GIS及模糊神经网络对西南山地烤烟的评估研究

[目的]基于GIS及模糊神经网络,为未来攀枝花西南山地种植烤烟区域规划提供生态适宜性指标数据。[方法]采用GIS及模糊神经网络技术,通过采集攀枝花西南山地烤烟区土壤和烟叶样品,收集整理攀枝花西南山地气候和地形地貌资料,对烤烟质量以及生产烤烟的生态条件进行相关性分析,从而确定评估西南山烤烟生态适宜性的因子,并对攀枝花西南山地烤烟生态进行适宜性评估。[结果]海拔高度、日照时数和土壤类型为攀枝花西南山地烤烟生态适宜性评估关键因子。四川全省9.52%的土地面积为烤烟最适宜区;烟区39.89%的面积为最适宜区,24.20%的面积为适宜区。[结论]应用GIS技术以及模糊神经网络技术,对攀枝花西南山地烤烟生态适宜性进行了评估,以攀枝花西南山地气候、海拔高度以及土壤类型作为生态适宜性评价因子,证实目前攀枝花西南山地主要烤烟产区,位于最适宜区与适宜区。     

基于资源环境承载力的乡村土地利用空间布局优化——以贵州省开阳县为例

以资源环境承载力为基础开展农业空间适宜性评价，在县域尺度下进行农业生产空间布局优化，对喀斯特地区乡村农业产业布局调整及发展特色农产品具有重要意义。本研究以开阳县为研究对象，从资源环境承载力角度入手，通过构建农业生产空间评价指标体系，采用GIS技术对各项指标进行叠加分析，评价开阳县农业生产空间适宜性。结果表明，开阳县资源环境承载力等级低、较低、中等、较高、高的比重依次为57.07%、29.16%、2.19%、10.09%、1.49%，承载力较低等级与低等级的农用地主要分布在北部、西部与西南部；农业生产不适宜区、较不适宜区、一般适宜区、较适宜区面积、适宜区比重依次为39.15%、20.95%、15.23%、18.03%、6.64%，坡度与土壤质地是影响开阳县资源环境承载力差异明显与农业生产不适宜区面积占比高的主要因素。根据评价结果，将开阳县划分为北部绿色生态农业区、南部山地生态农旅区、西部生态林业区、中东部山地特色农产区四个农业产业区，并提出了开阳县农业空间布局优化对策建议，以期为开阳县优化农业产业布局、发展山地特色农业提供参考依据。     

中国羊草适宜性区划与种植现状分析

草种栽培区划是农牧业发展的必然趋势,通过实行草种区划,不但可以充分发掘利用现有的优良牧草和饲料作物资源,还可以避免有些地区引种筛选的重复劳动和盲目的国外引种的失败。文章以我国主要的优良牧草—羊草为研究对象,开展羊草在我国适宜性区划与种植现状的研究。适宜性区划是基于自然要素的生态适宜性模型,结合牧草生物学特性,综合考虑各因子进行系统分析,同时联系牧草实际生产情况完成,种植现状通过统计数据获得。研究结果明确了羊草在全国生态范围内适宜性的分布区域,提出了我国主要栽培牧草生态适宜区、次适宜区、不适宜区,其中适宜区主要分布在东北区中北部,内蒙古区中东部,黄土高原区部分区域、华北区北端。次适宜区主要分布在东北区中部、内蒙古区北部及中部、华北区中部。根据近10年的统计数据,对羊草在我国的种植现状有了一个初步了解,截止2011年,我国羊草种植面积达66.37万hm~2。研究结果理论上科学,模拟结果上准确。     

基于MaxEnt和GIS的山西省连翘潜在分布及适宜性分析

[目的]连翘是一味常用中药,在山西省分布广泛。预测连翘适宜种植区,有助于优化已有种植区的布局以及科学推广引种适宜种植区域,可为山西省贫困区县连翘合理种植提供参考。[方法]文章基于19个环境相关数据和98个连翘种植区采样点数据,采用最大熵模型(MaxEnt)和GIS空间分析法,构建自然、人文相结合的种植适宜性模型,预测连翘潜在分布及适宜性,筛选主导环境因子并探究其与存在概率之间关系。[结果]连翘在山西省种植的最适宜区、较适宜区、适宜区以及不适宜区面积分别为21 049.74km~2、35 655.15 km~2、44 707.90km~2和65 287.20km~2,分别占山西省总面积的12.63%、21.39%、26.82%和39.16%。其中,最适宜区集中分布在山西省的东南部地区,以临汾市、长治市分布最多;较适宜区分布在山西省南部地区,以运城市、晋城市分布最多;适宜区遍布山西省各个地市,但分布零散,受地形、坡度影响较大,不易形成规模生产,连翘的产量和质量均不高。从农户种植便利度、规模化种植灌溉便利度、农业物资运输便利度叠合分析得出,建议连翘的推广区为晋东南长治市、晋城市半丘陵区和太原市、晋中市交界区。刀切法测试表明,年最低气温、气温季节性变动是影响连翘潜在分布的两个最主要环境因子。[结论]连翘具有很高的社会经济价值,山西省大多数地区均适宜种植;在推广种植时应考虑农户种植便利度、规模化种植灌溉便利度、农业物资运输便利度等影响。     

