重庆市万州区土地利用变化与粮食生产态势浅析

探讨万州区1997-2003年土地利用变化,尤其是耕地资源变化影响下该区粮食生产情况;运用Mapgis6．5对万州区土地利用结构与布局变化进行分析,应用Dps3．01逐步回归分析模块对耕地面积、粮食播种面积、粮食单产对粮食生产的影响进行分析;非农建设占用及生态退耕是导致万州区耕地数量和质量变化的主要因素;耕地面积与粮食总产量有一定的相关性,粮食播种面积与粮食总产量的相关性较强,而粮食单产与粮食总产量之间的相关性很强;根据万州区实际情况提出应通过建立耕地保护区,提高土地利用率和土地生产效率来保证粮食安全。     

中国近30年影响粮食安全因素分析

近30年我国粮食总产量出现了较大的波动,中国的粮食安全重新引起社会各界的广泛关注。本文在分析我国近30年影响粮食安全因素的基础上,运用定量分析方法,探讨自然资源和人为因素对粮食生产的影响,包括耕地面积、粮食播种面积、有效灌溉面积、农用机械总动力、化肥施用量等因素与粮食总产量的相关关系。结果显示,相关系数依次为:化肥施用量>农用机械总动力>有效灌溉面积>粮食播种面积>耕地面积。     

我国粮食生产主要影响因子的灰色关联动态分析

根据1994～2004年我国粮食生产相关指标的统计数据,运用灰色关联理论对影响我国粮食生产的主要因素进行了关联动态分析,定量分析了粮食总产量与各因子的关系密切程度,指出了粮食单产、粮食播种面积、有效灌溉面积及受灾面积是影响中国粮食生产的最重要因素;提出了相关的发展对策。     

基于指数分解法的中国粮食增量贡献要素研究

随着中国经济发展,粮食生产能力得到了进一步提高。从2003年开始,中国粮食生产连续九年获得丰收,这为稳定粮食总产量、保障粮食供给奠定了基础。本文通过指数分解法,深入研究了影响粮食总产量变化的因素以及其要素贡献率。结果表明,单产和播种面积对粮食总产量的贡献率呈此消彼长的关系。具体来说,单产对粮食总产量的贡献率逐年增加,而播种面积对粮食总产量的贡献率则逐年递减。影响单产的显著因素是农业水利基础设施建设(灌溉面积)、受灾面积、化肥施用量,影响播种面积最显著因素为农产品价格。在未来时期,为了增加粮食产量,稳定粮食供给,需要加强农田水利设施建设、增强防灾抗灾能力、合理使用化肥、完善粮食补贴政策。     

新疆粮食生产动态变化及其影响因素分析

收集整理了1949～2006年新疆粮食生产数据资料,采用定性分析与定量分析相结合的方法分析了新疆粮食总产量、粮食单产、粮食播种面积、人均粮食产量等指标动态变化状况.并运用灰色关联分析法对影响粮食总产量的因素进行了研究,测算了粮食单产、粮食播种面积、农业机械总动力、耕地面积、化肥施用量、有效灌溉面积、受灾面积、总人口、第一产业劳动力等9个因素对新疆粮食生产的影响,在此基础上提出了加强新疆粮食生产的对策建议.     

影响中国粮食生产的因子分析

在建立因子分析模型基础上,本文对中国粮食单产和播种面积的影响因子进行了实证分析。研究结果表明,在粮食单产方面,科技进步水平因子具有较高载荷,对粮食单产的影响力最大,其次是物质投入因子、环境与气候因子和政策因子。对中国粮食播种面积影响最大的因子是资源及科技因子,其次是比较效益及政策因子。上述研究的政策含义是,为稳定和提高中国粮食综合生产能力,要保护耕地资源,稳住粮食播种面积,提高科技对粮食生产的支撑能力,加大粮食生产的投入力度,建立健全粮食生产支撑体系。     

影响粮食生产的因素分析及对策建议

一、影响粮食生产的因素分析粮食生产的稳定增长包含数量和质量两层含义，但首要的是总产量的增长。从计量分析的角度，总产量由粮食播种面积和单位面积产量决定。由于我国土地后备资源有限，且粮食播种面积已占耕地总面积较大比例（７５％），其调整幅度不大；在一定程度...     

