水稻空间分布遥感提取研究进展与展望

水稻是我国三大粮食作物之一,其空间分布受自然条件和农业发展状况的影响,变化显著。研究水稻空间分布遥感提取是当前农业土地变化科学的热点和难点。通过对国内外研究的回顾,该文系统归纳了近年来水稻空间分布遥感提取的数据源、特征量及分类算法最新研究进展,并对其未来研究方向进行初步探讨。首先从遥感数据源方面,水稻面积监测主要采用多光谱光学影像,同时高光谱数据和雷达数据也正逐步推广应用。其次从遥感分类方法及其对应的特征量方面,包括监督和非监督分类、智能化分类算法（神经网络、支持向量机、决策树及随机森林算法）、面向对象分类、多时相植被指数法及综合提取算法等分类方法,其主要对应的特征量各有差异。最后,结合我国水稻空间分布遥感提取的实际状况,提出构建全国长时间序列水稻物候历和高时空分辨率时序NDVI数据集,大力发展基于多时相遥感分类方法和建立分层的面向对象分类方法,以及加强水稻种植北界、种植重心迁移等动态变化监测研究的建议,推动我国水稻遥感动态监测和农业土地变化科学的发展。     

尺度变化对油菜种植面积遥感监测精度的影响

农作物种植面积监测是遥感估产的基础工作之一,监测结果的精度直接影响到数据的可信度和可用性。随着多光谱和多空间分辨率数据集的日益普遍,多尺度遥感数据源的综合应用是进行大范围农作物种植面积遥感监测业务化运行的必然趋势,因此尺度变化对农作物种植面积遥感监测精度影响的研究势在必行。该研究采用高空间分辨率的多光谱遥感影像进行油菜种植面积提取,对其提取结果进行基于简单多数原则的尺度转化,得到不同空间分辨率的提取结果,通过与地面实测样方数据构建误差矩阵进行精度分析,分析不同空间分辨率影像对作物种植面积遥感信息提取精度的影响。运用多种精度评价指标,从不同空间分辨率、不同监测方法、不同遥感监测时相等角度系统分析了农作物种植面积遥感测量中的尺度效应问题。为基于多尺度遥感数据综合应用的农作物种植面积遥感监测业务化运行中的数据选择和精度保证问题提供理论与实验基础。     

铁尾矿资源单金属回收利用模式研究

通过对我国铁尾矿资源类型划分和资源量的统计,河北省和辽宁省聚集量最大。截止2010年,全国铁尾矿资源量共计67亿吨,平均品位10％。运用SWO矩阵进行分析,对铁尾矿资源开发利用进行波士顿矩阵划分;其中,宣钢、浙江漓铁尾矿资源处于吉星级别,唐钢、太钢和武钢尾矿资源处于金牛级别。对铁尾矿资源进行单金属回收利用模式计算,依据6．2％临界品位值作为铁尾矿资源经济开发边际品位进行分析,得出可供经济开发的资源量为99589万吨,理论回收铁金属11542万吨。     

鄂州矿山塌陷区基于ENVI的提取方法研究

本文以湖北鄂州矿山塌陷区为研究对象,利用多时相worldview-2遥感影像数据,针对研究区的光谱特征和空间结构特征的特点,采用面向对象的提取方法,提出了基于ENVI软件操作下的矿山塌陷区提取规则。实验结果表明:利用该规则提取塌陷信息是快速准确并能取得良好效果的。     

蚀变矿物信息与构造在高光谱遥感找矿中的应用初探

高光谱遥感蚀变信息提取是地质找矿和蚀变矿物填图的重要方法之一,研究基于现有的机载HyMap高光谱遥感影像模拟的星载高光谱遥感数据,通过光谱特征分析、降噪、端元提取、蚀变矿物填图等高光谱遥感技术结合实验区线性构造,对实验区进行星载高光谱遥感数据找矿应用初探,提取的蚀变矿物组合分布区,可以作为靶区开展进一步预查工作。     

