Dissolved organic matter dynamics during the spring snowmelt at a boreal river valley mire complex in Northwest Russia          下载免费PDF全文

Armine Avagyan  Benjamin R. K. Runkle  Nina Hennings  Hannes Haupt  Tarmo Virtanen  Lars Kutzbach 《水文研究》2016,30(11):1727-1741

Boreal mire landscapes are rich in soil carbon and significantly contribute to the carbon input of aquatic ecosystems. They are composed of different mesoscale ecohydrological subunits, whose individual contributions to the water and carbon export of mire catchments are not well understood. The spring snowmelt period is the major hydrological event in the annual water cycle of the boreal regions and strongly influences the carbon flux between the terrestrial and aquatic systems. The aim of this study was (1) to provide a conceptual understanding of the spatial and temporal dynamics of the surface water chemistry along a swamp forest‐fen‐bog gradient during the snowmelt period, (2) to quantify the exported dissolved organic carbon (DOC) content in the runoff and (3) to identify the ecohydrological landscape unit that contributes most to DOC export during the snowmelt period in a heterogeneous mire complex in Northwest Russia. The highest DOC concentrations were detected in the swamp forest, and the lowest concentrations were observed at the treeless bog by the end of the snowmelt period (swamp forest: 37–43 mg l^?1, bog: 13–17 mg l^?1). During the spring snowmelt period, a significant amount (~1.7 g C m^?2) of DOC was transferred by the ~74 mm of runoff from the catchment into the river. Variability in the thawing periods led to differences in the relative contributions of each ecohydrological zone to the carbon export measured at a stream channel draining the studied part of the mire complex. An increased understanding of the variation in DOC concentrations and contributions from the mesoscale ecohydrological subunits to carbon export can help to predict the potential regional loss of DOC based on land cover type under climate change. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

泸州深层页岩气呼吸性地层井漏堵漏方法及对策分析——以Y101H3-4井为例          下载免费PDF全文

李奎 《探矿工程》2022,49(5):106-110

泸州深层页岩气储层埋深达4000 m,属于高压力地层,所钻遇石牛栏组地层岩性为含砂泥岩,本区内多口井钻遇高压裂缝气,溢流及井漏风险大,时常出现高套压事件;同时一些井存在采用高密度钻井液钻进至类似地层时发生漏失后又返吐的现象,给堵漏和钻进作业带来较大困难。针对该类呼吸性地层井漏,以Y101H3-4井为例,现场试验了一系列堵漏方法及措施,结果表明：常规堵漏工艺对呼吸性地层堵漏效果不佳,堵漏材料粒径难以匹配,易导致封门堵漏失败;针对同平台邻井实钻油气显示情况,合理降低钻井液密度有助于堵漏作业实施;油基水泥塞是解决此类呼吸性井漏最有效的工艺技术,但前提条件是确定合理钻井液密度,降低注水泥过程中的返吐量,防止水泥浆与钻井液直接接触污染。在泸州区块采取降密度+注油基水泥塞堵漏是解决呼吸性地层井漏的最佳方法,可快速解决该类地层的堵漏难题。  相似文献   

RS和GIS支持下的三江平原沼泽湿地动态变化研究   总被引：81，自引：19，他引：81  

汪爱华  张树清  何艳芬 《地理科学》2002,22(5):636-640

以景观生态学理论为基础，采用遥感（RS）和地理信息系统（GIS）相结合的方法，探讨了三江平原沼泽湿地的动态变化特征。结果表明，三江平原沼泽湿地主要分布在富锦、同江和抚远三个县（市），其总面积占全区总面积的51.42%;1980-2000年间三江平原沼泽湿地的分布面积显著下降，1980-1996年间沼泽湿地面积减少了51.33%，1996年之后减少速度明显下降。同时沼泽湿地景观的破碎化显著，斑块数量增加了46%，斑块密度净增加两倍。1980年、1996年、2000年景观的分维湿地面积变化较之全区变化不显著外，其它地区均发生较为显著的变化。  相似文献   

瑞典泥炭沼泽分布、利用与保护     

卜兆君 《世界地理研究》2007,16(3):99-105

瑞典是泥炭沼泽广布，泥炭沼泽学研究历史悠久的国家。基于实地考察、交流与文献整理，分析了瑞典泥炭沼泽分布与成因、泥炭沼泽研究、利用及保护状况。早期的瑞典沼泽学者在泥炭沼泽分类、演化及沼泽植物地理学研究等方面处于国际领先地位，对学科的发展做出了重大贡献。目前，瑞典在泥炭沼泽的利用与保护方面也走在世界的前列，特别是泥炭沼泽合理利用与保护及恢复并举，值得我国湿地管理部门借鉴。  相似文献   

THE STUDY ON LATENT AND SENSIBLE HEAT FLUX OVER MIRE IN THE SANJIANG PLAIN   总被引：3，自引：0，他引：3  

JIA Zhi-Jun ~    SONG Chang-Chun~  SUN Li~   《湿地科学》2006,4(1):13-20

Energy exchange is one of the most importantprocesses in wetland ecosystems,because it has agreat influence on temperature,water transport,plantgrowth,productivityetc.(Dennison and Berry,1989).On small scales,understanding of surface en-ergy exchange is n…  相似文献   