影响我国气候旱区粮食生产能力的灰色关联分析

文章根据投入产出分析的相关理论,结合其他学者的研究成果,确定了影响气候旱区粮食生产能力的主要因素。包括粮食作物播种面积、粮食作物种植结构、粮食单位面积产量、有效灌溉面积、农业从业人数、农用化肥施用折纯量、农业机械总动力及受灾面积、财政对粮食直接补贴资金额、年均降水量等。通过选取2000~2013年统计数据,运用灰色关联分析法,对这些因素与气候旱区粮食总产量进行相关性分析,表明财政对粮食直接补贴资金额、农用化肥施用折纯量、粮食单位面积产量、玉米播种面积占粮食作物播种面积比例及受灾面积与粮食产量高度相关,对提升粮食生产能力的影响较大;小麦播种面积占粮食作物播种面积比例、农业机械总动力、有效灌溉面积、农业从业人数、粮食作物播种面积、年均降水量都与粮食产量中度相关,对提升粮食生产能力的影响较小。因此应继续推行政府对粮食直接补贴政策、增加政府对粮食直补资金,同时,增加物质投入、提高农业科技水平、改善农业灌溉条件、调整粮食种植结构、提高粮食单位面积产量、减少受灾面积来提升粮食生产能力,增加粮食产量。     

黄淮海平原区耕地变化对粮食生产能力的影响

耕地变化所产生的直接影响就是粮食安全问题。本依据1991～2001年黄淮海平原区耕地数量和质量变化以及粮食生产变化情况，分析了耕地数量与质量变化对粮食生产的影响，结果表明：耕地数量和质量变化，通过影响粮食作物播种面积和单产，最终影响到粮食总产量。1991～2001年，由于耕地面积减少和耕地质量降低，导致黄淮海平原区粮食总产量损失634.87万吨，占2001年粮食总产量的5.1%。因此，保护现有耕地是保证粮食生产的基础，对粮食安全意义重大。     

河南粮食总产及农业经济发展关键因素分析 ——基于面板数据分析

利用面板数据方法,对河南省农业增加值、粮食总产量、农业机械总动力、农业劳动力、粮食播 种面积、化肥使用量、农药使用量、地膜使用量的对数值进行了面板单位根检验,证实了这8个经济变量 的对数值均为一阶单整,有共同增长的趋势。然后对各变量进行了协整检验,验证了河南省这几个农业经 济变量均存在一阶协整。通过构建不变参数面板回归模型并进行估计,证实了3个结论:（1）粮食播种面 积与化肥使用量对农业增加值以及粮食总产量的影响较为显著,粮食播种面积每增加1%,能使农业增加 值增加1.32%,化肥使用折纯量每增加1%能促使农业增加值增加0.407%。对粮食产量增速影响较为显著 的是粮食播种面积的增速以及化肥使用量的增速,对粮食产量增速影响分别为1.517 0和0.235 4。（2）农 业机械总动力以及农药使用量对农业增加值以及粮食总产量的影响不太明显,影响系数均在0.1以下。 （3）农业劳动力与农业增加值以及粮食总产量均呈现出负相关,农业劳动力对农业增加值的影响系数为- 0.159 3,对粮食总产量的影响系数为-0.056 1。据此提出4个方面的建议:（1）增加粮食播种面积,保证 粮食安全;（2）增施肥料,增加粮食单位产量;（3）科学使用农药,保证食品安全;（4）提高农机化水平, 促进农地流转,以提高农业生产效率。     

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.     

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.     

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.     

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.     

Evaluating Alternative Policy Responses to Higher World Food Prices: The Case of Increasing Rice Prices in Madagascar

Higher world food prices have led many developing countries to adopt policies to mitigate the impact on low-income households. This article sets out a partial equilibrium framework to evaluate the efficiency, distributional, and revenue implications of alternative policy responses. The model is applied to evaluate tariff reductions and targeted transfers in Madagascar. Although lowering tariffs generates substantial efficiency gains, these accrue mainly to the top half of the welfare distribution, and poor net sellers are actually worse off. Developing a system of targeted direct transfers to poor households is likely to be a substantially more cost-effective approach to poverty alleviation.     

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.     

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.     

Transaction Cost Thresholds in International Rice Markets

Recent episodes of high and volatile prices for grains such as rice have raised concerns about their implications for hunger and poverty. We model price relationships between international rice prices and 221 domestic prices in 47 developing countries that import rice. We use a threshold vector error correction model that accounts for transaction costs of trade in spatial price transmission, and an improved regularised Bayesian threshold estimator for threshold models. Our results show that threshold values are higher after 2008 than before, which suggests that transaction costs in international rice trade have increased in recent years. Threshold values are highest for Latin American countries followed by African and Asian countries, and higher for retail than for wholesale prices. Since 2008, price transmission is slower in countries that responded to high and volatile prices with domestic market‐based interventions such as price controls and faster in countries that responded by lowering tariffs and by implementing production support measures.