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1.
选取武夷山土壤垂直带中6个代表性剖面,研究了土壤的形成条件和特点;按照<中国土壤系统分类(修订方案)>,鉴定了诊断层和诊断特性,检索了土壤系统分类名称;随海拔由低到高,依次为湿润富铁土-湿润淋溶土-常湿淋溶土-常湿雏形土等亚纲;并与发生学分类、美国土壤系统分类(USST)以及世界土壤资源参比基础(WRB)等不同分类系统中的土壤类别归属作了参比.  相似文献   

2.
基于遥感数据的流域土壤侵蚀强度快速估测方法   总被引:20,自引:0,他引:20  
以北京延庆县境内的妫水河流域为例, 提出了一种基于遥感数据的土壤侵蚀强度快速估测方法。首先, 利用遥感数据和植被指数模型提取流域内土地利用类型信息和植被覆盖度信息; 其次, 利用数字高程模型数据生成坡度图; 然后, 结合土壤侵蚀强度分级指标, 将坡度图与土地类型图、植被覆盖度图空间叠加, 判断和计算侵蚀强度等级, 结果获得了流域土壤侵蚀强度等级图; 最后, 计算了流域的年平均侵蚀模数。结果表明, 妫水河流域的土壤侵蚀以微度和轻度为主, 所占面积比例为74.88% , 极度和剧烈侵蚀很少, 不到总面积的2%。整个流域的年侵蚀模数估计为1 74611/ km 2·a。  相似文献   

3.
为推广应用中国土壤系统分类 ,本文对自然地理野外实习基地—河北省秦皇岛市石门寨区域的土壤进行系统分类研究。结果如下 :土壤诊断层有淡薄表层、水耕表层、雏形层、水耕氧化还原层、粘化层 ,诊断特性有砂质沉积物岩性特征、石质接触面、半干润土壤水分状况、湿润土壤水分状况、人为滞水土壤水分状况、氧化还原特征、冷性土壤温度状况、温性土壤温度状况 ,土壤类型归属为人为土纲、淋溶土纲、雏形土纲和新成土纲。并与原土壤地理发生分类进行参比及总结地理分布规律  相似文献   

4.
植被覆盖在维持生态系统结构稳定和防治水土流失等方面发挥着重要的作用,海南自1988年建省以来迅速发展,导致海南岛植被覆盖也产生了巨大的变化.为揭示海南本岛地形因子对植被覆盖度的影响以及为海南本岛进一步制定合理的生态环保策略提供依据,基于1988、1998、2008、2017和2020年Landsat-TM/OLI多光谱影像,以海南本岛为研究区域,采用归一化植被指数和像元二分模型进行植被覆盖度提取,通过线性趋势分析海南本岛近30a植被覆盖变化特征.并结合30 m_DEM获取的海、坡度和坡向数据,来进一步探讨海南本岛植被覆盖度在不同地形因子条件下的空间分布特征.结果表明:①1988~2020年海南岛平均植被覆盖度介于0.58~0.88之间,整体呈先下降后上升趋势;②海南岛高植被覆盖主要分布于海南岛中部、西南部和东南部地区,低植被覆盖主要出现在居住区、沿海地区等人为干扰因素较高的地区;③海南岛各等级植被覆盖均随海拔的增加而不断降低,在海拔小于100 m的区域分布面积最大;坡度为0~5°时植被覆盖面积达到最大值,随着坡度的增加,植被覆盖面积呈减少趋势;各等级植被覆盖在阴坡和阳坡的分布面积变化差异不大,主要以高植被覆盖类型为主.  相似文献   

5.
本文对安徽省沿淮地区的黄棕壤、黄褐土、水稻土、砂姜黑土、潮土和石灰土等六种主要土壤的典型剖面进行系统研究,按《中国土壤系统分类(修订方案)》确定了各土壤剖面具有的诊断层和诊断特性,进行了分类检索,得出了这六种典型土壤剖面在中国土壤系统分类中所属的分类单元,并与现有发生学分类进行了参比。典型剖面研究结果表明:这些土壤分别被划归铁质湿润淋溶土土类、粘磐湿润淋溶土土类、简育水耕人为土土类、淡色潮湿雏形土土类、简育潮湿变性土土类、钙质湿润淋溶土土类。  相似文献   

