Communication,Partnerships, and the Role of Social Science: Conservation Delivery in a Brave New World     

Aritree Samanta  Francis R. Eanes  Benjamin Wickerham  Mary Fales  Brian R. Bulla  Linda S. Prokopy 《社会与自然资源》2020,33(7):914-926

Abstract

The Saginaw Bay Regional Conservation Partnership Program (RCPP) in Michigan is an innovative conservation effort organized to address water quality impairments involving a unique collaboration between conservation organizations, agronomists, universities, commodity groups, and agribusinesses. We track the evolution and adaptation of the Saginaw Bay RCPP, and the collaboration among the traditional and nontraditional conservation partners. Our reflections are organized around three key lessons: vertical and horizontal communication challenges; contextual and structural constraints; barriers that remain between private and public sector entities for this and alternative conservation-delivery models. Lessons from this evaluation will inform the design of future collaborative/multi-stakeholder watershed management efforts. We also demonstrate that rather than being used as an ad-hoc approach, social science evaluation was integrated into conservation planning and practice, hence increasing the salience and legitimacy of the conservation social science in collaborative watershed management.  相似文献   

Numerical modeling of hydraulic fracture propagation,closure and reopening using XFEM with application to in‐situ stress estimation          下载免费PDF全文

T. Mohammadnejad  J.E. Andrade 《国际地质力学数值与分析法杂志》2016,40(15):2033-2060

In this paper, a fully coupled model is developed for numerical modeling of hydraulic fracturing in partially saturated weak porous formations using the extended finite element method, which provides an effective means to simulate the coupled hydro‐mechanical processes occurring during hydraulic fracturing. The developed model is for short fractures where plane strain assumptions are valid. The propagation of the hydraulic fracture is governed by the cohesive crack model, which accounts for crack closure and reopening. The developed model allows for fluid flow within the open part of the crack and crack face contact resulting from fracture closure. To prevent the unphysical crack face interpenetration during the closing mode, the crack face contact or self‐contact condition is enforced using the penalty method. Along the open part of the crack, the leakage flux through the crack faces is obtained directly as a part of the solution without introducing any simplifying assumption. If the crack undergoes the closing mode, zero leakage flux condition is imposed along the contact zone. An application of the developed model is shown in numerical modeling of pump‐in/shut‐in test. It is illustrated that the developed model is able to capture the salient features bottomhole pressure/time records exhibit and can extract the confining stress perpendicular to the direction of the hydraulic fracture propagation from the fracture closure pressure. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

A review of classical dimensionless numbers for the Yusa problem based on discriminated non‐dimensionalization of the governing equations          下载免费PDF全文

M. Cánovas  I. Alhama  E. Trigueros  F. Alhama 《水文研究》2016,30(22):4101-4112

When the governing equations of a problem are known, the non‐dimensionalization of these equations (applied in their classical form) is a useful and widely used method that can be used to identify the dimensionless groups that rule the solution. However, neither this technique nor dimensional analysis necessarily provides the most precise solution in terms of the sought numbers. The use of discrimination, a qualitative rather than quantitative extension of the non‐dimensionalization method, has demonstrated notable advantages over the classical method because it invariably provides a more precise set of dimensionless groups. The basis for the correct application of discrimination depends on a deep understanding of the phenomena involved in the problem, particularly in complex (coupled) problems. In this paper, discriminated non‐dimensionalization is applied to investigate a mixed convection problem in porous media, the Yusa problem. The derived discriminate groups are compared with those already known in the literature and deduced by classical methods. A number of scenarios are numerically solved to check the reliability of the discriminated groups in contrast with classical groups. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

An elasto‐plastic three phase model for partially saturated soil for the finite element simulation of compressed air support in tunnelling     

