首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.
在城市景观规划与城市生态环境演变研究中,理解与把握城市景观格局信息至关重要.本文以海淀区2006年ALOS卫星为研究数据,运用面向对象的影像分类方法获取景观类型分布,选取景观分维数、破碎度、分离度等景观指数来定量描述海淀区的景观格局.研究表明海淀区景观多样性指数较低,景观类型面积所占比例差异大,人为作用影响显著.居民地及工矿用地景观和耕地景观构成海淀区的景观基质,道路交通景观构成廊道景观,林地景观相对较稳定,而水域景观和草地景观受人为干扰严重,需要加强管理与规划.  相似文献   

2.
为了解江苏省近35 a来的景观格局变化特征,以1980~2015年7期土地利用数据为基础,对江苏省各景观格局指数、景观稳定性及其与人为干扰度的关系进行分析,结果表明:(1)从类型上看,江苏省建设用地的破碎化程度最高且形状最不规则,但随时间趋于完整、规则;耕地和水域的斑块聚集程度和紧凑度高,但呈逐渐降低的趋势。(2)从整体上看,江苏省整体的景观类型复杂程度增大,空间连通性逐渐降低,景观多样性和异质性增加;各景观类型面积趋于均匀化,但优势景观类型对整个景观的控制作用仍然较强。(3)江苏省1980~2015年大部分区域景观稳定性较低,人为干扰度较高,且不同时期之间的变化较小。(4)人为干扰度与斑块密度、景观分离度、香农多样性指数、香农均匀度指数、景观稳定性在15 km×15 km尺度相关性最高,与总边缘对比度指数、蔓延度指数在2 km×2 km尺度达到最高的相关性。该研究成果为解决建设用地的供需问题、优化土地利用结构、保护生态环境等提供科学依据。  相似文献   

3.
以位于黄河下游沿岸的河南省封丘县为研究区域,通过遥感影像解译、地理信息系统和景观格局计算软件,分析了该区域1990、2000年土地利用和景观格局的变化特征,运用典型相关分析方法,找出土地利用和景观格局变化的驱动因子,结果如下:研究期间居民点与建设用地增加2934.87 hm2,其它类型用地减少,尤其是旱地、水体分别减少1084.81 hm2、1717.92 hm2;以种植业用地为基质(旱地、水田用地比例之和近80%)的农业景观较为稳定,但农业结构单一、景观多样性较低;人口数量、粮食生产、对优越生活条件的追求等农业社会经济条件的变化是研究区土地利用与景观格局演变的驱动因子.  相似文献   

4.
以位于黄河下游沿岸的河南省封丘县为研究区域,通过遥感影像解译、地理信息系统和景观格局计算软件,分析了该区域1990、2000年土地利用和景观格局的变化特征,运用典型相关分析方法,找出土地利用和景观格局变化的驱动因子,结果如下:研究期间居民点与建设用地增加2 934.87 hm2,其它类型用地减少,尤其是旱地、水体分别减少1 084.81 hm2、1 717.92 hm2;以种植业用地为基质(旱地、水田用地比例之和近80%)的农业景观较为稳定,但农业结构单一、景观多样性较低;人口数量、粮食生产、对优越生活条件的追求等农业社会经济条件的变化是研究区土地利用与景观格局演变的驱动因子。  相似文献   

5.
选择深圳市作为研究对象,利用2006年的遥感影像,研究了深圳市景观空间格局的梯度变化特征。结果表明:景观多样性指数沿梯度区呈先增大后减少的趋势。在城区内其值较低,在城乡结合区域因类型斑块交错分布其值较高;在城区景观斑块密度与边缘密度较小,景观异质性较低。越靠近城乡结合处景观异质程度越大。从景观平均形状指数和景观平均分维数的变化,可看出人为活动的干扰由市中心向郊区发展是呈增强的趋势。以上分析表明景观格局的空间分布与受人为干扰程度有重要的联系。  相似文献   

6.
研究土地利用景观格局的地形分异特征及其驱动机制,对于土地利用优化及景观动态管理具有重要意义。选择地形复杂、覆被类型多样、以旅游干扰为主的张家界市永定区为研究对象,将研究区多个年份的景观类型图与高程、坡度、坡向分级图逐个叠加并进行分类统计;从景观水平指数和类型水平指数中选取斑块密度(PD)、聚合度指数(AI)、蔓延度指数(CONTAG)等8个景观指数,计算指数年份变化,探讨其地形分异规律和驱动机制。结果表明:(1)研究区土地利用景观类型具有明显的海拔梯度特征,80%以上的土地面积集中于海拔300~800 m与坡度6°~35°的区域;(2)无论是景观水平指数还是类型水平指数,其地形分异特征明显,且高程与坡度的分异明显高于坡向分异;(3)地形梯度较大区域(高海拔陡坡区)的土地利用景观格局演变以自然生态演变导向为主,而地形梯度较小区域(低海拔缓坡区域)的演变受社会经济因子干扰较明显。  相似文献   

