochemical tracers. However, their combined use is limited by the lack of (a) a dedicated chromatographic protocol to separate the six elements of interest for low‐mass samples and (b) specific reference materials for dust. Indeed, our work shows that USGS rock reference materials BHVO‐2, AGV‐2 and G‐2 are not applicable as substitute reference materials for dust. We characterised the isotopic signatures of these six elements in dust reference materials ATD and BCR‐723, representatives of natural and urban environments, respectively. To achieve this, we developed a specific procedure for dust, applicable in the 4–25 mg mass range, to separate the six elements using a multi‐column ion‐exchange chromatographic method and MC‐ICP‐MS measurements.  相似文献   

地缘政治视角下中亚“颜色革命”易发程度分析     

李希雅  王礼茂 《世界地理研究》2019,28(6):42-49

基于地缘政治视角，分析本世纪初发生在原苏联地区“颜色革命”的诱发因素，认为美国根据其地缘战略格局对“颜色革命”发生地存在一定程度的主观选择性，国家内部经济、政治、社会等层面的矛盾也同样作为发生背景。在中亚地缘格局动态分析的基础上，结合中亚五国形势，从时间和空间双重维度对中亚地区未来发生“颜色革命”的可能性进行识别与评判，得出1) 整体来看，中亚近期内爆发“颜色革命”可能性较小，但从长远来看不能掉以轻心。2)土、乌未来稳定可期，塔、吉、哈需谨防“颜色革命”卷土重来。  相似文献   

利用InSAR资料反演宁洱Ms6.4地震震源参数及库仑应力变化     

陈晨月  冯光财  高华  杨怀宁 《大地测量与地球动力学》2019,39(3):295-301

首先利用ALOS PALSAR数据，通过D-InSAR技术获取2007-06-03云南宁洱MS6.4地震的同震形变场，然后基于Okada弹性半空间位错模型反演该地震的断层几何以及精细滑动分布，最后计算宁洱地震后周边断层的静态库仑应力变化。结果表明，形变主要集中在西盘，最大视线向形变量为51.6 cm；反演得到的震源位置为23.05°N、101.02°E，深度3 km，断层走向145°，倾向49.5°，平均滑动角153°，发震断层为NNW向普洱断裂，断层活动以右旋走滑为主，兼具逆冲分量；断层面最大滑动量为1.2 m，反演得到的震级为MW619。基于库仑应力场发现，磨黑断裂处于库仑应力增加区域，而2014年景谷地震位于负值区域。结合实地考察资料和反演结果表明，宁洱地震为浅源地震，但断层并未出露地表。  相似文献   

基于GPS和水准数据的微粒群算法联合反演祁连山北缘断裂三维滑动速率     

刘杰 《大地测量与地球动力学》2019,39(9):906-909

将微粒群算法与位错理论模型相结合，采用中国地壳运动观测网络提供的青藏高原地区2001~2004年GPS测量数据和2000~2006年水准测量数据，通过常规定权和附有相对权比的方法对祁连山北缘断裂的三维滑动速率进行联合反演，并与蚁群算法反演结果进行对比。结果表明，微粒群算法收敛速度快、稳定性高，结合经典位错理论模型，是一种可以有效求解断层三维滑动速率反演问题的优化算法，在大地测量反演领域极具应用潜力。  相似文献   

Studying Resource-Dependent Communities Through a Social-Ecological Lens? Examining Complementarity with Existing Research Traditions in Canada     

Sara Teitelbaum  Annie Montpetit  Jean-François Bissonnette  Clément Chion  Guy Chiasson  Frédérik Doyon 《社会与自然资源》2019,32(1):93-112

This article explores the suitability of Ostrom and colleagues' social-ecological systems framework (SESF) for the study of resource-dependent communities in Canada. Through a broad literature about resource-dependent communities in Canada, three main approaches are identified, named staples research, rural development, and sustainability studies. Each of these research traditions is analyzed with regards to a common set of criteria – focus, scale, methods, treatment of institutions, and treatment of environmental dimensions. Research in each category is compared and contrasted with the SESF approach, to identify areas of overlap and divergence. Results indicate that the SESF is unlikely to provide additional benefit in terms of in-depth of social analysis, however, it does provide a unique contribution in terms of its coupled approach to conceiving social and ecological systems and its ability to operationalize these relationships through structured variables.  相似文献   

