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Direct numerical simulation of matrix diffusion across fracture/matrix interface

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water Science and Engineering 2013年第4期6卷 365-379页

作者： Yong ZHANG Eric M.LABOLLE Donald M.REEVES Charles RUSSELL division of Hydrologic Sciences Desert Research Institute Department of land Airand Water ResourcesUniversity of California

Accurate descriptions of matrix diffusion across the fracture/matrix interface are critical to assessing contaminant migration in fractured media. The classical transfer probability method is only applicable for relatively large diffusion coefficients and small fracture spacings, due to an intrinsic assumption of an equilibrium concentration profile in the matrix blocks. Motivated and required by practical applications, we propose a direct numerical simulation （DNS） approach without any empirical assumptions. A three-step Lagrangian algorithm was developed and validated to directly track the particle dynamics across the fracture/matrix interface, where particle＇s diffusive displacement across the discontinuity is controlled by an analytical, one-side reflection probability. Numerical experiments show that the DNS approach is especially efficient for small diffusion coefficients and large fracture spacings, alleviating limitations of the classical modeling approach.

关键词： Key words: fracture matrix interface direct numerical simulation transfer probability Lagrangian algorithm

Optimization of an Artificial Intelligence Database and Camera Installation for Recognition of Risky Passenger Behavior in Railway Vehicles

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Computers, Materials & Continua 2025年第1期82卷 1277-1293页

作者： Min-kyeong Kim Yeong Geol Lee Won-Hee Park Su-hwan Yun Tae-Soon Kwon Duckhee Lee Railroad Test&Certification division Korea Railroad Research Institute(KRRI)Cheoldo BangmulgwanroUiwang-si16105Republic of Korea Railroad Safety division Korea Railroad Research Institute(KRRI)Cheoldo BangmulgwanroUiwang-si16105Republic of Korea

Urban railways are vital means of public transportation in *** than 30%of metropolitan residents use the railways,and this proportion is expected to *** enhance safety,the government has mandated the installation of closed-circuit televisions in all carriages by ***,cameras still monitored *** address this limitation,we developed a dataset of risk factors and a smart detection system that enables an immediate response to any abnormal behavior and intensive monitoring *** created an innovative learning dataset that takes into account seven unique risk factors specific to Korean railway *** data collection was conducted across the Shinbundang Line of the Incheon Transportation Corporation,and the Ui-Shinseol *** observed several behavioral characteristics and assigned unique annotations to *** also considered carriage *** performance was evaluated by camera placement and *** the camera installation plan was *** dataset will find immediate applications in domestic railway *** artificial intelligence algorithms will be verified shortly.

关键词： AI railway vehicle risk factor smart detection AI training data

THREE DIMENSIONAL NUMERICAL MODELLING OF FLOW AND SEDIMENT TRANSPORT IN RIVERS

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International Journal of Sediment Research 2007年第3期22卷 188-198页

作者： M. A. MEKONNEN B. DARGAHI Research candidate KTH Land & Water Resource Engrg. Division of Hydraulic Engrg Stockholm Associate Professor KTH Land & Water Resource Engrg. Division of Hydraulic Engrg. Stockholm

The 3D numerical model, ECOMSED (open source code), was used to simulate flow and sediment transport in rivers. The model has a long history of successful applications to oceanic, coastal and estuarine waters. Improvements in the advection scheme, treatment of river roughness parameterization and shear stress partitioning were necessary to reproduce realistic and comparable results in a river application. To account for the dynamics of the mobile bed boundary, a model for the bed load transport was included in the code. The model reproduced observed secondary currents, bed shear stress distribution and erosion-deposition patterns on a curved channel. The model also successfully predicted the general flow patterns and sediment transport characteristics of a 1-km long reach of the River Klar?lven, located in the north of the county of V?rmland, Sweden.

关键词： Roughness parameterization Numerical models River flow Sediment transport

Global black soil distribution

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Frontiers of Agricultural Science and Engineering 2024年第2期11卷 271-281页

作者： Yuxin TONG Marcos E.ANGELINI Yusuf YIGINI Isabel LUOTTO Global Soil Partnership Land and Water DivisionFood and Agriculture Organization of the United NationsRome 00153Italy

Black soils, characterized by their thick, dark horizons enriched with organic matter, epitomize highly fertile soils. However, their fertility precipitates intense land use, engendering challenges such as soil erosion, nutrient depletion, pollution, compaction, salinization, and acidification. Notably, these soils are significant contributors to global greenhouse gas emissions, primarily due to substantial losses in soil organic carbon. Despite these challenges, black soils are pivotal for global food production. This paper delineates the implementation of digital soil mapping for the global cartography of black soils and human interference on these soils. Predominantly distributed in Eastern Europe, Central and Eastern Asia, and North and South America, black soils cover an approximate area of 725 Mha, with the Russian Federation,Kazakhstan, and China collectively have over half of this area. Agriculturally,these soils underpin significant proportions of global crop yields, producing 66% of sunflower, 30% of wheat, and 26% of potato outputs. The organic carbon content in the upper 30 cm of these soils is estimated at 56 *** management of black soils is imperative for ensuring food security and addressing climate change on a global scale.

