内蒙古生态承载力评价及生态安全格局优化   总被引：2，自引：0，他引：2  

冯琰玮  甄江红  马晨阳 《地理研究》2021,40(4):1096-1110

生态安全水平对区域发展的约束作用不断增强,构建科学合理的生态安全格局可以有效缓解经济发展与环境保护之间的矛盾.以内蒙古自治区为研究区,2000年、2005年、2010年、2015年为间断点,建立区域生态承载力评价指标体系,探讨生态承载力时空演变特征;甄别生态优势斑块,结合自然保护区等重要生态斑块组建生态源地,建立生态源...  相似文献   

基于路网数据和复杂图论的中国城市交通布局评价     

寇世浩  姚尧  郑泓  周剑锋  张嘉琪  任书良  王瑞凡  关庆锋 《地球信息科学学报》2021,23(5):812-824

城市化的快速发展推动了我国城市道路网的不断扩张和发展.城市道路网是一个动态、开放、自组织的空间复杂网络,构成了城市的结构框架,研究城市道路网的结构特征对路网规划和城市建设有着重要的应用价值.在国内城市道路网络结构特征的相关研究中,很少有学者基于道路走向的视角对整个城市路网结构进行研究,也缺少对全国主要城市路网的整体性评...  相似文献   

Census survey approach to quantifying īnanga spawning habitat for conservation and management     

Shane Orchard  Michael J. Hickford 《新西兰海洋与淡水研究杂志》2018,52(2):284-294

Here, we describe a methodology for quantifying the spawning habitat of īnanga (Galaxias maculatus), a protected native fish species. Our approach is demonstrated with a survey of the Heathcote/ōpāwaho following the Canterbury earthquakes that produced unexpected findings. Spawning habitat was detected over a 2.5?km reach and the area occupied by spawning sites (75m²) was much larger than in previous records (ca.?21m²). Sites dominated by the invasive Phalaris arundinaceae were found to support high egg numbers. Spawning has not previously been recorded on this species and it is identified in the literature as a threat to spawning habitat. Considerable spatio-temporal variation was also detected in the location of spawning sites and pattern of egg production. Together, these aspects illustrate the need for a comprehensive survey methodology to reliably quantify spawning habitat. The Heathcote/ōpāwaho example shows the utility of our census approach for achieving this, and supporting habitat conservation objectives.  相似文献   

基于分布式控制力矩陀螺的水下航行器轨迹跟踪控制   总被引：2，自引：0，他引：2  

黄道敏  徐瑞昆  唐国元  冯雷  刘智  徐国华 《海洋工程》2018,36(6):69-76

基于控制力矩陀螺群(CMGs)的水下航行器具有低速或零速机动的能力。采用基于分布式CMGs的水下航行器方案,并研究其水平面的轨迹跟踪控制问题。通过全局微分同胚变换将非完全对称的动力学模型解耦成标准欠驱动控制模型,并根据简化的模型构建其轨迹跟踪的误差动力学模型,将轨迹跟踪控制问题转化为误差模型镇定问题。基于一种分流神经元模型和反步法设计了系统的轨迹跟踪控制律,该控制器不需要对任何虚拟控制输入进行求导计算,且能确保跟踪误差的最终一致有界性。仿真结果表明该控制器能够实现在不依赖动力学参数先验知识的情况下对光滑轨迹的有效跟踪。  相似文献   

Guiding ecological principles for marine spatial planning     

Melissa M. Foley  Benjamin S. Halpern  Fiorenza Micheli  Matthew H. Armsby  Margaret R. Caldwell  Caitlin M. Crain  Erin Prahler  Nicole Rohr  Deborah Sivas  Michael W. Beck  Mark H. Carr  Larry B. Crowder  J. Emmett Duffy  Sally D. Hacker  Karen L. McLeod  Stephen R. Palumbi  Charles H. Peterson  Helen M. Regan  Mary H. Ruckelshaus  Paul A. Sandifer  Robert S. Steneck 《Marine Policy》2010