F. Nagel  G. Meschke 《国际地质力学数值与分析法杂志》2010,34(6):605-625

This paper presents a fully coupled finite element formulation for partially saturated soil as a triphasic porous material, which has been developed for the simulation of shield tunnelling with heading face support using compressed air. While for many numerical simulations in geotechnics use of a two‐phase soil model is sufficient, the simulation of compressed air support demands the use of a three‐phase model with the consideration of air as a separate phase. A multiphase model for soft soils is developed, in which the individual constituents of the soil—the soil skeleton, the fluid and the gaseous phase—and their interactions are considered. The triphasic model is formulated within the framework of the theory of porous media, based upon balance equations and constitutive relations for the soil constituents and their mixture. An elasto‐plastic, cam–clay type model is extended to partially saturated soil conditions by incorporating capillary pressure according to the Barcelona basic model. The hydraulic properties of the soil are described via DARCY 's law and the soil–water characteristic curve after VAN GENUCHTEN . Water is modelled as an incompressible and air as a compressible phase. The model is validated by means of selected benchmark problems. The applicability of the model to geotechnical problems is demonstrated by results from the simulation of a compressed air intervention in shield tunnelling. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

虚拟地理环境下的地理空间认知初步探索     

刘浩  薛梅 《遥感学报》2021,25(10):2027-2039

地理空间认知是人类获取地理空间知识、认知地理环境的重要方法和手段,虚拟地理环境VGEs（Virtual Geographic Environments）作为继地图和地理信息系统（GIS）之后的新一代地理分析工具,在地理空间认知方面具有显著优势,但目前相关研究尚处于概念探讨和框架搭建阶段,缺乏对地理空间认知内涵及相关技术方法的论述和研究。本文以经典的地理学6问题求解为导向,从地理本体认知、地理过程认知和地理行为认知3个层次,阐述了VGEs地理空间认知的内涵和基本内容;进一步重点探讨了实现VGEs地理空间认知的相关技术方法,包括城市空间表达与城市计算、多模式人机交互、地理知识图谱与空间推理、地理过程模拟、地理行为模式识别与情感计算等方面。以重庆为例开展了应用案例实践,展示了如何利用相关技术方法实现对地理环境和地理空间对象的认知和理解。本文提出的总体框架和技术体系为VGEs地理空间认知的深入开展和技术实现提供了新的思路和解决方案,有助于将该项工作从理论探讨阶段推向技术实现阶段。  相似文献   

基于5G技术的实时三角测绘在测绘信息中的应用     

林建涛  陈曼曼  周新星 《测绘与空间地理信息》2021,44(4):101-105

本研究基于5G技术的实时三角测绘在测绘信息中的应用案例。通过瀑布式开发模型,本文在明确使用三角控制测量法的前提下,使用5G技术及其带来的分布式计算技术和自适应组网技术,对基于5G技术的实时沉降三角测绘系统进行了开发,通过组网测试,发现该系统的测量精度与使用全站仪人工测量精度相当,且系统部署过程并未对原有的IDC核心节点增加任何设备,系统稳定性、可靠性良好,与原有IDC设施的兼容性良好。所以,本文认为,5G技术在沉降控制测量任务中具有极大的技术优势。  相似文献   

基于云计算的新型高鲜度电子地图平台构建     

陈小雨  张璐  陈会仙  付宇  孙永烈 《测绘通报》2021,(11):151-154

在电子科技发展迅猛的新时代,电子地图可为车载导航、手机、PAD、互联网等使用者提供基于位置的各种服务。针对现有电子地图生产平台更新频率低、处理速度慢、现势性差等问题,本文利用大数据挖掘、云计算及人工智能等新技术,通过自动识别成图及自动化编辑能力,对电子地图的在线快速更新技术,以及从采集、编辑到出品的一体化流程进行了研究。并以此建立了基于云计算的新型高鲜度电子地图平台,实现了电子地图道路信息与兴趣点的在线增量更新,大幅度提升了电子地图的生产能力、准确率及效率。  相似文献   