关键词： Black soils distribution map food security soil organic carbon

Preliminary Insights into the Habitat Preferences of the Centralian Bandy Bandy (Vermicella vermiformis)(Squamata: Elapidae) in Central Australia

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Asian Herpetological Research 2014年第1期5卷 49-53页

作者： Peter J.MCDONALD Gary W.LUCK Flora and Fauna division Department of Land Resource Management Northern Territory Government School of Environmental Sciences Charles Sturt University Institude for land Water and Society Charles Sturt University

Bandy Bandy’s（Vermicella spp.）are a striking,black-and-white ringed genus of small elapid snakes endemic to *** taxa are burrowers and little is known of their biology and *** investigated the habitat preferences of the only arid-dwelling species,the centralian bandy bandy（Vermicella vermiformis）,in the MacDonnell Ranges west of Alice Springs in the Northern *** systematic road-cruising,we encountered *** over a 12 months period between 2009 and *** used logistic regression to model the occurrence of the species against a range of different habitat variables collected at multiple *** the small sample size,*** exhibited a clear preference for acacia shrubland habitats,with acacia variables present in all AICc ranked models in the 95%confidence *** factors driving this association,together with the preference for habitat not burnt in the most recent wildfires,may be related to the abundance of their only known prey,blind snakes（Ramphotyphlops spp.）.

关键词： Snake Arid Acacia Fire Ramphotyphlops

Uncertainty of soil erosion modelling using open source high resolution and aggregated DEMs

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Geoscience Frontiers 2017年第3期8卷 425-436页

作者： Arun Mondal Deepak Khare Sananda Kundu Sandip Mukherjee Anirban Mukhopadhyay Surajit Mondal Department of water Resources Development & Management Indian Institute of Technology Roorkee India Department of Natural Resources TERI University New Delhi 110 070 India School of Oceanographic Studies Jadavpur University Kolkata India d Division of Land division of land & water Management Research Complex for Eastern Region(RCER)Indian Council of Agricultural Research(ICAR) Patna India

Digital Elevation Model （DEM） is one of the important parameters for soil erosion assessment. Notable uncertainties are observed in this study while using three high resolution open source DEMs. The Revised Universal Soil Loss Equation （RUSLE） model has been applied to analysis the assessment of soil erosion uncertainty using open source DEMs （SRTM, ASTER and CARTOSAT） and their increasing grid space （pixel size） from the actual. The study area is a part of the Narmada river basin in Madhya Pradesh state, which is located in the central part of India and the area covered 20,558 km2. The actual resolution of DEMs is 30 m and their increasing grid spaces are taken as 90, 150, 210, 270 and 330 m for this study. Vertical accuracy of DEMs has been assessed using actual heights of the sample points that have been taken considering planimetric survey based map （toposheet）. Elevations of DEMs are converted to the same vertical datum from WGS 84 to MSL （Mean Sea Level）, before the accuracy assessment and modelling. Results indicate that the accuracy of the SRTM DEM with the RMSE of 13.31, 14.51, and 18.19 m in 30, 150 and 330 m resolution respectively, is better than the ASTER and the CARTOSAT DEMs. When the grid space of the DEMs increases, the accuracy of the elevation and calculated soil erosion decreases. This study presents a potential uncertainty introduced by open source high resolution DEMs in the accuracy of the soil erosion assessment models. The research provides an analysis of errors in selecting DEMs using the original and increased grid space for soil erosion modelling.

关键词： DEM RUSLE SRTM ASTER CARTOSAT

Climatic regionalization mapping of the Murrumbidgee Irrigation Area,Australia

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Progress in Natural Science:Materials International 2009年第12期19卷 1773-1779页

作者： Shahbaz Khan Akhtar Abbas Tariq Rana Sustainable water Resources Development and Management Section Division of Water SciencesUNESCOIrue Miollis 75015 ParisFrance CSIRO land and water University CanberraACTAustralia Murray Darling Basin Authority CanberraACTAustralia

In this study,spatial analysis techniques were used to generate climatic zoning maps of the East Murrumbidgee Irrigation Area(MIA), *** term climate data were used to analyze and assess regional climatic variation by cluster analysis in a GIS environment. Based on thermal and moisture factors,four variables were chosen to develop climate *** variables include annual average rainfalls, annual average ETc,annual average Growing Day Degree(GDD) and daily average temperature generated from daily climate data of 36 years(1971-2006) on 12 local weather stations as the fundamental elements of regional climate ***-based spatial analysis models are used to map climate sub-regions from sets of climatic parameters derived from regional climate data *** climate zoning schemes are presented by integration of spatial interpolation,spatial cluster analysis and climate indices *** scheme comes with the two climate zones of the West and the East based on spatial cluster analysis according to selected climatic variables, and the other comes with the three comprehensive hydro-thermal zones and the six hydro-thermal balance zones.