6.
本研究在论述了西马峪滑坡侵蚀体的形成、岩土体特征、滑坡滑动和变形破坏特征的基础上,首先定性分析、定量计算评价了西马峪滑坡侵蚀的稳定性,结果表明,两马峪滑坡侵蚀体处于临界一不稳定状态,最后对西马峪滑坡侵蚀体潜在侵蚀量进行了评估,提出了应当采取工程治理措施,防止滑坡侵蚀灾害进一步加剧,制止水土流失的发生。  相似文献   

7.
甘南地区植被类型及其NPP研究   总被引:1,自引:0,他引:1  
依据草原综合顺序分类系统,利用1950~2000年近50 a全球气候插值数据集,绘制出甘南地区的潜在草地类型图,并对甘南地区潜在草地NPP进行了统计分析。结果表明:甘南草地可分为寒冷潮湿多雨冻原-高山草甸类、寒温湿润山地草甸类、微温潮湿针叶阔叶混交林类、微温湿润森林草原-落叶阔叶林类、暖温湿润落叶阔叶林类、暖温微润森林草原类和暖温微干暖温带典型草原类7类草地;甘南地区NPP年均值在空间上由西北向东南方向逐步增加,NPP总量为23.08 TgC,其中以寒冷潮湿多雨冻原-高山草甸类和寒温湿润山地草甸类草地类型为主;在地形因素中,海拔高度对NPP年均值的影响较明显,随着海拔增加NPP呈下降趋势,而坡度和坡向对于NPP年均值的影响不明显。  相似文献   

8.
本文以浙江省低丘红壤区为研究对象,利用卫星遥感影像构造削弱阴影等干扰的FCD模型,和混合像元法计算植被覆盖度的方法,进行水土流失研究.根据水利部颁布的<土壤侵蚀分类分级标准>,结合植被覆盖度、坡度、利用现状等因子进行土壤侵蚀强度评价.研究结果表明目前红壤区内植被覆盖情况良好,覆盖度基本在30%以上;整体水土流失程度较轻,但是耕地等农用地的侵蚀情况较为严重,特别足红壤区内耕地的强度侵蚀的面积占其总面积的17.65%.另外,耕作侵蚀也是土壤侵蚀非常重要的凶素,在估算土壤侵蚀强度的时候也应重视.目前浙江省需要补充大量耕地以满足社会发展的需要,鉴于红壤水土流失易发的特点,在低丘红壤开发时要重视水土流失的预防和控制.  相似文献   

9.
根据土壤理化性质,分别按照《中国土壤系统分类(第三版)》中的诊断层和诊断特性和中国土壤分类系统的发生分类原则对河南省南部地区具有漂白层的4个代表性土壤剖面进行分类归属,确定其在中国土壤系统分类中属于淋溶土纲,湿润淋溶土亚纲、漂白湿润淋溶土土类及相应的亚类、土族、土系;在中国土壤分类系统中属于湿暖淋溶土亚纲,黄褐土土类,白浆化黄褐土亚类及相应的土属、土种。  相似文献   

10.
针对南方红壤丘陵区水土流失严重这一问题,水利部为此在2014年实施了专门的水土流失综合治理技术标准(SL657—2014)。为精确评估红壤丘陵区土壤侵蚀状况及分析时空演变规律,在新的技术标准指导下,以赣州为例,采用RUSLE模型和HJ-CCD影像,定量分析了该区2008年和2013年土壤侵蚀及时空演变。结果表明:相比2008年,该区域土壤侵蚀状况有了一定程度改善,侵蚀总量由5 867.589t降到5 225.733t;坡度在15~30°是中度及以上侵蚀的主要区域,在250~350m高程范围内土壤侵蚀量达到最大,150~550m范围为土壤发生侵蚀的主要高程区域;赣州西南到东北区域生态环境依旧脆弱,兴国县侵蚀状况有所好转,上犹、崇义、会昌三县的土壤侵蚀呈进一步加剧趋势。  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   

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