基于遥感数据的郑州市植被覆盖度变化研究

植被覆盖度是衡量某一地区植被覆盖状况的指标,某一地区的植被覆盖状况会直接影响到该地区的土壤、水分和气候等自然环境要素。随着中原经济区的快速发展,郑州市作为中原经济区的增长极,发展速度很快,城市扩张迅速。为了研究郑州市的快速发展给生态环境带来的影响,选取植被覆盖度这一指标为研究对象,利用不同时间阶段的遥感影像估算郑州市不同时期的植被覆盖度,通过分析植被覆盖度变化来研究郑州市的快速增长对植被覆盖度造成的影响。结论如下:(1)2000年郑州市的植被覆盖度主要以低植被覆盖为主,2014年以中低植被覆盖度为主,高植被和较高植被覆盖度略有提高;(2)从植被覆盖度变化来看,2000—2014年整个研究区植被覆盖度主要以轻微增加为主。     

1988-2013年广州市湿地时空演变分析研究

湿地具有非常重要的生态服务功能和经济价值.本文以广州市湿地为研究对象,利用1988、2000、2013年三个时相Landsat系列卫星影像结合面向对象遥感解译方法获取湿地空间分布信息;利用土地利用动态度、核密度估计等时空分析方法研究广州市各类湿地的变化特征、过程,并总结了驱动因素.结果表明,1988-2013年间,广州市湿地总面积持续增加,人工湿地在增长过程中处于主导地位;鱼塘湿地在番禺、南沙等区集中分布现象明显;广州市湿地变化的主要驱动因素有经济、人口等因素.     

基于资源三号卫星数据的喀什市研究区的植被信息提取

通过利用喀什市研究区2012年的资源三号卫星影像,使用ERDAS软件首先提取归一化植被指数(NDVI),再使用Arc GIS软件对研究区的植被覆盖度进行估算,最后得出研究区2012年的植被覆盖度分级图,定量地说明了研究区2012年的植被覆盖情况。     

基于TM遥感数据的大庆市植被覆盖变化分析

植被作为生态系统的重要组成部分,是生态系统存在的基础,也是连接土壤、大气和水分的自然"纽带",植被覆盖及其变化是区域生态环境变化的重要指标,对水土保持、气候变化等都具有重要的意义。以大庆市为研究区域,运用归一化植被指数(NDVI)方法估算植被覆盖度,在RS和GIS技术支持下,利用1990、2001和2007年三期的TM遥感数据,对植被覆盖变化进行分析。结果表明:大庆市NDVI平均值在1990-2001年间下降,2001-2007年为上升的趋势。17年间各行政区的NDVI平均值及植被覆盖面积也有不同程度的变化。由此可见,大庆市在生态破坏后开始注重环境的重要性,采取了措施进行生态治理,取得了显著的成果,也说明人类活动是城市植被覆盖变化的重要原因。     

区域植被覆盖度和水土流失量的时空变异研究  ———以江苏省为例

选取1995、2000、2008年为时间变化单元,以江苏省从北到南的20县市区域为空间变化单元,建立植被覆盖度、水土流失量模型,定量分析江苏省植被覆盖度和水土流失量的时空变化特征。结果表明:(1)江苏省的区域植被覆盖度时间变异较大,随时间的推移总体呈上升的趋势,其中新沂的植被覆盖度最高,扬中的植被覆盖度变化最大。(2)20个县市区域的水土流失量随时间的推移总体上有所增加,而如皋、通州、海门、东台、扬中、泰兴和兴化等区域的土流流失状况有所改善。     

基于遥感的土地复垦植被覆盖度评价

研究目的：利用遥感技术对土地复垦后的土地质量评价指标——植被覆盖度进行评价。研究方法：利用ERDAS软件通过建模实现植被覆盖度提取,对结果影像进行分级统计。研究结果：土地复垦后的试验区植被覆盖度比复垦前高。研究结论：评价结果符合实际情况,利用遥感技术对土地复垦后的植被覆盖度进行评价是可行的。     

