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   

Hammond Hill Research Catchment: Supporting hydrologic investigations of rooting zone and vegetation water dynamics under climate change     

James Knighton  Kanishka Singh  Valessa Souter-Kline  M. Todd Walter 《水文研究》2020,34(24):4755-4758

The Hammond Hill Research Catchment (HH) is a small (120 ha), temperate, second order tributary to Six Mile Creek, Cayuga Lake, and the Great Lakes (42.42°, −76.32°). The HH has been monitored since January 2017 for the purpose of understanding how recent infiltration mixes with antecedent soil water on hillslope forest floors and the spatial and temporal patterns of Root Water Uptake (RWU) by temperate northeastern US tree species (eastern hemlock [Tsuga canadensis], American beech [Fagus grandifolia], and sugar maple [Acer saccharum]). These data are informing us about the hydrologic consequences of anticipated tree species composition change and supporting the development of more refined ecohydrological models. The glaciated catchment is underlain by a shallow confining siltstone layer (1–1.5 m depth) and densely covered with an approximately 60 year old regrowth mixed species forest of hemlock, beech, and other deciduous tree species common to the northeastern US. Current datasets from the HH include precipitation snow water equivalent, discharge, and associated isotopic water compositions, δ²H & δ¹⁸O. Measurements of (top 10 cm) soil water content, as well as bulk soil water and hemlock and beech xylem isotopic compositions are made at several locations across a topographic wetness gradient. The near-term role of the HH is to support an understanding of the environmental and ecological drivers of plant RWU competition. All data from the HH are publicly available.  相似文献   

微型全极化SAR海洋监测应用技术研究     

王军锋  乔明  刘子畅  吕大勇 《测绘与空间地理信息》2020,(2):88-90

我国作为海洋大国,近年来海洋事业进入快速发展时期,合成孔径雷达以其自身的技术特点在海洋遥感监测中发挥了重要的作用。在以往的海洋监测中大多采用星载合成孔径雷达获取海洋数据,但因星载SAR受到卫星搭载平台和运行轨道等因素影响,对局部地区高时效的数据获取还存在一定的制约因素。本文通过对无人机机载微型全极化合成孔径雷达对海岸带、海岛礁、海洋动目标高分辨率成像和应用分析研究,为无人机机载SAR在海洋监测中的应用提供了全新的技术手段。  相似文献   

中国工业烟粉尘排放时空演化及其影响因素     

郭政  姚士谋  吴常艳 《地理科学》2020,40(12):1949-1957

采用空间分析和空间杜宾模型等方法，研究1999—2017年中国工业烟粉尘排放时空演化特征及其影响因素。结果表明：① 中国工业烟粉尘排放空间分布差异明显，其排放的基尼系数和污染物分布指数均呈现下降态势，空间集中程度有所缓和。② 中国工业烟粉尘排放空间分布呈东北?西南走向，其排放中心不断由东南向西北方向迁移。③ 中国工业烟粉尘排放存在空间相关性和空间溢出效应，其冷热点区空间分布发生显著变化。④ 能源消耗、第二产业比重、人口密度和经济发展水平的提升将会增加工业烟粉尘排放，而外资水平、治理技术水平和环境规制力度的提升则有利于减少工业烟粉尘排放。  相似文献   

地方政府土地出让干预对区域工业碳排放影响的对比分析——以中国8大经济区为例     

王博  吴天航  冯淑怡 《地理科学进展》2020,39(9):1436-1446

探讨不同区域地方政府干预对碳排放的影响差异,对于中国推进碳减排战略、协调区域经济社会发展具有重要意义。鉴于此,论文基于地方政府土地出让的视阈,以中国8大经济区为研究对象,有机耦合STIRPAT模型与CKC模型,构建形成STIRPAT拓展模型,并使用2007—2016年中国28个省(市、自治区)的工业面板数据,对比考察8大经济区政府土地出让干预对区域碳排放的影响差异。结果表明:不同经济区的地方政府土地出让干预对区域碳排放的影响存在显著差异。其中,同为CKC“倒N”型的北部沿海、南部沿海、长江中游经济区,其政府土地出让干预对区域碳排放的影响呈现出北部沿海经济区为负、南部沿海经济区为正、长江中游经济区无显著影响的差异效果;同为CKC“倒U”型的东北、西南和西北经济区,其政府土地出让干预对区域碳排放的影响,东北和西南经济区都显著为负,西北经济区未表现出显著影响;同为CKC“U”型的东部沿海和黄河中游经济区,其政府土地出让干预对碳排放也呈现出前者为负、后者为正的相反影响。研究结果可为制定碳减排差别化政策、协调区域可持续发展提供参考。  相似文献   

