一种基于低通滤波的宜兴市OMIS-Ⅰ成像光谱数据辐射畸变校正方法

研究目的:探讨模型简单、实用的机载成像光谱数据辐射畸变校正算法,为土地利用/覆被研究提供辐射质量优化的图像.研究方法:理论分析与实证研究法.研究结论:由于"太阳-目标-传感器"的相对几何关系发生变化,使得不同空间位置的相同地物辐射亮度值发生变化,这种辐射畸变称其为几何辐射畸变更为合理;基于低通滤波的辐射畸变校正算法,模型简单、方法实用,实现了研究区128波段OMIS-Ⅰ机载成像光谱数据图像辐射畸变的有效校正.     

黄河河口湿地信息遥感提取研究

本文通过几何校正、图像选取以及图像增强等方式进行了遥感影像的预处理,为准确地提取湿地信息提供了数据基础.在舍弃单纯的传统监督分类和非监督分类的前提下提出了一种利用分层提取地物信息的新方法:即,首先根据地物的光谱特征采用模型法对有水的湿地进行提取,然后用非监督分类对其它湿地类型进行提取,最终得到了湿地类型分布图及其相应的面积.     

莱索托地区北京一号全色影像几何校正方法研究

研究目的：确定莱索托地区北京一号全色影像几何校正方法。研究方法：基于线阵推扫式模型和投影变换模型的几何校正方法,采用真实的莱索托境内平地、高山地两景北京一号全色影像进行试验。研究结果：基于投影变换模型的莱索托地区北京一号全色影像几何校正方法比基于线阵推扫式模型的几何校正方法具有相当或更高的精度。研究结论：投影变换模型可用于莱索托地区土地利用遥感影像图的制作。     

基于快速定点学习算法的高光谱遥感信息提取

高光谱遥感通过航空或航天成像光谱仪获得地物的连续光谱信息,可探测到普通遥感不能探测到的物质。而独立成分分析技术是一种基于信号高阶统计特性的分析方法,在利用该方法进行高光谱数据处理时,将待识别的地物作为独立成分表示出来,可得到地物之间的分离度最大化。通过对高光谱遥感图像数据的特性进行分析,使用USGS光谱库中的矿物光谱作为端元信号,构造模拟的高光谱遥感图像,证明了快速定点学习算法在高光谱遥感矿物蚀变信息提取中的有效性。     

高海拔地区TM遥感数据信息的提取与DEM获取研究

本研究以Landsat TM遥感数据为研究对象,以杂谷脑河流域为例,从遥感数据的几何校正、最佳波段选择、图像融合、图像裁剪、土地分类和图像的解译角度进行了处理.之后,将校正后的数据进行了矢量化并得到DEM,在DEM的基础上进行了高程、坡度、坡向方面的分析,得到了有利于LUCC分析的可靠数据.     

基于图像和光谱技术的倒伏冬小麦产量评估研究

倒伏作物产量评估是作物倒伏灾害综合评估中的一项重要指标.针对传统倒伏作物产量评估方法的不足,该文提出了一种基于图像处理技术和光谱分析技术的倒伏冬小麦估产方法.研究首先通过冬小麦倒伏模拟试验,人工造成冬小麦倒伏,采集不同倒伏等级冬小麦RGB图像数据、冠层光谱反射率数据,并测量倒伏冬小麦产量.然后,通过RGB图像获得颜色、纹理特征,通过光谱反射率获得光谱吸收、红边和植被指数特征,取与倒伏冬小麦产量最为相关的23个特征量作为产量预测模型的输入变量.最后,使用粒子群算法优化径向基权值并建立估产模型,通过三个倒伏时期的光谱和图像指标估算倒伏冬小麦产量.结果表明,模型估算精度为98.2％,该模型能满足非接触定量化的倒伏冬小麦产量评估需求.     