7.
选取乌苏里江中下游干流50km缓冲区为研究区,以1989、2000和2013年的Landsat TM、OLI遥感影像为数据源,利用面向对象的分类方法获取湿地信息;在GIS技术支持下,选取斑块类别面积(CA)、面积所占比例(PLAND)、最大斑块面积指数(LPI)、平均斑块面积(AREA-MN)、斑块数(NP)、斑块密度(PD)等景观格局指数,分析了研究区1989~2013年湿地的景观格局动态特征。结果表明:面向对象的分类方法能够准确提取湿地信息,并且有效地避免"椒盐现象";1989~2013年,该区水田、水库/坑塘、运河/水渠、灌丛沼泽增加和河流、湖泊、草本沼泽、森林沼泽减少;大量草本沼泽转为水田为该区湿地变化主要特征;1989年湿地类型以草本沼泽为主,2013年水田的斑块面积略高于草本沼泽斑块面积;湿地景观变化区主要分布于中国一侧的挠力河流域和穆棱河流域;天然湿地景观破碎化程度逐年加深,人工湿地景观趋于聚集,人为干扰是导致湿地景观格局变化的主要动力;中俄两国境内湿地景观变化程度差异显著,中国境内大量天然湿地转为人工湿地;俄罗斯境内的湿地变化微小,天然湿地保存较好。农田垦殖是导致两国湿地景观破碎程度差异的主要原因。  相似文献   

8.
为有效过滤常规山顶点提取方法中的伪点,并探讨不同地貌区山顶点空间分布格局的差异特征,设计了由数字高程模型(DEM)导出等高线的山顶点提取方法。研究以ASTER GDEM为数据源,遴选秦岭中高山区、大巴中山区、低山丘陵区和黄土梁区作为典型地貌样区,采用封闭等高线套合法提取区域山顶点,采用最邻近指数及点间平面距离分析关联格局特征。研究结果表明:秦岭中高山区山顶点最邻近指数为0.76,聚集程度最高;低山丘陵区和大巴中山区分别为0.80、0.82,呈相对聚集;黄土梁区为1.01,接近随机分布,与现实地貌特征相符。研究探索了基于封闭等高线套合法提取山顶的不确定性,突出了山顶点格局特征,对数字地形特征研究有参考意义。  相似文献   

9.
灌木园林景观扩张及空间格局演变模型仿真   总被引:1,自引:0,他引:1  
针对城市园林景观快速发展,导致已不适合现今绿化和审美需求的问题,提出灌木园林景观扩张及空间格局演变模型.利用土地使用动态度叙述不同土地的利用类型数量转化和变化速度,通过计算园林扩张强度指数、空间重构定量测度以及人工干扰的强度分析,得出园林景观土地的扩张情况;使用遥感技术和地理信息系统对互相为目的 的空间要素和景观格局分析,得出灌木斑块面积占据景观的总面积百分比、密度指数以及分离度指数,采用热力学熵修正玻尔兹曼值,计算景观熵值,完成空间格局演变模型.仿真结果表明:将模拟的景观数据与真实数据对比,二者数据分布情况非常接近,以此可以证明构建的模型演化效果良好.  相似文献   

10.
利用研究区1977、1985、1999年三个时相遥感数据,获得景观格局类型分布及特点,将景观格局类型进行重组,获得近50年来长白山地区景观格局演变过程,为了简单直观地反映长白山地区生态环境演变规律性,从景观格局单元演变方式、景观格局“增减”进行研究,得出主要结论为长白山地区具有特殊的纵向结构和横向结构的景观梯度特征和内部结构特征,并且景观梯度特征与流域地形梯度以及地貌结构特征相协调。长白山地区景观结构在人类活动干扰和自然条件变化发生了巨大变化,景观纵向结构从低部向上移动,横向结构从明显的景观类型梯度特征变化为单一类型景观,而景观内部结构特征则表观破碎化,为此提出景观格局过程可持续发展的生态策略。  相似文献   

11.
Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.  相似文献   

12.
European Community policy and the market   总被引:1,自引:0,他引:1  
Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.  相似文献   

13.
融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。  相似文献   

14.
为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.  相似文献   

15.
Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.  相似文献   

16.
This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.  相似文献   

17.
Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008  相似文献   

18.
Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.  相似文献   

19.
In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.  相似文献   

20.
《Information & Management》2016,53(6):787-802
Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号