BIFoR FACE: Water–soil–vegetation–atmosphere data from a temperate deciduous forest catchment,including under elevated CO2     

A. Rob MacKenzie  Stefan Krause  Kris M. Hart  Richard M. Thomas  Phillip J. Blaen  R. Liz Hamilton  Giulio Curioni  Susan E. Quick  Angeliki Kourmouli  David M. Hannah  Sophie A. Comer-Warner  Nicolai Brekenfeld  Sami Ullah  Malcolm C. Press 《水文研究》2021,35(3):e14096

The ecosystem services provided by forests modulate runoff generation processes, nutrient cycling and water and energy exchange between soils, vegetation and atmosphere. Increasing atmospheric CO₂ affects many linked aspects of forest and catchment function in ways we do not adequately understand. Global levels of atmospheric CO₂ will be around 40% higher in 2050 than current levels, yet estimates of how water and solute fluxes in forested catchments will respond to increased CO₂ are highly uncertain. The Free Air CO₂ Enrichment (FACE) facility of the University of Birmingham's Institute of Forest Research (BIFoR) is the only FACE in mature deciduous forest. The site specializes in fundamental studies of the response of whole ecosystem patches of mature, deciduous, temperate woodland to elevated CO₂ (eCO₂). Here, we describe a dataset of hydrological parameters – seven weather parameters at each of three heights and four locations, shallow soil moisture and temperature, stream hydrology and CO₂ enrichment – retrieved at high frequency from the BIFoR FACE catchment.  相似文献   

Long-term precipitation and stream discharge records at seven forested experimental watersheds along a latitudinal transect in Japan: Jozankei,Kamabuchi, Takaragawa,Tsukuba, Tatsunokuchi-yama,Kahoku and Sarukawa     

Takanori Shimizu  Koji Tamai  Ikuhiro Hosoda  Shoji Noguchi  Yuji Kominami  Toshio Abe  Kenzo Kitamura  Ushio Kurokawa  Delphis F. Levia  Tayoko Kubota  Naoki Kabeya  Shin'ichi Iida  Tatsuhiko Nobuhiro  Shinji Sawano  Sho Iwagami  Akira Shimizu  Yoshio Tsuboyama 《水文研究》2021,35(10):e14376

This data note introduces a database of long-term daily total precipitation and stream discharge data for seven forested watersheds in Japan that have been continuously monitored by the Forestry and Forest Products Research Institute. Three of the watersheds started data collection in the 1930s. Forest cover across the sites ranges from cool to warm temperate regions with the latitude spanning from 31 to 44° N and annual precipitation ranging from 1200 to 3000 mm yr⁻¹. The effects of vegetation change via clearcutting, thinning and forest fire (among other stressors) on stream discharge can be analysed from the long-term observation sites. Moreover, this multi-site dataset allows for inter- and intra-site comparisons of annual water loss (difference of annual precipitation and stream discharge). These long-term datasets can provide comprehensive insights into the effects of climate change and other stressors on forested ecosystems, not only in Japan but across a spectrum of forest types, if combined with other long-term records from other forested watersheds across the world.  相似文献   

A longer-term perspective on soil moisture,groundwater and stream flow response to the 2018 drought in an experimental catchment in the Scottish Highlands     

Chris Soulsby  Bernhard Scheliga  Aaron Neill  Jean-Christophe Comte  Doerthe Tetzlaff 《水文研究》2021,35(6):e14206

The drought of summer 2018, which affected much of Northern Europe, resulted in low river flows, biodiversity loss and threats to water supplies. In some regions, like the Scottish Highlands, the summer drought followed two consecutive, anomalously dry, winter periods. Here, we examine how the drought, and its antecedent conditions, affected soil moisture, groundwater storage, and low flows in the Bruntland Burn; a sub-catchment of the Girnock Burn long-term observatory in the Scottish Cairngorm Mountains. Fifty years of rainfall-runoff observations and long-term modelling studies in the Girnock provided unique contextualisation of this extreme event in relation to more usual summer storage dynamics. Whilst summer precipitation in 2018 was only 63% of the long-term mean, soil moisture storage across much of the catchment were less than half of their summer average and seasonal groundwater levels were 0.5 m lower than normal. Hydrometric and isotopic observations showed that ~100 mm of river flows during the summer (May-Sept) were sustained almost entirely by groundwater drainage, representing ~30% of evapotranspiration that occurred over the same period. A key reason that the summer drought was so severe was because the preceding two winters were also dry and failed to adequately replenish catchment soil moisture and groundwater stores. As a result, the drought had the biggest catchment storage deficits for over a decade, and likely since 1975–1976. Despite this, recovery was rapid in autumn/winter 2018, with soil and groundwater stores returning to normal winter values, along with stream flows. The study emphasizes how long-term data from experimental sites are key to understanding the non-linear flux-storage interactions in catchments and the “memory effects” that govern the evolution of, and recovery from, droughts. This is invaluable both in terms of (a) giving insights into hydrological behaviours that will become more common water resource management problems in the future under climate change and (b) providing extreme data to challenge hydrological models.  相似文献   