中巴资源卫星数据(CBERS-02)在土地调查中的应用

研究目的:以CBERS-02 CCD数据作为土地利用遥感调查信息源开展应用研究。研究方法:对数据质量进行综合分析、方法比较和实证研究。研究结果:(1)通过对CBERS-02 CCD数据经绝对辐射校正和大气订正,图像质量得到较好地改善,各波段能量相对趋于均衡并能客观反映土地覆被真实状况。(2)通过开展标准分幅正射影像图制作及精度评价,显示CCD图像能够满足1∶5万和1∶10万基本比例尺数字影像图制图要求。(3)通过对中巴数据的图像处理、影像分类与信息自动提取方法研究,分类结果均达到了较好的精度要求。研究结论:随着CBERS-02数据质量不断改善,在宏观尺度上,中巴卫星遥感数据在用于土地调查及提高土地管理方面,将会发挥重要作用。     

基于MAPGIS平台的遥感技术用于土地利用动态监测

主要以SPOT4卫星遥感数据为主要数据源,基于MAPGIS6.5平台对漠河县土地利用动态遥感监测研究项目的运作过程为例进行阐述;首先明确土地利用动态监测的具体内容和技术路线,然后对数据进行预处理,数据的配准和几何校正,图像融合以及信息采集的方法与手段进行了探讨;最后对作业的内、外业主要过程及应提交的成果作了介绍。     

基于GF-1 PMS影像的柠檬种植面积估算

为应用国产高空间分辨率影像快速、准确估算丘陵区柠檬种植面积,文章基于GF-1 PMS影像使用不同数据预处理及分类法估算柠檬种植面积。通过对影像进行大气校正、数据融合、滤波等处理,分别得到光谱反射率数据、融合影像和纹理特征数据(分辨率分别为8m、2m、2m)。通过可分离性分析,发现荒草地和未成林柠檬的可分性最差,二者在光谱反射率数据、融合影像和纹理图像中的可分性数值均小于1.8,是影响柠檬分类精度的主要因素。基于最大似然法的分类精度评价结果显示,纹理图像数据估算精度好于8m分辨率的多光谱反射率数据和2m分辨率的融合图像,适当的影像预处理有助于提高监督分类精度。对比基于最大似然法的精度,基于面向对象法的柠檬面积估算精度达95.09%,高于监督分类法的,使用GF-1 PMS影像估算柠檬面积最优方法为面向对象法。该研究为应用国产高分辨率遥感数据快速、准确估算丘陵地区果树种植面积提供了相关参考。     

无人机高光谱遥感数据在冬小麦叶面积指数反演中的应用

[目的]无人机高光谱遥感是获取田间尺度作物生长参数的新型手段,如叶面积指数(leaf area index,LAI)的无人机快速观测对作物生长监测具有重要意义。[方法]研究以河北省衡水市冬小麦为研究对象,利用以多旋翼无人机为平台搭载Cubert UHD185成像高光谱传感器获取了冬小麦乳熟期的无人机高光谱影像数据;在无人机飞行的冬小麦试验田,利用LAI 2200进行了同步观测试验。该研究利用植被辐射传输模型PROSAIL模拟小麦冠层反射率数据,进而模拟9种植被指数(RVI,NDVI,EVI2,OSAVI,MSAVI2,TCARI/OSAVI,RENDVI(red edge NDVI),MSI,S2REP)。将模拟的植被指数与LAI进行相关性分析,分别构建LAI反演模型并通过拟合效果选择最优的反演模型。然后基于LAI最优反演模型利用无人机高光谱遥感数据反演冬小麦乳熟期的LAI。最后利用地面实测LAI数据对反演结果进行了验证。[结果]9种植被指数中包含红边波段的RENDVI和S2REP与LAI具有高度相关性,而且消除了在小麦LAI高值区时其他植被指数对LAI饱和的问题。基于RENDVI指数模型模拟的LAI与模型模拟的LAI之间RMSE为0.51,无人机高光谱数据LAI反演结果与地面实测值高度拟合(R2=0.83,RMSE=0.16,NRMSE=10%,n=25,P0.001),因此RENDVI是用于估算LAI的较理想的植被指数。[结论]无人机高光谱是获取小麦LAI的有效手段,该研究为利用无人机高光谱数据监测作物生理生态参数提供了参考。     

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.     

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.     

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.     