基于无人机遥感可见光影像的农作物分类

[目的]无人机遥感具有高空间、高时间分辨率的优点,并可同时获得光谱和空间信息,因此在农作物分类中备受研究者的青睐。与侧重于从高分辨率RGB图像中提取纹理特征的分类方法不同,文章重点研究如何利用作物在光谱和空间维度上的联合特征尤其是作物高程特征,以实现农作物精细分类。[方法]首先,我们进行研究区域选择和地面实际情况调查,用无人机遥感系统进行可见光影像采集;其次,确定研究区域内农作物分类类别,分别对可见光遥感影像进行可见光植被指数计算及纹理滤波;针对数字表面模型(DSM)数据特点,对两期DSM数据进行差值处理,获得差异数字表面模型数据(DDSM),提取作物高度信息,并根据农作物冠层特性对差异数字表面模型进行滤波处理;最后,进行特征优选及组合,使用SVM方法进行农作物分类。[结果]确定最优分类特征为RGB、红波段对比度、绿波段二阶矩、蓝波段方差、DDSM、DDSM方差、DDSM对比度,分类精度由71.86%提高到92.30%,验证了由DSM影像提取的空间特征可以提高农作物分类精度。[结论]该研究探索了一种基于可见光及空间联合特征的农作物精细分类方法,方法简单可行,设备成本低,在基于无人机低空遥感的样方调查领域中有较大的应用前景。     

基于高分辨率遥感影像的桑树信息提取研究——以广西鹿寨县为例

采用高分辨遥感影像提取农作物信息在北方区域得到了深入的研究和广泛应用,但受到南方地形复杂、气候差异等条件的影响,采用遥感技术提取南方农作物信息的研究甚少。鉴于此,该文以广西鹿寨县为例,采用2012年9月的高分辨率Rapid Eye遥感影像为主要研究数据源,利用面向对象的遥感图像分析方法,结合高程数据模型DEM和GPS野外采集数据,综合桑树在遥感影像上的形状特征、颜色特征、光谱特征、纹理特征、位置特征(拓扑特征)提取桑树信息,并对其分类结果进行精度验证和评价。研究结果表明,提取桑树信息的总精度达到91.96%,Kappa系数达到0.839 1,满足使用的精度要求。面向对象的图像分析方法为高分辨率遥感图像信息提取农作物信息提供了新的思路,该方法与基于像元的分类技术相比,突破了过多地关注地物局部细节而难以提取地物的整体结构信息的缺陷,避免了"椒盐现象"的产生,有效地提高了农作物识别的精度和效率,这对提取广西大宗农作物信息具有一定的借鉴意义。     

高光谱遥感矿产资源探测软件研制与问题探讨

针对高光谱遥感矿产资源探测的处理流程和实施算法,从光谱特征提取、光谱解混及地物分类识别和填图3个方面涉及的关键技术展开了简述。在此基础上基于IDL研发了高光谱遥感资源探测软件。软件集成了影像特征分析、影像信息提取、端元提取、混合像元分解、蚀变填图、成矿远景区分析等功能模块。同时,对存在的问题,从波谱库构建、基于高光谱的资源深部探测、岩矿光谱特性机理分析、高光谱遥感影像高性能处理等方面进行了探讨。     

铜陵矿区尾矿综合利用与生态矿区建设初步研究

随着矿业开采规模的加大,尾矿数量随之增加,尾矿的堆存不仅占用大量的土地,而且产生了严重的生态环境问题;通过复垦、作为井下填充材料、提取有用元素等方法对尾矿进行综合利用,可以实现生态矿区的建设;分析了利用循环经济模式对铜陵矿区尾矿进行综合利用,并将其作为建设生态矿山的重要内容,从而实现矿山的可持续发展。     