沙漠微生物矿化覆膜及其稳定性的现场试验研究   总被引：2，自引：0，他引：2  

李驰  王硕  王燕星  高瑜  斯日古楞 《岩土力学》2019,40(4):1291-1298

将微生物诱导矿化技术应用于原位沙漠覆膜的形成,使得流动沙丘经结皮固定而成为半固定、固定沙丘,从根本上阻断沙尘暴的源头。在内蒙古乌兰布和沙漠腹地选择两个微生物矿化试验区域（TP1和TP3）,分别用于两种不同矿化菌种诱导生成碳酸钙覆膜。研究沙漠微生物矿化覆膜的现场试验方法及工艺,对原位矿化覆膜的强度及其在沙漠环境中的长期稳定性进行跟踪检测。采用沙漠土中自行提取的葡萄球菌和传统的巴氏芽孢杆菌两种不同的微生物矿化菌种,通过现场贯入试验检测7、14、28、60、210 d后矿化覆膜沿深度发展的贯入阻力,并将覆膜厚度为2 cm处的平均贯入阻力换算成覆膜层强度,总结覆膜强度随时间的发展变化规律。现场观测结果显示,不同微生物菌种诱导生成的矿化覆膜均在试验的第4天开始形成,到第7天覆膜层具有稳定的强度和厚度,现场检测覆膜的平均厚度为2.0～2.5 cm,经自源葡萄球菌诱导生成的矿化覆膜（TP1）的强度是巴氏芽孢杆菌诱导生成的矿化覆膜（TP3）强度的1.05倍。当经历冬春交替后覆膜层强度都有不同程度的降低,明显地TP3较TP1区域表面剥落更为严重,第210天检测TP3的平均厚度为0.7～1.0 cm,覆膜强度较第7天时降低19%,覆膜内碳酸钙含量较第7天检测时降低15%～30%。而TP1在第210天时的强度较第7天时强度降低仅2%。因此,微生物诱导矿化技术可以应用于沙漠原位覆膜的形成,且沙漠自源葡萄球菌经诱导生成的矿化覆膜层具有更好的强度表现和稳定性。  相似文献   

二叠系炭质页岩软弱夹层剪切蠕变特性研究   总被引：2，自引：0，他引：2  

朱赛楠  殷跃平  李滨 《岩土力学》2019,40(4):1377-1386

以西南灰岩山区二叠系炭质页岩软弱夹层为研究对象,开展了原生软岩、层间剪切带和滑带3个演化阶段的矿物组成成分、微结构和不同正应力水平的剪切蠕变力学特性分析。结果表明：软弱夹层在演化过程中,矿物组分发生改变,黏土矿物含量在原生软岩中小于5%,层间剪切带中在5%～10%之间,滑带中大于10%。微结构由致密变得疏松,颗粒间连接力减弱;软弱夹层的蠕变位移和蠕变速率随着剪应力增加而增大,呈非线性关系。在相同剪应力条件下,蠕变位移和蠕变速率的关系为：滑带>层间剪切带>原岩。长期剪切强度逐渐降低,黏聚力的降幅大于内摩擦角,对时间的敏感程度较高。为受软弱夹层控制的层状基岩滑坡的发育发展过程、失稳机制研究提供了重要借鉴意义。  相似文献   

Long-term hydrology and aquatic biogeochemistry data from H. J. Andrews Experimental Forest,Cascade Mountains,Oregon     

Sherri L. Johnson  Don Henshaw  Greg Downing  Steve Wondzell  Mark Schulze  Adam Kennedy  Greg Cohn  Stephanie A. Schmidt  Julia A. Jones 《水文研究》2021,35(5):e14187