屯昌县黄金蜜柚精细化农业气候区划

[目的]屯昌县是海南省蜜柚发展的主要产区,基于高覆盖度的区域自动气象观测站点资料,开展屯昌县黄金蜜柚的精细化农业气候区划,将给屯昌县蜜柚的种植推广提供更加科学合理的参考依据。[方法]文章利用2006—2017年屯昌县及周边39个区域气象站资料,结合年平均气温、≥10℃年有效积温、1月平均气温、极端最低气温4个黄金蜜柚气候区划指标,建立区划指标与经度、纬度和高程等因子的多元线性回归模型,小网格推算综合气候适宜性区划指标,绘制屯昌县黄金蜜柚农业气候区划图。[结果]最适宜区主要分布在乌坡、南吕、屯城、新兴等乡镇;适宜区主要分布在南坤、西昌、枫木、坡心镇大部分地区;次适宜区和不适宜区主要分布在南坤镇和枫木镇交界的山区。[结论]所构建的县级农业气候区划方法可为当前特色优势经济作物推广种植提供有效借鉴,区划结果对当地作物扩种、引种具有重要的指导意义。     

基于GIS的吉林省马铃薯种植气候适宜性精细化区划

[目的]为合理利用吉林省气候资源、优化吉林省马铃薯种植布局,基于气候和马铃薯生长周期开展吉林省马铃薯种植气候适宜性区划研究具有重要意义。[方法]文章以1981—2010年吉林省及周边51个气象监测站点的逐日气象资料为基础,根据吉林省的气候特征、马铃薯的块茎增长速度、生育周期等特点,确定以生育期平均气温、生育期降水量、生育期日照时数、生育期≥10℃有效积温及7月份平均气温作为气候区划指标。采用GIS技术提取坡度和坡向等空间信息,将0.01°×0.01°网格作为可推算的最小空间单元,建立基于地理关系的马铃薯种植气候因子空间分析模型推算各气候要素,并对气候区划指标进行残差订正,最后依据马铃薯气候适宜指数等级指标进行气候区划。[结果]吉林省马铃薯种植最适宜区主要分布在中西部平原及丘陵地区,占总面积的49.4%;适宜区主要分布在中东部丘陵及低山地区,占总面积的36.9%;次适宜区主要分布在高海拔寒冷地区,占总面积的13.7%。将区划结果与吉林省马铃薯种植状况进行对比,验证了以上区划方法的科学性和合理性。[结论]研究结果可为吉林省各区县马铃薯种植生产布局提供参考依据。     

大豆种植适宜性精细评价及种植合理性分析——以东北三省为例

该文建立了一套涵盖自然和经济影响因子的大豆适宜性评价指标体系,并以东北为例进行了适宜性的研究;指标体系中不但考虑了温度、降水和日照气候3个要素在不同生长期对于大豆种植适宜性的影响,还应用了基础设施、科技进步及农民意愿等社会经济因子评价大豆生长适宜性。在获取东北三省大豆适宜性等级图的基础上,将其与东北三省实际大豆种植区域进行对比,结果发现:(1)东北三省大豆种植适宜性属于中上水平,适宜区、中间等级区及非适宜区的面积分别为9.09万km2,11.45万kkm2和7.99万km2,约占东北全境面积的11.5%,14.49%和10.11%;(2)松嫩平原是最适合于大豆生长的区域,而三江平原由于日照等因素并非大豆种植的绝佳地带;(3)通过对比计算,适宜区、中间等级区及非适宜区与大豆实际种植区符合面积分别占大豆实际种植面积的24.78%,46.30%和28.92%,而黑龙江省为15.39%,51.70%,32.91%,说明黑龙江省大豆种植结构略欠合理。在研究结果基础上,建议农业及相关部门在保护农民切身利益的情况下适当调整大豆种植的空间结构。     