村镇退化废弃地遥感监测方法初探

研究目的：开展村镇退化废弃地遥感监测技术分析,为村镇退化废弃地遥感快速监测奠定技术基础。研究方法：选择甘肃省白银市平川区作为研究区域,设计研究区内典型村镇退化废弃地类型,建立不同类型村镇退化废弃地的高分辨率遥感影像特征,提出利用遥感手段快速监测村镇退化废弃地的技术流程,详细描述了其技术方法,进而阐述村镇退化废弃地快速监测移动作业平台的详细功能需求。研究结果：研究区典型村镇退化废弃地在退化废弃前后的遥感影像特征和实地特征均有显著差别,本文的技术流程和方法可以服务于村镇退化废弃地的快速遥感监测。研究结论：采用遥感手段监测村镇退化废弃地在技术上是可行的。     

尾矿植被法治理初探

尾矿作为矿业废弃物,被堆放在尾矿库内．对周围环境造成很大的污染．停用的尾矿库必须进行治理：在几种治理方法中．植被法是一种较为理想的方法．符合我国的国情：主要讨论了利用植被法治理尾矿的具体措施．包括尾矿基质的改良、耐性物种的选择和管理措施的选择等。     

珍惜地球资源,推进尾矿综合利用

尾矿具有二次资源和环境污染、安全隐患等危害的双重特性.有效、合理地利用尾矿,实现尾矿的资源化利用尤为必要.我国尾矿综合利用存在着利用率低、资源浪费、政策支持不足和缺乏科技支撑等问题.目前尾矿利用的主要途径有尾矿再选、充填矿山采空区、复垦和综合利用等.推进尾矿综合利用应转变观念、加强政策支持、实施监督管理和加强技术革新.     

Price transmission between products at different stages of manufacturing in forest industries

The theory of demand and supply implies a positive relationship, or “price transmission” between the prices of products at different stages of manufacturing. This relationship was investigated with quarterly prices of softwood stumpage in the US South, and national prices of forest products, from 1977 to 2002. All prices, net of inflation, were found to be nonstationary and there was no evidence of co-integration between prices. Vector autogressive models, augmented by Granger causality tests and multiplier analysis showed that there was a one-to-one permanent positive response of the southern sawtimber stumpage price to a permanent change in the national lumber price. There was also a one-third permanent positive response of the national paper price to a permanent change in the national pulp price. There was no relation between regional pulpwood prices and national pulp or paper prices. When price transmission was significant, the full adjustment took about 2 years.     

The Effect of the Structural Adjustment Program on the Output,Prices and Exports of Major Agricultural Export Crops in Nigeria

The primary objective of this paper is to examine changes in the level of output, prices and exports of major export crops resulting from the Structural Adjustment Program (SAP) in Nigeria. THere two main sources of data: the Central Bank of Nigeria (CBN) through its annual reports, Economic and Financial Review, and the Nigerian Federal Office of Statistics (FOS) through its Trade Summaries. Although the SAP led to appreciable increases in output and producer prices, its effects on exports were insignificant. The implications of these for the implementation of the program are explored.     

Application of an ecosystem function framework to perceptions of community woodlands

Owners, local residents, government, and conservation organisations can express divergent preferences in the development and management of local woodlands. The perceptions of these four groups were examined, in the context of three community woodlands in Eastern England, using an ecosystem function framework. In a pilot study, residents were able to allocate a relative importance to woodland ecosystem services which were then related to “regulation”, “habitat”, and “production” or “information” functions. However residents also placed importance on negative services or “dis-services” associated with the woodland ecosystem. Therefore a fifth category of “dis-services” was included in the main survey which included 84 local residents, three woodland owners, three government institutions, and six representatives from conservation groups. Each of the four groups placed greatest importance on services associated with habitat (16–39% of the total importance) and information (30–50%) functions suggesting, in this example, mutual interest in the use of woodlands as a habitat or recreational resource. By contrast a potential area of difference was the particularly high importance placed by one owner on dis-services such as fly tipping. In addition the woodland owners placed higher importance (10–20%), than local residents and conservation groups (7–9%), on the productive services of the wood. This suggests a need for communication when production-related operations affect recreation. The ecosystem function framework appears to be a useful approach for highlighting potential tensions and areas of mutual interest in the management of semi-natural ecosystems.     