The H. J. Andrews Experimental Forest (HJA) encompasses the 6400 ha Lookout Creek watershed in western Oregon, USA. Hydrologic, chemistry and precipitation data have been collected, curated, and archived for up to 70 years. The HJA was established in 1948 to study the effects of harvest of old-growth conifer forest and logging-road construction on water quality, quantity and vegetation succession. Over time, research questions have expanded to include terrestrial and aquatic species, communities and ecosystem dynamics. There are nine small experimental watersheds and 10 gaging stations in the HJA, including both reference and experimentally treated watersheds. Gaged watershed areas range from 8.5 to 6242 ha. All gaging stations record stage height, water conductivity, water temperature and above-stream air temperature. At nine of the gage sites, flow-proportional water samples are collected and composited over 3-week intervals for chemical analysis. Analysis of stream and precipitation chemistry began in 1968. Analytes include dissolved and particulate species of nitrogen and phosphorus, dissolved organic carbon, pH, specific conductance, suspended sediment, alkalinity, and major cations and anions. Supporting climate measurements began in the 1950s in association with the first small watershed experiments. Over time, and following the initiation of the Long Term Ecological Research (LTER) grant in 1980, infrastructure expanded to include a set of benchmark and secondary meteorological stations located in clearings spanning the elevation range within the Lookout Creek watershed, as well as a large number of forest understory temperature stations. Extensive metadata on sensor configurations, changes in methods over time, sensor accuracy and precision, and data quality control flags are associated with the HJA data.  相似文献   

Snowmelt characteristics in a pristine mountain catchment of the Jalovecký Creek,Slovakia, over the last three decades     

Ladislav Holko  Michal Danko  Patrik Sleziak 《水文研究》2021,35(4):e14128

The Jalovecký Creek catchment, Slovakia (area 22.2 km², mean elevation 1500 m a.s.l.), is likely the last big valley complex in the Carpathian Mountains, in which the hydrological cycle is still governed by natural processes. Hydrological research is conducted there since the end of the 1980s. The overall mission of the research is to increase the knowledge about the hydrological cycle in the highest part of the Carpathians. The research agenda, briefly introduced in the first part of this article, is focused on water balance, snow accumulation and melt and runoff formation. Recent analysis of precipitation, discharge, snow cover and isotopic data from period 1989–2018 indicates that hydrological cycle has become more dynamic since 2014. Although several indicators suggest that it could be related to the cold part of the year, direct links with snow storage and the contribution of snowmelt water to catchment runoff were not confirmed. The second part of the article is therefore focused on an analysis of daily cycles in streamflow in March to June 1988–2018 to obtain a deeper insight into the snowmelt process. We describe characteristics of the cycles and examine their variability over the study period. The results indicate that less snow at the lowest elevations (800–1150 m a.s.l.) since 2009 could have influenced the cessation of the cycles in June since 2010. The possible role of the decreased amount of snow at the lowest elevations in changes in runoff characteristics is also suggested by an increase in time lags between maximum discharges during the events and maximum air temperatures preceding discharge maxima measured near the catchment outlet (at 750 m a.s.l.) in spring 2018 compared to springs with a similar number of streamflow cycles in the years 1988, 2000 and 2009. Wavelet analysis did not indicate changes in global power spectra in hourly discharge and air temperature data.  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   

北京地区城市热岛强度长期变化特征及气候学影响机制     

黄群芳  陆玉麒 《地理科学》2018,38(10):1715-1723

选择北京地区为研究区,基于1967~2016年城市站（北京站）和城郊农村站（密云站）的长期气象观测数据,研究平均气温、最高气温、最低气温对应的城市热岛强度长期变化特征及其气候学影响机制。研究发现,过去50 a平均气温和最低气温对应的城市热岛强度显著增加,增温率分别为0.29℃/10a和0.45℃/10a,而最高气温对应的城市热岛强度则没有明显变化趋势;统计分析显示过去50 a北京地区相对湿度、风速和日照时数显著降低以及气温显著上升有利于城市热岛的形成,强化城市热岛强度;未来全球变暖和快速城市化背景下北京地区城市热岛效应将进一步加剧,形成更频繁和持续时间更长的夏季城市高温热浪,严重危及城市居民生产生活和生命健康。  相似文献   

西安地区旱涝气候的长期变化   总被引：3，自引：2，他引：1  

李兆元  吴素良  杨文峰  陈建文  王玉玺  余兴 《气候与环境研究》1997,2(4):356-360

根据西安丰富的历史旱涝史料,建立了近１５００年旱涝序列,并采用滑动滤波、功率谱分析、谐波分析等方法,对西安地区旱涝气候的长期变化进行分析。  相似文献