It’s Time To Learn About Learning: Where Should the Environmental and Natural Resource Governance Field Go Next?     

Andrea K. Gerlak  Tanya Heikkila  Sharon L. Smolinski  Derek Armitage  Dave Huitema  Brendan Moore 《社会与自然资源》2019,32(9):1056-1064

This Commentary reflects on the state of the scholarship on learning for environmental and natural resource policy and governance. How have we been learning about learning? We highlight theoretical and empirical advancements related to learning, as well as areas of divergence between learning theories and frameworks, and underdeveloped knowledge around processes and outcomes. To address these limitations and improve progress in both theory and practice, we offer recommendations for learning scholarship by focusing on how to collectively engage in ‘learning about learning’.  相似文献   

Rainfall interception of typical ecosystems in the Heihe River Basin: Based on high temporal resolution soil moisture data   总被引：1，自引：1，他引：0  

Yang  Chongyao  Huang  Yongmei  Li  Engui  Li  Zeqing 《地理学报(英文版)》2019,29(9):1527-1547

Journal of Geographical Sciences - Rainfall interception is of great significance to the fully utilization of rainfall in water limited areas. Until now, studies on rainfall partitioning process of...  相似文献   

Effects of heavy metal pollution on farmland soils and crops: A case study of the Xiaoqinling Gold Belt,China   总被引：1，自引：0，他引：1  

《China Geology》2020,3(3):402-410

This paper focuses on the heavy metal enrichment and heavy metal pollution degree associated with mining activities in some crops and the soils of different parent materials in the Xiaoqinling Gold Belt. According to the geochemical analysis results of the soils observed in the gold belt, the soils are most highly enriched in Pb, followed by Cr, Cu, and Zn. Furthermore, they are relatively poor in Hg, Cd, and As. It is also shown that the heavy metals in all kinds of soils have the same geochemical characteristics in the gold belt. As for the crops (such as corn and wheat) in the gold belt, Zn and Cu are the most abundant elements, followed by Pb and Cr. Meanwhile, Hg, Cd, and As were found to have relatively low concentrations in the crops. The heavy metals in wheat and corn have the same geochemical characteristics in the gold belt in general. Compared to the aeolian loess soils and the crops therein, heavy metals are more enriched in diluvial and alluvial soils and the crops therein. As shown by relevant studies, the Hg, Pb, Cd, Cu, and Zn pollution are mainly caused by mining activities. Corn and wheat in the gold belt have a high tendency of risk exposure to heavy metal pollution since they are mostly affected by mining activities and feature high background values of heavy metal concentrations. Furthermore, wheat is more liable to be enriched in heavy metals than corn is grown in all types of soils. The Hg pollution in soils leads to Hg accumulation, increasing the risk of Hg uptake in crops, and further affecting human health. This study will provide a scientific basis for the control and management of heavy metals in farmland soils of mining areas.  相似文献   

贵州省赫章县核桃农业园区富硒土地特征及开发建议   总被引：1，自引：0，他引：1       下载免费PDF全文

陆光艳  袁彬  黄林  孟庆田  任厚州 《贵州地质》2020,37(3):258-265

针对单一角度采集的图像检测样本存在的高误检率、错误率等问题，文章提出一种特殊的打光方案及相机安装方案，实现对胶囊360°全方位的缺陷检测,利用彩色相机填补了胶囊异色点、黑点，印字、小切口以及混批等缺陷不能检测的空白。在胶囊有序传送的前提下，提出“隔组间排”原理，以更多时间和空间使电磁铁伸缩杆完成踢废动作，平衡“传送效率”“检测效率”“踢废效率”三者之间的矛盾，提高设备的处理能力，实现胶囊的缺陷检测。  相似文献   

Long-term hydrological,biogeochemical, and climatological data from Walker Branch Watershed,East Tennessee,USA     