In Vino ‘No’ Veritas: impacts of fraud on wine imports in China

China is one of the largest wine importing countries in the world and is poised for continued import growth in the future. Increased wine purchases throughout China have given rise to persistent fraud where fake wines are packaged and sold with counterfeit contents and labels. For exporting countries like France, counterfeit wines displace market share, damage foreign brand reputation, and cause distrust in consumers who are aware of counterfeiting problems throughout the country. We examine the impact of fraudulent wine events (as measured by negative media reports) on Chinese wine demand differentiated by supplying country. We employ the Rotterdam demand system and a switching regression procedure to estimate import demand and compare results across different media variable specifications. Results consistently show that negative reports disproportionately affect French wine regardless of how the media variable is specified. This is not surprising because most fraudulent events involve French wine counterfeits.     

土地学科的建设和发展——"土地学科发展规划研讨会"综述

中国土地科学学科发展已取得很大成就,表现为专业教育和人才培养成绩突出、初步形成学科体系、取得大批研究成果.而存在的问题主要是基础理论研究欠缺、独特的土地科学研究方法体系尚未形成、研究角度单一、学术交流质量不高和学科带头人的影响力不足.土地科学学科发展目前面临着巨大的机遇和挑战,应明确土地科学学科发展的基本思路、发展目标及2010-2020年的主要建设任务和保障措施.     

Revealing different understandings of soil held by scientists and farmers in the context of soil protection and management

This paper aims to analyse and draw together results from similar studies in England, Switzerland and France which investigated farmers’ understanding of soil and compared it with that of scientists, researchers and advisors (collectively called scientists in this analysis). A range of methods were used across the three studies and different theoretical approaches, looking at forms of knowledge, local practice of knowledge production and conceptions of reality, were employed to explain the results. Despite the different contexts, methodologies and theoretical approaches in the three studies, the results reveal similar patterns of difference in farmer and scientist understanding of soil. In the English study, farmers demonstrate a ‘know-how’ form or intuitive working knowledge of soil while advisors rely on scientifically established forms of ‘know-why’ and seek to understand and explain soil processes. Similarly in the Swiss study farmers’ and scientists’ differing perceptions are directed and shaped by their respective aims, methods and context of work. In the French study, farmers and researchers are shown to have different conceptions of soil, they attribute different meaning to the same activities, and use different words and language to describe the same features. In all three studies understanding is shown to be cultural and contextual, as such an integrative theoretical framework is proposed.     

An evaluation framework for earthquake-responsive land administration

In recent years earthquakes and their secondary hazards have claimed the largest number of lives of all large natural disasters. Some of the world’s most earthquake-prone zones are also areas of high population density. The impact is magnified by vulnerability factors including non-enforcement of building codes, knowledge gaps, urban poverty and poor governance capacity to manage and reduce earthquake risks. Poor security of land tenure and property rights increases the vulnerability of people and affects their ability to respond to natural disasters.Earthquake recovery and reconstruction provides very significant challenges for land agencies, with these challenges differing from one country to the next due to differences in the local context. Drawing on contrasting case studies in Haiti, Nepal and New Zealand this paper identifies the common post-earthquake land administration functions and challenges that may apply to many contexts. These lessons provide land agencies and other key stakeholders with a summary of the challenges an earthquake poses for land administration at different post-disaster stages. We also discuss the policy and regulatory, institutional, operational and preparedness lessons for land administration. From these lessons we propose a framework for evaluating the earthquake-responsiveness of a land administration system. This framework can be used by a land agency in an earthquake prone region, or where an earthquake has recently occurred, to assess what challenges to land administration might occur in the event of an earthquake, and the preparedness of their land administration system.