海南岛蒸发量的变化特征及其影响因子分析     

施晨晓  羊清雯  王小洁  程洪涛  郑虹晖 《气象科技》2019,47(3):439-449

利用海南岛18个气象观测站1966—2001年逐日20cm口径小型蒸发皿蒸发量及气象要素资料,通过数理统计方法分析了海南岛年和四季的蒸发量变化特征及气象因子对蒸发量的影响。结果表明:从时间上看,海南岛年蒸发量变化呈波动式下降,蒸发量的减少主要出现在春季,冬季和夏季次之。从空间上看,年蒸发量呈东北少、西南多的分布,其大值区主要集中在西南部,小值区主要集中在东北部和中部地区。M-K检验说明年与春冬两季蒸发量的变化呈下降趋势且在1994年前后发生突变。影响蒸发量变化的因子中,日照时数和风速是造成蒸发量减小的主要因子,降水量的影响仅次于风速和日照时数,而气温不是造成海南岛蒸发量减小的主要因子,相对湿度可能是海南岛的蒸发量减小的影响因子。  相似文献   

海南岛橡胶割胶期的气候适宜度变化特征分析   总被引：1，自引：0，他引：1       下载免费PDF全文

陈小敏  刘少军  张京红  陈汇林 《气象与环境科学》2019,42(2):35-41

选取海南省18个市县气象站19612017年逐日气象资料,构建逐月橡胶割胶单要素(温度、日照时数、降水量和降水日数、风速)和综合气候适宜度模型,分析其时空变化特征。结果表明:1)海南岛天然橡胶单要素适宜度对比排序:日照适宜度最高,降水和风速适宜度次之,温度适宜度最低。2)橡胶割胶气候适宜度为0.43~0.80,其中411月较高,适宜割胶;12月至次年3月较低,不适宜割胶。3)天然橡胶割胶适宜度高值区主要分布在海南岛中部地区,该区温度适宜度较高,降水量充足,年平均风速小;低值区主要分布在西部和北部沿海地区,该区主要因为年平均风速大,降雨量不足,易造成干旱;其余地区为适宜度次高值区,该区热量和降水都比较充足,但也容易受高温干旱或风害影响,应予以重点防范。4)19612017年海南岛橡胶割胶期气候适宜度总体呈明显增大趋势,气候倾向率为0.009/10a。  相似文献   

Engaging Diasporas for Development: a case study of Pitcairn Island     

Maria Amoamo 《The Australian geographer》2015,46(3):305-322

Diaspora engagement is a growing trend and many governments, international organisations and policy makers are increasingly focusing on the role of diaspora in development strategies for the homelands. Such policies are predominantly critical to island-dense regions such as the Caribbean and Pacific that have suffered high rates of outmigration during the postcolonial period. One such Pacific island is Pitcairn, a British Overseas Territory, and is the focus of this article. But while most of the literature focuses on the positive benefits of diaspora engagement, this paper examines the dynamics of diaspora (dis)engagement and (dis)affection. Each diaspora has a unique set of needs and capabilities based on its historical experience and the present realities of its countries of origin and destination. While much has been written celebrating the role of diasporas in development, diaspora have also shown themselves to have dual natures, with sometimes conflicting identities and allegiances. Based on analysis of a recent Pitcairn Diaspora Survey and ethnographic data, discussion in this paper reveals that the best intentions of engaging diaspora for development can be impeded by several factors including: (1) the complex nature of identity, place and politics; (2) difficult negotiations between past, present and future intentions of movers; and (3) shifting ‘roots/routes’ and boundaries of identification. Consequently, the paper aims to highlight the realities of settlement and relationships of diaspora space and subjectivity with the homeland.  相似文献   

海南儋州南江褐铁矿矿床地质特征及控矿因素分析          下载免费PDF全文

张志  胡祥昭  郭旻 《地质找矿论丛》2011,26(1):34-38,45

南江褐铁矿产于下石炭统南好组中,矿体呈脉状、透镜状产出,规模较大、品位很高、质量较好.矿区内发育3组断裂,NNE向断裂控制了矿体的产出,并为矿液运移提供通道;兰洋岩体提供了成矿热液和物质来源.从矿床地质特征分析,为先成的热液型铁矿受古地理条件和气候影响,风化淋滤成褐铁矿,在地表出露为铁帽.预测其找矿前景较好.  相似文献   

发扬李四光地震预报的科学思想     

李方全 《地质力学学报》2011,17(1):74-78

李四光教授关于地震地质工作中地震预报方面的重要观点和思想主要包括:地应力变化与地震密切相关;地震活动带中也存在相对安全的地区(“安全岛”理论);地震地质调查是地震预报的基础;地震是可以预测的,地应力的变化过程是地震预报的关键.他的“安全岛”理论及地震预报思想至今仍有着十分重要的理论意义和现实意义.  相似文献   