Natalie A. Griffiths  Patrick J. Mulholland 《水文研究》2021,35(3):e14110

In 1967, the original Walker Branch Watershed (WBW) project was established to study elemental cycling and mass balances in a relatively unimpacted watershed. Over the next 50+ years, findings from additional experimental studies and long-term observations on WBW advanced understanding of catchment hydrology, biogeochemistry, and ecology and established WBW as a seminal site for catchment science. The 97.5-ha WBW is located in East Tennessee, USA, on the U.S. Department of Energy's Oak Ridge Reservation. Vegetation on the watershed is characteristic of an eastern deciduous, second-growth forest. The watershed is divided into two subcatchments: the West Fork (38.4 ha) and the East Fork (59.1 ha). Headwater streams draining these subcatchments are fed by multiple springs, and thus flow is perennial. Stream water is high in base cations due to weathering of dolomite bedrock and nutrient concentrations are low. Long-term observations of climate, hydrology, and biogeochemistry include daily (1969–2014) and 15-min (1994–2014) stream discharge and annual runoff (1969–2014); hourly, daily, and annual rainfall (1969–2012); daily climate and soil temperature (1993–2010); and weekly stream water chemistry (1989–2013). These long-term datasets are publicly available on the WBW website (https://walkerbranch.ornl.gov/long-term-data/ ). While collection of these data has ceased, related long-term measurements continue through the National Ecological Observatory Network (NEON), where WBW is the core terrestrial and aquatic site in the Appalachian and Cumberland Plateau region (NEON's Domain 7) of the United States. These long-term datasets have been and will continue to be important in evaluating the influence of climatic and environmental drivers on catchment processes.  相似文献   

A hydropedological approach to simulate streamflow and soil water contents with SWAT+     

Johan van Tol  Katrin Bieger  Jeffrey G. Arnold 《水文研究》2021,35(6):e14242

Reflecting internal catchment hydrological processes in hydrological models is important for accurate predictions of the impact of climate and land-use change on water resources. Characterizing these processes is however difficult and expensive due to their dynamic nature and spatio-temporal variability. Hydropedology is a relatively new discipline focusing on the synergistic integration of hydrology, soil physics and pedology. Hydropedological interpretations of soils and soil distribution can be used to characterize key hydrological processes, especially in areas with no or limited hydrometric measurements. Here we applied a hydropedological approach to reflect flowpaths through detailed routing in SWAT+ for a 157 ha catchment (Weatherley) in South Africa. We compared the hydropedological approach and a standard (no routing) approach against measured streamflow (two weirs) and soil water contents (13 locations). The catchment was treated as ‘ungauged’ and the model was not calibrated against hydrometric measurements in order to determine the direct contribution of hydropedology on modelling efficiency. Streamflow was predicted well without calibration (NSE > 0.8; R² > 0.82) for both approaches at both weirs. The standard approach yielded slightly better streamflow predictions. The hydropedological approach resulted in considerable improvements in the simulation of soil water contents (R² increased from 0.40 to 0.49 and PBIAS decreased from 40% to 20%). The routing capacity of SWAT+ as employed in the hydropedological approach reduced the underestimation of wetland water regimes drastically and resulted in a more accurate representation of the dominant hydrological processes in this catchment. We concluded that hydropedology can be a valuable source of ‘soft data’ to reflect internal catchment structure and processes and, potentially, for realistic calibrations in other studies, especially those conducted in areas with limited hydrometric measurements.  相似文献   

River discharge,land use change,and surface water quality in the Xiangjiang River,China          下载免费PDF全文

Zhao Zhang  Yi Chen  Pin Wang  Jiabing Shuai  Fulu Tao  Peijun Shi 《水文研究》2014,28(13):4130-4140

To compare the impacts of river discharge on the surface water quality of the Xiangjiang River in China, 12 surface water quality parameters recorded at 31 sampling sites from January 1998 to December 2008 along the river and its main tributaries were analyzed. Significantly higher concentrations of total nitrogen, ammoniacal nitrogen, and total phosphorus, and biochemical oxygen demand were observed during low‐flow periods than during high‐flow periods, implying a higher risk to local residents drinking untreated water during low‐flow periods. Pollution indexes, including the inorganic pollution index and integrated pollution index (IPI), were negatively related to impervious surface area (ISA) and cropland area (CLA) when ISA (CLA) was less than 160 (3000) km². However, the relationship was positive when ISA (CLA) was larger than 160 (3000) km², which provided a reasonable explanation for the observed spatial patterns of water quality. Distinct increasing temporal trends for two kinds of pollution indexes were also found. The annual ISA was significantly related to the rapid degradation of water quality from 1998 to 2008, with correlation coefficient (r) values of 0.816 (p = 0.002) and 0.711 (p = 0.014) for the organic pollution index (OPI) and IPI, respectively. However, annual rainfall was negatively correlated with the two indexes with r values of 0.785 (p = 0.002) and 0.448 (p = 0.093) for OPI and IPI, respectively. Our study highlights that decision makers should be more aware of recent increases in the pollution of the Xiangjiang River, especially at downriver sites and during low‐flow periods. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