On the information of mire depositional environment     

马学慧  王荣芬 《中国地理科学(英文版)》1992,2(2):164-172

Mire is the product of the Quaternary. It mostly formed, developed and declined after the postglacial age. Therefore the chemical element analysis, spore-pollen analysis, 14C dating, mire plant determination for mire sediment, and the study on hierarchy relation of mire sediment, can provide a lot of information for restoring paleogeography, paleoclimate and environmental change. So some people called mire sediment-peat as "database of environment".  相似文献   

毛苔草植被对沼泽湿地蒸散发影响的试验研究     

郭跃东 《湿地科学》2008,6(3)

为了揭示毛苔草植被对沼泽湿地蒸散发的影响,采用野外蒸发桶观测的方法,2007年7月5日至8月8日,在三江平原对不同植物密度下的毛苔草（Carex lasiocarpa）沼泽湿地下垫面蒸散发进行了试验研究。结果表明,毛苔草植被的存在能够增加沼泽湿地下垫面的蒸散发;与野外植物密度相同的有植物桶的蒸散发量平均达到13．88mm／d,最大蒸散发量可达22．26mm／d,而无植物桶的蒸散发量平均仅为4．81mm／d;有植物桶的平均蒸散发量为无植物桶蒸散发量的2．9倍。毛苔草植物的密度越大,对沼泽湿地下垫面蒸散发增加的作用越大,但只有当毛苔草叶面积指数大于1．5时,下垫面的蒸散发量才会显著增加。太阳辐射和气象要素对毛苔草沼泽湿地蒸散发的影响与植物密度间的关系复杂,还需要进一步研究。  相似文献   

Rethinking climate change impacts on subsurface temperatures in a sub‐Antarctic mire affected by synoptic scale processes     

Werner Nel  Barend J. van der Merwe  K. Ian Meiklejohn 《地球表面变化过程与地形》2009,34(10):1446-1449

This paper presents the first high resolution temperature data from a small Agrostis magellanica mire on subantarctic Marion Island as part of an ongoing island‐wide monitoring project on subsurface ground temperature variability. Variations in ground temperatures were found to be directly linked to the passage of synoptic scale weather systems that influence thermal characteristics and heat fluxes especially in the upper 30 cm of the mire. Preliminary data published here suggest that shallow temperatures will be most affected by changes in synoptic climate that Marion Island is currently experiencing with an increase in average temperatures and a reduction in temperature variability with depth. This study proposes that to effectively detect the ecosystem responses to climate change in a maritime sub‐Antarctic environment the temporal scale of measurement needs to be at least on a diurnal scale to be effective. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

再论中国含煤岩系沉积学研究进展及发展趋势     

邵龙义  王学天  鲁静  王东东  侯海海 《沉积学报》2017,35(5):1016-1031

过去30年间,在层序地层学及旋回地层学等沉积学理论引入中国后,中国学者在含煤岩系沉积学研究方面取得了长足的进步,相继提出幕式聚煤作用、海侵过程成煤作用、海侵事件成煤作用以及超厚煤层的多阶段泥炭地叠加成因模式等基于层序地层学理论及可容空间概念的聚煤模式,并将可进行区域对比的等时性地层单元（层序）与传统岩相古地理研究相结合,重建中国各聚煤期等时性岩相古地理,进行富煤带及聚煤中心迁移规律分析。随着煤层气及煤系页岩气等非常规天然气勘探的不断深入,煤相及沉积有机相研究作为煤及泥质岩生烃潜力评价的重要方法重新受到关注。“含煤系统”概念将含煤盆地中各种地质信息进行融合与集成,包括古泥炭堆积的原始特征、含煤岩系的地层格架及煤层丰度、煤中硫含量与分布特征、煤变质程度或煤阶等。近年来,煤层作为“深时”古气候信息的载体,成为当前研究热点之一,特别是煤中丝质体含量可用来研究古泥炭地火灾事件及大气氧含量变化,米兰科维奇旋回理论作为一种有效的“深时”时间尺度度量方法,可用来研究古泥炭地的碳聚集速率及其所反映的净初级生产力与大气CO₂变化趋势。未来含煤岩系沉积学将会进一步加强研究不同构造背景下的含煤岩系层序地层格架样式、层序地层格架下的优质煤炭资源与煤系非常规天然气资源预测模式,以及煤层在地球长、短周期气候变化旋回中的地质意义。  相似文献   

氮肥对三江平原沼泽土氧化CH4的影响   总被引：4，自引：0，他引：4  

王长科  吕宪国  蔡祖聪  罗勇 《地理科学》2005,25(4):490-494

三江平原新鲜沼泽土添加不同量的NH₄HCO₃后,在25°C下进行了6次连续培养。首次在大气浓度CH₄(约1.8 μl/l)中培养时,供试沼泽土氧化大气CH₄速率与NH₄HCO₃的加入量成反比,表明NH₄⁺最初抑制沼泽土氧化大气浓度CH₄。第1次用高浓度CH₄(约8 000 μl/l)培养沼泽土时,铵态氮抑制供试沼泽土氧化高浓度CH₄,但随着培养的继续,铵态氮的抑制作用逐渐减弱,最终转变为促进供试沼泽土氧化高浓度CH₄。经过高浓度CH₄培养后,添加NH₄HCO₃的供试沼泽土氧化大气CH₄速率上升2.6~5倍,且与NH₄HCO₃的加入量呈正相关,表明铵态氮肥最初对沼泽土氧化CH₄的抑制作用已经转变为促进作用。铵态氮对沼泽土氧化大气浓度CH₄和高浓度CH₄的抑制作用都是短暂的,其长期作用将是促进沼泽土氧化CH₄。  相似文献