The declining health of marine ecosystems around the world is evidence that current piecemeal governance is inadequate to successfully support healthy coastal and ocean ecosystems and sustain human uses of the ocean. One proposed solution to this problem is ecosystem-based marine spatial planning (MSP), which is a process that informs the spatial distribution of activities in the ocean so that existing and emerging uses can be maintained, use conflicts reduced, and ecosystem health and services protected and sustained for future generations. Because a key goal of ecosystem-based MSP is to maintain the delivery of ecosystem services that humans want and need, it must be based on ecological principles that articulate the scientifically recognized attributes of healthy, functioning ecosystems. These principles should be incorporated into a decision-making framework with clearly defined targets for these ecological attributes. This paper identifies ecological principles for MSP based on a synthesis of previously suggested and/or operationalized principles, along with recommendations generated by a group of twenty ecologists and marine scientists with diverse backgrounds and perspectives on MSP. The proposed four main ecological principles to guide MSP—maintaining or restoring: native species diversity, habitat diversity and heterogeneity, key species, and connectivity—and two additional guidelines, the need to account for context and uncertainty, must be explicitly taken into account in the planning process. When applied in concert with social, economic, and governance principles, these ecological principles can inform the designation and siting of ocean uses and the management of activities in the ocean to maintain or restore healthy ecosystems, allow delivery of marine ecosystem services, and ensure sustainable economic and social benefits.  相似文献   

乡镇规划制图的探讨     

刘艳芳 《武汉大学学报(信息科学版)》1988,(1)

本文对地图制图如何为城乡规划与建设服务进行了初步探讨。重点放在乡镇规划图的选题上,应从点和面两个不同方面进行考虑。  相似文献   

A comprehensive approach to drought and desertification in Northern Nigeria     

E. O. Oladipo 《Natural Hazards》1993,8(3):235-261

Drought has been a recurring feature of the arid and semi-arid areas of Nigeria. This paper reviews the extent, severity, and consequences of drought and desertification in Nigeria with particular emphasis on the northern part of the country. The haphazard manner in which these environmental hazards have been tackled is examined and a systematic approach for the formulation of a national policy is proposed. It is recommended that a detailed formulation and implementation of the proposed policy plan is imperative to mitigate the often devastating impacts of drought and desertification in the very prone areas of Nigeria. Until such is done, some areas of Nigeria will always be vulnerable to the whims of an inevitable climatic hazard of drought and associated land degradation in the form of desertification.  相似文献   

中国水质站网规划中几个问题的探讨          下载免费PDF全文

赵海瑞  秦福兴 《水科学进展》1993,4(1):63-68

在完成中国水质站网规划工作的基础上,对下列问题作了进一步探讨:(1)水质站网规划单元的划分;(2)聚类分析在水质站网规划中的应用;(3)站网密度与人口和经济发展的关系;(4)中国水质站网的分区特征。  相似文献   

地理信息系统支持区域土地利用决策的研究   总被引：31，自引：1，他引：31  

黄杏元  倪绍祥 《地理学报》1993,48(2):114-121

本文以江苏省溧阳县为例,研究地理信息系统技术在区域土地利用多目标规划中的应用,着重探讨地理信息系统支持的区域土地利用决策原理和方法。研究表明,在地理信息系统的支持下,通过单项适宜性评价模型和生产布局决策模型的建立与运行,可以有效地进行研究区合理的土地利用布局和为区域土地管理提供依据。  相似文献   

对我国国土规划几个主要问题的重新认识   总被引：4，自引：2，他引：4  

凡杰 《地理研究》1993,12(1):56-63

本文基于对我国国土规划近十年实践中所反映的问题的分析,阐述了应改变国土规划的基本性质、以空间结构布局为其核心内容,以及国土规划一般不宜在市域或地区及以下地域层次开展的观点,进而就国土规划特性新的内涵、国土规划的内容重点等问题进行了初步探讨。  相似文献