汞同位素地球化学研究及其在矿床学中的应用进展     

徐春霞  孟郁苗  黄诚  唐春  郑芳文 《岩矿测试》2021,(2):173-186

汞作为一种重要的成矿元素,广泛分布于不同地质体中,并参与成岩成矿作用。随着质谱技术的飞跃发展,汞同位素地球化学研究取得引人瞩目的进展。汞同位素被广泛地应用于示踪地球表生生物地球化学过程及汞污染等。近年来,汞同位素又被应用于揭示行星的演化过程、识别地质历史时期大火成岩省及示踪矿床成矿物质来源等方面。本文在前人研究的基础上,对不同地质储库汞同位素组成进行了系统总结。陨石、岩浆岩、变质岩、沉积岩、火山气体等地质储库汞同位素组成变化较大,部分样品还显示非质量分馏信息。本文着重阐述了低温热液矿床(现代热泉、汞矿床、铅锌矿床、锑矿床、金矿床)汞的赋存状态及同位素组成特征,构筑了汞同位素体系的基本格架。结合最新的研究成果,较全面地总结了矿床成矿过程中可能会发生的汞同位素分馏机制。热液矿床中汞同位素的质量分馏可能由流体挥发或者沸腾作用、冷凝作用、氧化还原反应、硫化物沉淀等引起。岩矿石中汞同位素的非质量分馏信息可能是地质历史时期汞光化学作用的产物,或者是继承某一特定的源岩信息所致。因此,未来汞同位素在示踪低温热液矿床的成矿物质来源、刻画成矿流体演化过程方面具有较大的应用潜力。  相似文献   

基于计算流体力学的寒区土壤水热耦合模型研究   总被引：1，自引：0，他引：1  

胡锦华  陆峥  仝金辉  李小雁  刘绍民  杨晓帆 《冰川冻土》2021,43(4):948-963

土壤水文过程（水分运移和传热）及其对气候变化的响应是寒区水文学的前沿问题。然而,冻土的存在使得寒区土壤水文过程变得极其复杂。此外,寒区自然环境恶劣,较难获取长时间序列和高分辨率的野外观测资料。近年来,充分利用已有的观测数据,构建寒区土壤水热耦合模型,并开展相应的数值模拟研究,已成为理解寒区土壤水文物理过程,揭示其动力学机制的重要途径。基于寒区土壤水文物理过程和计算流体力学方法,构建了高分辨率、适用于完全饱和状态下的寒区土壤水热耦合模型,且自主研发了相应的数值求解器和软件包。随后,通过一系列完全饱和状态下的验证算例,如经典的一维传热方程解析解、被广泛应用的二维基准测试算例和室内土柱冻结实验等,对已构建的模型进行了系统的检验。模型模拟结果与解析解、基准算例的结果以及实验数据相比,均有较好的一致性,表明该模型较为准确且高效地模拟了寒区土壤在完全饱和状态下的水分运移和传热过程,尤其能够精细刻画冻土水-冰相态变化等关键过程,有望成为研究寒区土壤水文过程的有力工具。  相似文献   

赣中聚源大型石英脉型白钨矿床含铀富钨矿物初步研究     

尹晓燕  李光来  刘晓东  苏晔  邬斌  韦星林  李成祥 《岩石学报》2021,37(5):1553-1566

聚源钨矿是华南地区为数不多的大型石英脉型白钨矿矿床之一。在详细的野外地质调查基础上,本文利用α径迹蚀刻、电子显微镜、扫描电镜以及电子探针等实验手段,对该矿床含钨和含铀矿物开展了精细矿物学的研究工作,探讨了成矿过程中钨和铀的富集规律。研究显示,该矿床钨铀矿物的形成可分为四个阶段:第一阶段,钨铀主要进入富含Nb、Ti的氧化物矿物,形成铌铁矿、钇易解石等富钨矿物,另有极少量的钨进入黑钨矿和早阶段白钨矿;第二阶段,铌铁矿与钇易解石被后期流体交代,形成含钨富铀的骑田岭矿、铌锰矿以及钛-钇易解石;第三阶段,钨进入中阶段白钨矿,这一阶段也是钨最主要的矿化阶段;第四阶段,钨进入晚阶段白钨矿。最后两阶段白钨矿中铀含量不高。骑田岭矿(WO_3 26.74%～29.68%),是聚源钨矿中除白钨矿和黑钨矿之外钨含量最高的含钨矿物。该矿易解石族矿物WO_3最高可达9.80%,极度富钨,是目前有文可查的钨含量最高的易解石。聚源钨矿中的含钨矿物大多数为白钨矿,但绝大多数的白钨矿却在骑田岭矿、易解石族矿物、铌铁矿族矿物、黑钨矿之后形成,说明成矿流体在演化过程中,绝大多数W首先进入富含Nb、Ti的含铀矿物和少量黑钨矿,之后才是白钨矿的大量结晶。  相似文献