陕南移民安置区选址空间适宜性评价*——以勉县为例

[目的]旨在构建具有较强实用性和可操作性的安置区选址空间适宜性评价指标体系,为陕南移民工程科学选址提供借鉴。[方法]以陕南汉中市勉县为研究对象,选取自然、社会经济、生态3个方面共15个指标构建移民安置区选址空间适宜性评价指标体系。利用GIS空间分析,结合层次分析法和多因素综合评价模型,将勉县全域划分为安置区选址最适宜区、一般适宜区、较不适宜区和不适宜区4个等级,并对已建安置区的空间适宜性进行了评价。[结果]最适宜区、一般适宜区、较不适宜区和不适宜区的面积分别为270. 19km~2、499. 48km~2、894. 07km~2、742. 25km~2,分别占全县总面积的11. 23%、20. 76%、37. 16%、30. 85%;最适宜区主要分布于青羊驿镇中西部,褒城镇、老道寺镇、勉阳镇、周家山镇等镇的南部,以及温泉镇和定军山镇的北部。一般适宜区多分布于最适宜的外围;现有的80个已建安置区中,有30个处于最适宜区,36个处于一般适宜区,11个处于较不适宜区,3个处于不适宜区。[结论]陕南移民安置区建设应在空间适宜性评价基础上做到科学选址,合理布局,保障安置区的可持续发展和移民搬迁后的安居乐业。     

基于AHP-GIS的西北干旱区聚落选址适宜性评价研究——以吐鲁番市为例

[目的]西北干旱区存在自然环境劣势,其聚落的分布直接影响着土地利用的集约程度,因此构建干旱区聚落选址适宜性评价体系具有重要的现实意义。[方法]文章采用层次分析法(AHP)确定各评价因子的权重,利用GIS技术及评价模型研究聚落选址适宜性分布,为其规划建设提供科学依据。[结果]裸地(61.46%)和草地(30.09%)是研究区主要景观。吐鲁番市聚落选址空间分为极适宜区、高适宜区、中适宜区、低适宜区和不适宜区5个类型,聚落中适宜区及以上所占比例仅为26.8%;极适宜区(4.09%)主要分布在吐鲁番盆地中部的博格达山南部地带;高适宜区(6.39%)分布在极适宜区周围的河谷边缘地带以及部分丘陵缓坡区;中适宜区(16.32%)分布在地形起伏较大区域,同时受盐碱地影响,植被覆盖度较低、生态系统结构较差;低适宜区(40.49%)分布在盐碱地以及山区裸岩,植被稀疏、生态环境差;不适宜区(32.71%)集中连片分布在盆地南北端,生态条件更恶劣。[结论]由于特殊的地质地貌条件的制约,吐鲁番市聚落选址空间适宜性较低,因此城市聚落选址建设中应充分结合当地土地利用现状和发展需求,科学布局,实现聚落选址适宜区土地的集约利用。     

海南岛橡胶树栽培适宜性评价初探

[目的]天然橡胶是国民经济建设不可缺少的重要战略物资,为提高橡胶单位产量,防止盲目扩种造成不必要的损失,开展橡胶树栽培适宜性评价具有重要意义。[方法]根据橡胶产量与气候、地形、土壤等相关因素的分析,提出了利用橡胶气候适宜性因子、地形、土壤因子作为主要的评价因子,并采用层次分析法确定各评价因子的权重值,开展海南橡胶树栽培适宜性评价。[结果]海南岛橡胶树栽培高适宜区分布在文昌的西北部、儋州、昌江、琼海、万宁、陵水等地;中适宜区主要分布在临高、澄迈、定安、文昌、屯昌等地;低适宜区主要分布在东方、乐东、五指山等地。[结论]橡胶树栽培与气候、土壤、地形等要素密切相关,基于气候—地形—土壤的橡胶树栽培适宜性评价结果能整体反映海南岛橡胶种植区域适宜程度的空间差异,对海南岛橡胶生产具有重要的参考意义,有利于提高橡胶种植的经济效益。     

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.     

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.     

森林生物多样性评价模型的改进

针对2002年的评价模型中的不足,提出了新的改进后的森林生物多样性变化的评价模型,并在我国第六次森林资源清查(1999～2003)资料的基础上,对1973～2003年我国森林生物多样性的变化进行了补充评价。评价结果表明:我国森林生物多样性的压力越来越大,压力指数由1973年的100,上升到2003年的199.10,上升了1.99倍;森林物种多样性总体的下降趋势已有一定幅度的改变,森林物种多样性指数增加了31.12%。森林生态系统多样性和森林生物多样性先逐渐上升,尔后又下降,第六次森林资源清查时又有所恢复,并分别上升了4.67个百分点和17.90个百分点。     

Trust-A monolithic panacea in land use planning?