关键词： Agro-climatic regionalization Regional climatic variation Climatic zone mapping Murrumbidgee Irrigation Area GIS

全球重要农业文化遗产:一个有助于提高农业、生态与传统社会可持续性的综合观点

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资源科学 2009年第6期31卷 905-913页

作者： Mary Jane Dela Cruz Parviz Koohafkan land and water division FAO Rome Italy

20世纪90年代以来,可持续发展理念在全球取得了广泛共识并延伸到农业生产系统,根据可持续发展战略和环境议程的需要,各个国家均已构建了许多自然资源可持续管理的途径并付诸实施,支持了乡村社区的发展并提高了他们的生计水平。本文简要... 详细信息

20世纪90年代以来,可持续发展理念在全球取得了广泛共识并延伸到农业生产系统,根据可持续发展战略和环境议程的需要,各个国家均已构建了许多自然资源可持续管理的途径并付诸实施,支持了乡村社区的发展并提高了他们的生计水平。本文简要概括了一种自然资源可持续管理的途径及其背景和特点。这种综合管理途径,如全球重要农业文化遗产的动态保护以及与其相关的农业和生态知识系统,至今仍然对传统社会、应对全球气候变化和维持生计有着重要的影响,值得进一步重新审视。 2002年,联合国粮农组织发起的重要活动之一就是全球重要农业文化遗产(GIAHS)的保护与适应性管理,该项目旨在对全球重要的、受到威胁的传统农业文化遗产系统进行保护。全球重要农业文化遗产是指:"农村与其所处环境长期协同进化和动态适应下所形成的独特的土地利用系统和农业景观,这些系统与景观具有丰富的生物多样性,而且可以满足当地社会经济与文化发展的需要,有利于促进区域可持续发展",是在当地资源条件、不断发展变化的知识体系与经过长期验证的丰富经验的基础上,反映了人类与文化多样性的协同发展,揭示了人与自然和谐共生的深刻关系。这些生动鲜活且不断演变进化的系统和社区,一直保持着与诸如自然、家庭、社区、历史以及对其自然环境的归属感等融为一体所具有的特性。全球重要农业文化遗产的动态保护,是综合管理途径的一个具体实例,是一个将农业、生态与传统社会可持续性融合在一起的综合观点。这项计划正在全球范围实施,以促进对全球重要农业文化遗产的认识并保障其继续协同发展。该项目所推动的动态保护途径将:1)在国际和国家层面上,进一步推动公众对全球重要农业文化遗产内在价值的认识;2)在试点国家制定部门内部及部门间的计划和政策时,将GIAHS中的全球重要农业生物多样性的保护和适应性管理作为主要内容;3)通过采用考虑到生态与文化相互作用的新技术,促进当地社区社会政策与经济的发展;)通过实践和经验交流,进一步推广和扩大GIAHS的保护。

关键词：全球重要农业文化遗产农业与生态知识传统社会动态保护

Conserving Agricultural Heritage Systems through Tourism: Exploration of Two Mountainous Communities in China

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Journal of Mountain Science 2013年第6期10卷 962-975页

作者： SUN Ye-hong Mary Jane DELA CRUZ MIN Qing-wen LIU Mou-cheng ZHANG Ling-yun Institute of Tourism Beijing Union University land and water division Natural Resources and Environment Management Department Food and Agriculture Organization Institute of Geographic Sciences and Natural Resources research Chinese Academy of Sciences

Community plays an important role in the preservation of agricultural heritage system （AHS）. Recently, many AHS have been valorized as interesting resources for rural tourism. The expectations are that tourism development （TD） can be supportive for the conservation of AHS while creating benefits for local communities. In this study, two mountainous pilot villages （Longxian and Xiaohuang） in a global conservation project for traditional agricutural systems - Globally Important Agricultural Heritage Systems （GIAHS） were selected to identify the relationship between AHS conservation and TD. The study undertook in-depth interviews, and questionnaires of village residents and informal discussions with local villagers. A t-test and a linear regression model were implemented to explore the comparative dimensions of the two communities with different geographical location, economic situation, and stage of TD. The research found some similarities and differences in the two mountainous communities during AHS conservation and TD. Firstly, AHS are preservaed well in both villages unconsiously, while the residents in Xiaohuang value more highly the heritage elements than the respondents in Longxian, and the villagers in Xiaohuang are more worried about their heritage system; Secondly, both villages expect lots of benefits from TD and they clearly perceive more positive than negative impact from tourism and thus approve TD, while the hugedifferent perception on transportation and accessibility in the two villages reflects the bottleneck of TD in Xiaohuang village. At the same time, the respondents from Xiaohuang perceive more positive and fewer negative impact from tourism than the respondents from Longxian. Thirdly, the respondents in the two villages all show positive attitudes towards participation in tourism mostly motivated by the high income expectation. The main factors to determine the community perception in two villages were also analyzed based on the data process. A lo

关键词： Agricultural heritage system Tourismdevelopment Mountainous communities ZhejiangProvince Guizhou Province China