喀喇昆仑山西北部冰川运动速度地形控制特征   总被引：2，自引：2，他引：0  

张莎莎  张震  刘时银  李鑫  黄丹妮  薛乃婷 《冰川冻土》2019,41(5):1015-1025

为了探讨地形和海拔对冰川季节和年平均运动速度的影响程度，利用2013-2018年GoLive数据与ASTER GDEM V2数据对喀喇昆仑山西北部3 389条冰川的地形（坡度、坡向、海拔）和冰川运动速度进行了综合分析。结果表明：冰川表面运动速度在物质平衡线处（3 970~4 770 m）达到最快，是冰川积极维持物质平衡的一种体现。坡度平缓地区在不同海拔下的冰川运动速度有明显的差别，但是不同坡度地区的冰川运动速度随海拔变化的趋势基本一致，均呈现先增大后减小。北坡冰川运动速度较平稳，南坡和西南坡的冰川运动速度（均为0.25 m·d^-1）最快并且变化幅度较大，最小值与最大值相差近4倍。冰川运动速度不是呈现单一的季节性变化，同时还会受到地形的控制。低海拔区域冰川运动速度在消融期（3-6月）较快，中海拔区域在消融前（11月至次年2月）较快。  相似文献   

Atmospheric Reactive Nitrogen Cycle and Stable Nitrogen Isotope Processes: Progresses and Perspectives   总被引：1，自引：1，他引：0  

Tao Zhou  Zhuang Jiang  Lei Geng 《地球科学进展》2019,34(9):922-935

Oxidized reactive nitrogen in the atmosphere mainly consists of nitrogen oxides (NO _X =NO+NO₂, NO₃) and nitric acid. The atmospheric cycling of NO _X influences the formation of ozone and hydroxyl radicals that are important for atmospheric oxidation capacity. Nitric acid, the final product of NO _X oxidation, not only is an important component of particulate pollutants, but also has a direct impact on the ecosystem through dry and wet deposition. The stable nitrogen isotope (δ¹⁵N) shows the potential to study reactive nitrogen cycle, and to trace the emission, transport and deposition of reactive nitrogen from local to global scales. Here, we reviewed previous studies using δ¹⁵N to investigate NO _X emission and atmospheric reactive nitrogen cycle, and discuss the uncertainties of δ¹⁵N signatures of different NO _X sources from two aspects: NO _X generation mechanism and NO _X collection methods. We also discussed the nitrogen isotope fractionation and the consequences during the conversions of NO _y molecules. We ended up with discussions on the possibility of using δ¹⁵N to trace NO _X emissions. Although there are still large uncertainties in quantifying and tracing NO _X emissions using nitrogen stable isotopes, such isotope tool is efficient enough to trace reactive nitrogen cycles in the atmosphere. On the basis of this, we proposed that we can combine atmospheric chemistry transmission models with isotope tracers to improve our understanding of regional and global atmospheric reactive nitrogen cycle regarding the fluxes of different emission sources, their atmospheric transformation, etc.  相似文献   

分布式光纤声波传感器及其在天然地震学研究中的应用     

张丽娜  任亚玲  林融冰  宋政宏  曾祥方 《地球物理学进展》2020,(1):65-71

分布式光纤声波传感器(Distributed Acoustic Sensing,DAS)是近年来兴起的超密集地震观测系统,具有一系列观测密度高、观测成本低、耐受恶劣环境等优势,在油气行业得到了广泛应用,也引起了天然地震学界的关注.本文简要回顾了DAS系统的测量原理、发展历程、技术方案、介绍了测量原理及其响应特性,然后围绕多个观测实验,介绍浅部结构成像、深部结构探测和地震监测三个方向的典型应用实例,最后讨论了DAS系统在天然地震学研究中应用面临的挑战和发展趋势.  相似文献   

基于虚拟现实技术的排水管道损伤粘合修复方法          下载免费PDF全文

于泰然  田爽  张晗 《探矿工程》2020,47(7):106-111

传统的地下排水管道损伤粘合修复方法修复后外渗较多，为了解决这一问题，基于虚拟现实技术提出了一种新的排水管道损伤粘合修复方法，通过负压波形图法定位排水管道的损伤位置和损伤程度，然后通过通信模拟器进行排水管道损伤信号的输送，计算机输出排水管道的损伤鉴定，采用虚拟仿真技术，应对不同损伤程度的排水管道，合理地进行粘合修复处理。结果表明，与传统修复方法相比，基于虚拟现实技术的排水管道损伤粘合修复材料更加合理，在修复后会通过特殊试剂进行清洗，提高了排水管道损伤处的粘合效果，降低排水管道损伤粘合修复后的外渗量。  相似文献   

A review of fully coupled atmosphere-hydrology simulations     

Ning  Like  Zhan  Chesheng  Luo  Yong  Wang  Yueling  Liu  Liangmeizi 《地理学报(英文版)》2019,29(3):465-479

Journal of Geographical Sciences - The terrestrial hydrological process is an essential but weak link in global/regional climate models. In this paper, the development status, research hotspots and...  相似文献