福州城市热岛效应与土地利用变化关系研究

以福州市区为研究区,分析1988等4个年份热岛效应的变化及其与土地利用类型、植被覆盖度的关系。结果表明:(1)城市核心区与非核心区的平均温度差值不断增大,城市热岛效应显著增强。(2)不同土地利用类型热岛效应程度排序为水体林草地耕地建设用地,强、中等热岛效应区主要对应建设用地,并随着建设用地的扩展而延伸;非、弱热岛效应区主要对应水体、耕地和林草地,非热岛效应区随耕地和林草地的萎缩而减少。(3)不同植被覆盖度平均温度排序为水体高植被覆盖度中植被覆盖度中低植被覆盖度低植被覆盖度裸地,强热岛效应区和中等热岛效应区主要对应裸地,非热岛效应区主要对应高植被覆盖度区域,弱热岛效应区域主要对应低、中低和中植被覆盖度区域,随植被空间萎缩和稀疏化强、中等热岛效应区扩张而非热岛效应区减少。     

基于比值植被指数的建设用地覆盖变化研究

基于中巴资源卫星遥感影像数据,利用比值植被指数对徐州市2001年,2005年,2008年3年的建设用地覆盖情况进行提取,探究比值植被指数应用于建设用地提取的可行性。通过比较2001—2008年间建设用地变化情况,发现徐州建设用地覆盖呈增长趋势,2005—2008年较2001—2005年增速稍缓。结果表明,利用比值植被指数对遥感影像分析,可以快速地获取建设用地覆盖变化情况,为未来几年发展的预测与规划提供参考。     

武汉市土地利用/覆被变化(LUCC)时空特征研究

为揭示武汉市1994—2016年土地利用/覆被变化特征和三峡库区重要节点土地利用状况。利用1994年、2006年和2016年三期LandsatTM遥感影像和基础地理数据,通过目视解译对武汉市土地利用类型进行监督分类,分析武汉市土地利用结构特征、土地利用与覆盖变化的时空格局和重心迁移特征。研究结果表明:1994—2016年间,研究区的草地、水域和城乡、工矿、居民用地增加比例分别为0.48%、0.19%和4.53%;林地、耕地和未利用土地减少比例分别为0.82%、0.70%和0.99%;研究区内30.77%的区县草地面积比例最高,其次是林地、耕地。2016年城乡、工矿、居民用地比例最高的区县占武汉市总区县的50%。1994—2006年间,研究区各用地类型之间的相互转换较多;耕地的动态变化最为明显,总面积减少了972.69 km~2;林地净增加最多,为900 km~2;草地净增加264.38 km~2;城乡、工矿、居民用地净增加39.63 km~2。2006—2016年10年间,土地利用变化面积比例为63.69%;耕地和林地的动态变化最为明显;城乡、工矿、居民用地的转入面积为1738.79 km~2,转出面积为83.93 km~2;水域主要由林地和草地转化而来。22年间耕地的重心迁移最明显,向西南方向偏移29.14 km;草地向西北方向偏移16.59 km;林地向东南方向偏移12.99 km;城乡、工矿、居民用地和水域用地类型的重心迁移量微弱。     

基于NDVI的重庆市渝东北区植被覆盖度研究

对渝东北生态涵养区前后植被覆盖度~([1])做对比,反映该区生态环境的保护力度,评估该区域的退耕还林工作成效,可以为渝东北区乃至全国的植被监测与保护工作提供一定的借鉴。利用空间分辨率为500m,2012、2015年同期的NDVI数据,使用像元二分法~([2])计算得出2012、2015年的植被覆盖度,对比显示该区域植被覆盖度的变化情况。     

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.     

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.     

Malaria incidence and agricultural efficiency in Uganda

The cost of accessing healthcare can be a major determinant of disease prevalence, which in turn has short‐ and long‐term welfare implications on poor households. In response, governments in developing countries often resort to subsidizing the cost of drugs, which, while perhaps easier to administer, may not always be the most effective way of addressing healthcare cost. In this regard, we analyze the impact of different types of household level health expenses on disease incidence and agricultural production efficiency. We use data from the 2006 Uganda National Household Survey, which covered approximately 7,400 households. The results suggest that a 10% increase in consultation, medicine, and hospitalization expenses would reduce malaria incidence respectively by 35.6%, 20.5%, and 21.3 %, which translates into a 1.1%, 0.6%, and 0.6 % decrease in agricultural inefficiency, respectively. The results indicate that helping poor households meet expenses for consultation through subsidies or eliminating consultation fees has a larger impact on malaria incidence and agricultural productivity among poor rural households than subsidizing the cost of medical drugs, the most common avenue chosen by developing country governments in the fight against the disease.