海南岛西部青白口系石碌群褶皱变形特征及其控矿分析     

陈沐龙  李孙雄  官军  曾雁玲 《华南地质与矿产》2011,27(4):265-272

青白口系石碌群属于一套海相沉积经变质的以细粒碎屑岩、泥岩及镁质碳酸岩夹火山岩为原岩的变质岩系组合,赋存有沉积变质型铁矿和热液型铜钴矿。岩石经历了多期次变形作用的改造,总体表现为由褶皱变形往韧脆性断裂变形演化的特征,褶皱变形包含了三个变形序列的构造形迹组合。与铁矿主成矿期密切有关的NW向石碌复向斜属于海西．印支期造山运动...  相似文献   

海南石碌铁矿床构造变形特征及其与铁多金属成矿富集的关系   总被引：1，自引：0，他引：1  

许德如  吴俊  肖勇  陈福雄  王力  刘朝露  王智琳 《地质通报》2011,30(4):553-564

海南石碌铁矿曾被誉为“亚洲最大的富铁矿”,其形成、定位与褶皱变形及伴随的剪切、塑性流动等构造密切相关。石碌矿区构造变形大致分为早期(D1)复式向斜的形成时期、晚期(D2)褶皱叠加和剪切变形时期。后者又进一步分为韧-脆性变形(D2a),脆-韧性变形、层间滑脱断层形成(D2b)和脆性变形、矿体破坏(D2c)3个阶段。石碌铁矿床受NW—SE向复式向斜及其与NE—NNE向褶皱叠加所形成的横跨或斜跨褶皱的严格控制;褶皱过程所伴随的剪切变形和高温塑性流动是富铁矿形成的重要机制。复式向斜轴部,尤其是2期向斜褶皱轴的叠加部位往往可发现厚大的富铁矿体。  相似文献   

3S技术在海南省海岸保护利用规划中的应用     

赵薛强  林桂兰 《台湾海峡》2011,30(3):330-335,445-447

利用3s技术强大的空间信息处理和管理能力及制图能力,实现了在海南省海岸保护利用规划中多源地理数据采集处理、专题信息分析提取、规划图集编制和规划信息管理系统的建立等．结果表明：采用3S技术能够较好地处理海南省海岸保护利用规划中涉及的陆图、海图、遥感图、海洋功能区图、相关规划图和项目用海图等基础地理数据,以及现场调查、勘测数据的空间位置关系;提取了海南岛海岸类型、海岸开发利用现状等专题信息;结合海南社会经济发展对海岸资源开发利用的需求和生态环境保护要求,划分基本功能岸段,总体为北部海岸以港口、旅游岸段为主,东部海岸以旅游、渔业岸段为主,南部海岸以旅游、港口岸段为主,西部海岸以港口、渔业岸段为主．  相似文献   

A western boundary current east of New Caledonia: Observed characteristics     

Florent Gasparin  Alexandre Ganachaud  Christophe Maes 《Deep Sea Research Part I: Oceanographic Research Papers》2011,58(9):956-969

Waters from the South Equatorial Current (SEC), the northern branch of the South Pacific subtropical gyre, are a major supply of heat to the equatorial warm pool, and have an important contribution to climate variability and ENSO which motivated the Southwest Pacific Ocean and Climate Experiment (SPICE, CLIVAR/WCRP). Initially a broad westward current extending from the equator to 30°S, the SEC splits upon arriving at the major islands and archipelagoes of Fiji (18°S, 180°E), Vanuatu (16°S, 168°E), and New Caledonia (22°S, 165°E), resulting in a complex system of western boundary currents and zonal jets that feed the Coral and Solomon Seas. We focus here on the formation of one specific jet feeding the Coral Sea, the North Caledonian Jet (NCJ). Using a combination of recent oceanographic cruises, we describe the ocean circulation to the northeast of New Caledonia, where the SEC forms a western boundary current that ultimately becomes the NCJ. This current, which we document for the first time and propose to refer to as the East Caledonian Current (ECC), has its core located 10-100 km off the east coast of New Caledonia, and extends vertically to at least 1000 m depth. Water mass properties show continuous westward transports through the ECC, from the SEC to the NCJ in both the South Pacific Tropical Waters in the thermocline and Antarctic Intermediate Waters near 700 m depth. The ECC extends about 100 km horizontally; its average 0-1000 m transport was estimated at 14.5±3 Sv off the north tip of the New Caledonian reef, with a maximum of 20 Sv in May 2010. South of that the upstream branch of the ECC east of the Loyalty is close to 8 Sv suggesting an important additional contribution from central Pacific waters carried by the SEC at 16°S and diverted to our region through the western boundary current system east of Vanuatu.  相似文献   

环境整治与农业经营矛盾中的农户行为和行政调控——基于日本佐渡岛农户调查   总被引：1，自引：0，他引：1  

王岱  张文忠  余建辉 《地理研究》2011,30(9):1725-1735

随着我国经济的高速发展,生态环境问题越来越突出。在推进国内区域研究的同时,从微观的角度,研究发达国家面临的促进持续发展和保护环境的实际问题对完善我国区域发展理论和施政思路意义重大。本研究基于2006～2008年在日本佐渡岛的实地调研和深度访谈,揭示了政府推进朱鹳野生环境治理的过程中,农户农业经营条件的恶化以及农户的意识...  相似文献