Although trust research has been extensive and substantial, the constitution and actual merits of trust in land use planning remain nebulous. What do participants of a local land use planning process actually mean when they say they trust the planning committee? How important is participants’ trust in the planning committee in shaping their perceptions of the planning process and their cooperation in it? To explore the everyday meaning of trust in the specific context of local land use planning, semi-structured interviews with the participants of a local planning project in Switzerland were conducted (n = 9). Based on these results, the constitution and the relevance of trust in the responsible planning committee among a wider circle of participants were assessed (n = 66). The results show that participants trust the planning committee if they perceive its members as competent, honest, open, fair, reliable, reciprocating, respectful and committed. Interestingly, a considerable part of trust in the planning committee hinges explicitly on whether the committee incorporates the personal interests of the participant. Trust is indeed vital to participants’ belief that a meaningful discussion and cooperation with the members of the planning committee is possible. However, trust is neither a guarantee for people's approval of planning decisions nor for their cooperation. One implication of the findings is that in order to evaluate trust-building practice comprehensively, it is necessary to first understand the specific everyday meaning of trust for ‘real people’ in real planning processes.     

转变地质工作发展与服务方式的实践和建议

天津市地矿局注重加快转变经济发展方式,发挥地质工作优势,推进低碳清洁能源的开发利用创新和技术进步,紧紧依托地质工作的人才、技术和行业优势,加大清洁环保资源的勘查、研究、开发、利用。针对天津市水资源缺乏的情况,积极加强后备和应紧水源勘查。按照“两种资源,两个市场”的思路,通过实施中外合作勘查项目,以境外勘查工作为载体和平台,实施引进来和走出去战略,为天津市经济社会发展提供地质技术支撑。     

Agricultural Land in Vietnam: Markets Tempered by Family, Community and Socialist Practices

Since the late 1980s, markets involving agricultural land have emerged in the Socialist Republic of Vietnam. One major reason is that collective farms, previously a central feature of the country's political economy, ended. And a major reason for that was villagers' everyday politics gnawed the underpinnings of the collectives until they collapsed. Rural households, for the most part, wanted to farm separately. Today they do. Land is not privatized, however. Farming households have land use rights, not ownership. This tempers markets, as do other conditions arising from contending schools of thought in Vietnam about how land should be used, distributed and regulated.     

Conservation agriculture (CA) in Tanzania: the case of the Mwangaza B CA farmer field school (FFS), Rhotia Village,Karatu District,Arusha

This project was initiated to promote conservation agriculture (CA) in Tanzania so as to improve the food security and rural livelihood of small- and medium-scale farmers through the scaling-up of CA as a sustainable land management (SLM) tool as well as increasing the numbers of SLM-CA farmer field schools (FFS) in communities. The project had two phases from 2004 to 2010. It was funded by a Government of Germany trust fund and implemented by the Food and Agriculture Organization of the United Nations (FAO) and the Ministry of Agriculture in Tanzania. The project pilot districts include Arumeru (Arusha and Meru Councils), Karatu, Babati, Hanang and Moshi districts. CA has been shown to offer positive elements that could contribute to fighting hunger and poverty.     

Successful Practices in California Wine Exporting

Abstract

California is one of the world's largest wine producers, yet it has exported only a small portion of its products. Many US wineries want to pursue opportunities in foreign markets but only a few are actually doing this successfully. Therefore, this study attempts to identify the successful practices of 12 California wineries that have achieved their financial targets and other export goals. A qualitative research design of in-depth interviews was employed. Results indicate that there are 5 major success factors, with the two most important being the foreign partner relationship and top management vision and commitment to exporting.     

Time Allocation Decisions Associated with Job Market Preparation: Undergraduate Perceptions versus Market Realities

A survey of agribusiness firms identifies characteristics associated with above average starting salary offers in the allied fields of agribusiness, agricultural economics, business, and economics. A complementary survey is made of students at Texas A&M University and University of Georgia. Results show that firms value work experience and leadership experience more than students do, whereas students value raising grade point average and interview preparation more than do firms. Students seeking a firm's maximum starting salary offer will need to enhance academic performance with substantial work experience and leadership experience.     

Developments in the Doha Round and WTO dispute settlement: some implications for EU agricultural policy

Progress in the Doha Round is assessed against the changes tothe common agricultural policy (CAP) brought about by the Fischlerreforms of 2003–2004, and that proposed for sugar. Anelimination of export subsidies could place EU exports of processedfoods at a competitive disadvantage because of high sugar andmilk prices. Provided the single payment scheme falls withinthe green box, the likely new limits on domestic support shouldnot be problematic for the post-Fischler CAP. However, an ambitiousmarket access package could open up EU markets and bring pressurefor further reform. If there is no Doha agreement, existingprovisions will continue to apply, but without the protectionof the Peace Clause; and increased litigation is likely. FurtherCAP reform is to be expected.