BDS卫星差分码偏差稳定性分析及其短期预报     

梅登奎  闻德保 《大地测量与地球动力学》2020,40(7):746-750

利用MGEX(multi-GNSS experiment)发布的BDS卫星差分码偏差(differential code bias, DCB)产品，比较分析不同太阳活动水平下BDS卫星DCB产品的稳定性变化特性，并采用差分自回归移动平均(auto-regressive integrated moving average, ARIMA)时间序列预测模型，实现不同太阳活动水平下BDS卫星DCB的短期预报。结果表明，在太阳活动高年，BDS卫星DCB日解值稳定度、月稳定性均明显低于太阳活动低年，且不同卫星星座类型的BDS卫星DCB稳定性也存在差异；ARIMA时间序列预报结果与MGEX发布值符合程度较好，优于多项式拟合法预测结果。  相似文献   

江南造山带(湖南段)金矿成矿规律与资源潜力   总被引：1，自引：0，他引：1  

黄建中  孙骥  周超  陆文  肖荣  郭爱民  黄革非  谭仕敏  隗含涛 《地球学报》2020,41(2):230-252

扬子地块—华夏地块经历武陵期—雪峰期增生造山-碰撞造山形成江南造山带,构成统一的华南板块,进入板内演化阶段。本文从构造-岩浆作用-沉积建造角度,结合地质年代学、古地磁、岩相古地理分析,加里东运动、印支运动属陆内作用,造就了加里东期、印支期两次主要的金矿成矿事件。湖南雪峰山—幕阜山(俗称“金腰带”)加里东期和印支晚期金矿床分区成带产出,构成一条复合型造山型金矿带。区域性构造导矿、次级构造交汇或叠加控矿明显;矿石普遍发育条带状构造,属韧性剪切递进变形的产物。通过对区域成矿背景、金矿成矿理论,金矿床(体)地质特征,结合同位素地球化学、地质找矿成果及深部验证情况等多方面研究表明该成矿带深部找矿潜力巨大,2000 m以浅金远景资源量有望达到3000 t。  相似文献   

渭河盆地地温场分布规律及其控制因素     

任战利  刘润川  任文波  祁凯  杨桂林  崔军平  杨鹏  张园园 《地质学报》2020,94(7):1938-1949

本文以渭河盆地地温场为研究对象,在收集补充新地热井资料及分析测试样品的基础上,通过盆地深部结构、构造特征、地温场特征、热储层特征、地热资源量等分析,建立了盆地不同岩性岩石热导率与深度关系图版,确定了盆地地温场变化规律及地热田控制因素,提出了渭河盆地地热田形成模式。评价了盆地地热资源有利区,为盆地后续的开发利用提供了理论支持。研究认为渭河盆地热地温梯度分布在2.34～5.85℃/100m之间,平均地温梯度为3.50℃/100m,代表性大地热流68.33mw/m~2,地温梯度及不同深度地层温度具有东高西低、南高北低的特点。热导率总体上具有随深度的增加,逐渐增大的规律,热导率随深度增加主要受压实程度增强控制。相同深度条件下泥岩热导率最低,砂岩热导率居中、白云岩热导率最高。渭河盆地主要为层状地热田,盆地内地热通过热传导及热对流两种方式进行传递,以热传导为主。渭河盆地地热资源丰富,热储层可分为三种类型:①新生界砂岩孔隙型;②下古生界碳酸盐岩岩溶型;③断裂型。渭河盆地地热资源有利区主要分布于西安凹陷、固市凹陷。盆地地温场及地热田分布与莫霍面、软流圈上隆、岩石圈厚度减薄的深部背景密切相关,主要受地热传导和深大断裂热对流控制,是岩石圈深部结构、盆地构造、基底岩性、储盖组合等多因素共同作用下形成的。最后结合当前渭河盆地地热资源开发利用现状及存在问题,提出了地热开发利用建议。  相似文献   

浅析广安华蓥山区山水林田湖综合治理措施——以高顶山矿区为例     

李飞  裴云婧  王维  李德星  张春茂 《四川地质学报》2020,40(1):80-85

高顶山矿区位于广安华蓥市城区东南约5km处。长期的采矿活动,导致区内矿山地质环境问题突出,严重影响华蓥山地区人民的生命财产安全。矿山地质环境问题亟待解决。本文通过分析区内主要存在的矿山地质环境问题,提出通过矿山地质灾害、矿山土地恢复、矿山地形地貌景观恢复治理,河道综合整治、道路修复、生态保育、产业提升等措施;消除安全隐患,保障区内人民生命财产安全;改善生态环境,实现华蓥山地区生态环境全面恢复,生态环境质量提升,提高环境承载力,实现区内"山青、水秀、林美、田良"的目标。并对区内的产业转型升级进行了探讨,提出将高顶山矿区建设成具有科普和教育价值的旅游景观目的地;利用矿区独具特色工业人文景观和别致的自然景观,将高顶山矿区建设成集"科普、休闲、康养、户外、探秘"五大功能于一体的矿山公园,推动矿业经济转型升级,促进产业结构转型和经济社会可持续发展。  相似文献