Agrarian Poverty,Nutrition and Economic Class – A Study of Gujarat,India

This paper analyses poverty and calorific undernourishment in the Indian state of Gujarat, where high and market‐led industrial growth has resulted in rapid economic improvement. The study is carried out through a combination of secondary and survey‐based data. We conclude that the neoliberal agenda of uncontrolled, outward‐looking growth has not resulted in significant reduction of poverty or malnourishment in rural areas. Furthermore, while land ownership is officially used as a proxy for wealth distribution, class position appears a better predictor of poverty status in the rural areas than landownership per se. At the policy level, there is a need to revive the agrarian economy and create new non‐agricultural assets, and the primary focus in the state must shift to the distribution of created assets rather than a single‐minded focus on growth.     

Does sustainable agricultural growth require a system of innovation? Evidence from Ghana and Burkina Faso

This paper tests the ‘systems of innovation’ hypothesis for a selection of crops in Ghana and Burkina Faso that have shown significant growth in production over an approximately 20-year period. The question is whether such growth can only occur if supported by a system of innovation. Using two indicators (a common understanding on objectives and priorities, and a high level of interactivity), we find little evidence for the existence of anything that might be considered a high functioning system of innovation.     

Local impacts of industrial tree plantations: An empirical analysis in Indonesia across plantation types

The values ascribed to industrial tree plantations are often controversial. Hence knowledge of their perceived impacts is important for improving their integration in rural landscapes. In 2016 we conducted household surveys with 606 respondents living in villages adjacent to acacia, teak and pine plantations across three islands in Indonesia (Java, Borneo, Sumatra). Results show that perceptions toward pine and teak plantations tend to differ from those toward acacia pulpwood plantations in several ways. Pine and teak plantations are perceived to have a higher number and variety of benefits and services, a higher number of positive impacts, a better environmental record, and to present more opportunities to local people for use of plantation land and products for improving rural livelihoods. In addition, we find that villagers around acacia pulpwood plantations tend to seek economic development and infrastructure to open up remote areas, yet their expectations were often only partially met. Recommendations from our analysis include: the role of the State in plantations must be clarified and potentially reinforced; the role of institutions as intermediaries is fundamental; and contributions by communities to design of management plans should be accommodated.     

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.     

Upstream demand for water use by new tree plantations imposes externalities on downstream irrigated agriculture and wetlands*

Large‐scale tree plantations in high rainfall upstream areas can reduce fresh water inflows to river systems, thereby imposing external costs on downstream irrigation, stock and domestic water users and wetland interests. We take the novel approach of expressing all benefits and costs of establishing plantations in terms of $ per gigalitre (GL) of water removed annually from river flows, setting upstream demands on the same basis as downstream demands. For the Macquarie Valley, a New South Wales sub‐catchment of Australia’s Murray‐Darling Basin, we project changes in land and water use and changes in economic surpluses under two policy settings: without and with a policy requiring permanent water entitlements to be purchased from downstream parties, before plantation establishment. Without the policy, and given a high stumpage value for trees ($70/m³), upstream gains in economic surplus projected from expanding plantations are $639 million; balanced against $233 million in economic losses by downstream irrigators and stock and domestic water users for a net gain of $406 million, but 345 GL lower mean annual environmental flows. With the policy, smaller gains in upstream economic surplus from trees ($192 million), added to net downstream gains ($138 million) from sale of water, result in gains of $330 million with no reduction in environmental flows. Sustaining the 345 GL flow for a $76 million (406–330) reduction in gains to economic surplus may be seen to cost only $0.22 million/GL; but this is much lower than the market value of the first units of that water to agriculture and forestry.     

Underpayment of Small Producers of Coffee and Cocoa in Sierra Leone

Fieldwork shows that many Sierra Leonean producers do not receive the official producer price for their coffee and cocoa, due to the concentration of buying stations, credit relations, the small quantities offered for sale, and the lack of marketing knowledge of the numerous and unorganized farmers. To the traders underpayment may seem economically justifiable to a certain extent, but to the farmers it means poverty and debt. A new village marketing centre project aims at remedying this situation and has already led to higher prices. Although no longer allowed to take their "just" share from the producers, traders are still willing to deal with the new centres.