An overview of hydrometeorological datasets from a small agricultural catchment (Nučice) in the Czech Republic     

Tailin Li  Jakub Jeřábek  Nina Noreika  Tomáš Dostál  David Zumr 《水文研究》2021,35(2):e14042

We introduce the freely available web-based Water in an Agricultural Landscape—NUčice Database (WALNUD) dataset that includes both hydrological and meteorological records at the Nučice experimental catchment (0.53 km²), which is representative of an intensively farmed landscape in the Czech Republic. The Nučice experimental catchment was established in 2011 for the observation of rainfall–runoff processes, soil erosion processes, and water balance of a cultivated landscape. The average altitude is 401 m a.s.l., the mean land slope is 3.9%, and the climate is humid continental (mean annual temperature 7.9°C, annual precipitation 630 mm). The catchment is drained by an artificially straightened stream and consists of three fields covering over 95% of the area which are managed by two different farmers. The typical crops are winter wheat, rapeseed, and alfalfa. The installed equipment includes a standard meteorological station, several rain gauges distributed across the basin, and a flume with an H-type facing that is used to monitor stream discharge, water turbidity, and basic water quality indicators. Additionally, the groundwater level and soil water content at various depths near the stream are recorded. Recently, large-scale soil moisture monitoring efforts have been introduced with the installation of two cosmic-ray neutron sensors for soil moisture monitoring. The datasets consist of observed variables (e.g. measured precipitation, air temperature, stream discharge, and soil moisture) and are available online for public use. The cross-seasonal, open access datasets at this small-scale agricultural catchment will benefit not only hydrologists but also local farmers.  相似文献   

Hydrological trends and the evolution of catchment research in the Alptal valley,central Switzerland     

Manfred Stähli  Jan Seibert  James W. Kirchner  Jana von Freyberg  Ilja van Meerveld 《水文研究》2021,35(4):e14113

When the observation of small headwater catchments in the pre-Alpine Alptal valley (central Switzerland) started in the late 1960s, the researchers were mainly interested in questions related to floods and forest management. Investigations of geomorphological processes in the steep torrent channels followed in the 1980s, along with detailed observations of biogeochemical and ecohydrological processes in individual forest stands. More recently, research in the Alptal has addressed the impacts of climate change on water supply and runoff generation. In this article, we describe, for the first time, the evolution of catchment research at Alptal, and present new analyses of long-term trends and short-term hydrologic behaviour. Hydrometeorological time series from the past 50 years show substantial interannual variability, but only minimal long-term trends, except for the ~2°C increase in mean annual air temperature over the 50-year period, and a corresponding shift towards earlier snowmelt. Similar to previous studies in larger Alpine catchments, the decadal variations in mean annual runoff in Alptal's small research catchments reflect the long-term variability in annual precipitation. In the Alptal valley, the most evident hydrological trends were observed in late spring and are related to the substantial change in the duration of the snow cover. Streamflow and water quality are highly variable within and between hydrological events, suggesting rapid shifts in flow pathways and mixing, as well as changing connectivity of runoff-generating areas. This overview illustrates how catchment research in the Alptal has evolved in response to changing societal concerns and emerging scientific questions.  相似文献   

The Fernow Experimental Forest,West Virginia,USA: Insights,datasets, and opportunities     

Luis Andrés Guillén  Mary Beth Adams  Emily Elliot  Jason Hubbart  Charlene Kelly  Brenden McNeil  William Peterjohn  Nicolas Zegre 《水文研究》2021,35(4):e14106

Long-term experimental watershed studies have significantly influenced our global understanding of hydrological processes. The discovery and characterization of how stream water quantity and quality respond to a changing environment (e.g. land-use change, acidic deposition) has only been possible due to the establishment of catchments devoted to long-term study. One such catchment is the Fernow Experimental Forest (FEF) located in the headwaters of the Appalachian Mountains in West Virginia, a region that provides essential freshwater ecosystem services to eastern and mid-western United States communities. Established in 1934, the FEF is among the earliest experimental watershed studies in the Eastern United States that continues to address emergent challenges to forest ecosystems, including climate change and other threats to forest health. This data note describes available data and presents some findings from more than 50 years of hydrologic research at the FEF. During the first few decades, research at the FEF focused on the relationship between forest management and hydrological processes—especially those related to the overall water balance. Later, research included the examination of interactions between hydrology and soil erosion, biogeochemistry, N-saturation, and acid deposition. Hydro-climatologic and water quality datasets from long-term measurements and data from short-duration studies are publicly available to provide new insights and foster collaborations that will continue to advance our understanding of hydrology in forested headwater catchments. As a result of its rich history of research and abundance of long-term data, the FEF is positioned to continue to advance understanding of forest ecosystems in a time of unprecedented change.  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   

基于邻域约束聚类的地球化学异常提取     

杨昭颖  冯磊  姜德才  朱月琴  余先川 《地质通报》2019,38(12):2077-2084

通过分析地球化学数据的元素值属性和空间位置，提出一种基于邻域约束聚类的方法，使用该方法对地球化学元素聚类后，能提取矩形、环状、半环状等特殊形状，进而提取地球化学异常。选取河南崤山地区2个实验区的地球化学数据进行实验，实验一的结果表明，出现矩形的位置与已知钨矿矿点位置一致；实验二的结果表明，出现环形的位置与已知铜矿矿点位置一致。实验证明了基于邻域约束聚类的方法在提取地球化学异常方面的有效性。  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   

Variation in the vertical zonality of erodibility and critical shear stress of rill erosion in China's Hengduan Mountains     

Zhengan Su  Donghong Xiong  Jianhui Zhang  Tao Zhou  Hongkun Yang  Yifan Dong  Haidong Fang  Liangtao Shi 《地球表面变化过程与地形》2019,44(1):88-97

Soil erodibility is an essential parameter used in soil erosion prediction. This study selected the Liangshan town watershed to quantify variation in the vertical zonality of rill erodibility (k_r) in China's ecologically fragile Hengduan Mountains. Soil types comprised of yellow–brown (soil A), purple (soil B), and dry-red (soil C) in a descending order of occurrence from the summit to the valley, which roughly corresponds to the vertical climate zone (i.e. cool-high mountain, warm-low mountain, and dry-hot valley sections) of the study area. With elevation, vertical soil zonality varied in both soil organic matter (SOM) content and soil particle-size fractions. A series of rill erosion-based scour experiments were conducted, using water discharge rates of 100, 200, 300, 400, 500, and 600 mL min^-1. Additionally, detachment rates (Dr) were measured under three hydrological conditions (the drainage, saturation, and seepage treatments). Results show that both Dr and flow shear stress (Ʈ) values increased as discharge increased. As elevation increased, the k_r values decreased, while the vertical zonality of critical shear stress (Ʈ_c) values showed no obvious variation. The highest k_r values were observed during the seepage treatment, followed by the saturation treatment then drainage treatment, indicating that variation in vertical hydraulic gradients could significantly alter k_r values. This study also found that land-use types could also alter k_r and Ʈ_c values. Further research, however, is necessary to better quantify the effects of subsurface hydrological conditions and land-use types on k_r under different soil zonalities in China's Hengduan Mountains. © 2018 John Wiley & Sons, Ltd.  相似文献