矿山遥感编图中的高分辨率遥感数据选择与比例尺计算方法   总被引：2，自引：1，他引：1  

何芳  李林  徐友宁  柯海玲  张江华  乔冈  刘瑞平  陈华清 《地质通报》2015,34(11):2037-2046

通过对青海调查矿区多种高分辨率卫星数据处理后形成的图像进行解译和编图,掌握了合理选择遥感数据信息源、利用制图软件计算遥感影像图比例尺及编制野外调查和成果解译图的技术方法。得出在选择遥感数据时要考虑不同数据的技术参数、性价比及调查区面积;明确了当图像的出图分辨率确定后,其比例尺与图像的空间分辨率、像素大小、文档大小有直接关系,同时建立了计算遥感图像最佳比例尺和最佳出图比例尺的公式和方法;介绍了利用Photoshop和Mapgis软件,编制矿山野外调查用图和遥感解译成果图件的流程及方法。这些工作的完成对青海矿业开发地质环境效应调查起到了积极的指导作用,也充分体现了高分辨率遥感图像在工作条件艰苦地区的优势作用。  相似文献   

网络舆情态势及情感多维特征分析与可视化——以COVID-19疫情为例     

杜毅贤  徐家鹏  钟琳颖  侯盈旭  沈婕 《地球信息科学学报》2021,23(2):318-330

2020年初,新型冠状病毒肺炎（COVID-19）疫情席卷全国,疫情发展变化引发了社会各界的广泛关注。社交媒体平台作为网络舆情的重要载体,如何从中全面、准确挖掘分析网络舆情特征是疫情防控过程中的重要问题。本研究首先从舆情本体与客体时空关联的角度构建了疫情期间网络舆情多维分析模型,获取了2020年1月17日—3月17日多个媒体平台中新冠肺炎疫情相关的网络舆情数据;其次以疫情蔓延的视角,运用比较研究法、Spearman相关系数等方法探索了武汉市、湖北省及全国尺度下的网络舆情态势时空演变及语义特征;最后使用HowNet情感词典和情感词汇本体进行了舆情情感分析,并使用可交互信息图表对其进行可视化。结果表明：① 武汉市、湖北省、全国尺度下的每日舆情数据数量与每日新增病例数之间存在正相关关系;② 舆情数据数量的空间分布与疫情分布存在正相关关系,舆情数据数量多的地区多为疫情较为严重的地区; ③ 研究时段内不同媒体平台的舆情中立情感最多,新闻平台与论坛、微信、微博相比,整体情绪更为正面;④ 在疫情发展的不同阶段,微博热搜数据情感特征有较大差异,总体上呈现正面情绪多于负面。研究表明,基于本文提出的多维分析模型可以直观展现疫情期间多尺度下的舆情态势、舆情焦点和情绪变化,从而为政府及相关部门有效引导与控制网络舆情提供理论基础支撑和参考借鉴。  相似文献   

基于百度迁徙数据的中国城市网络结构特征研究     

张小东  韩昊英  唐拥军  罗国娜 《地球信息科学学报》2021,23(10):1798-1808

迁徙流作为互联网时代的新产物,信息流、资本流、交通流等流空间的基本载体,能客观地反映城市间地理行为关系,对于刻画城市网络结构具有重要意义。基于地级以上城市的百度迁徙大数据,本文尝试从全域和净迁徙的视角探索研究中国城市网络结构特征,对其网络的层级、关联关系和影响因素等进行挖掘提取。研究发现：① 全国城市网络呈现出稳定的、层级明确的三棱锥四顶点“钻石型”结构,与主要城市群的经济规模空间分布相吻合;② 区域网络表现出向高级别行政中心集聚的“核心—外围”放射状结构;③ 以省会城市为核心的典型小世界特征比较凸出,小世界网络的可达性和连通性较高;周口、阜阳、赣州、上饶、重庆等作为主要劳动力输出型城市,深圳、东莞、广州、北京、上海等城市成为了主要的外来人口聚集地,并形成了对应的人口就近输送网络关系;④ 城市的行政地位、经济规模、交通枢纽建设、劳动力资源等因素都对其网络控制力和影响力起到了决定性作用。最后,研究结合中国城市网络结构特征及其主要影响因素,提出相关政策建议,以期为中国城市网络结构均衡发展与建设提供借鉴依据。  相似文献