The place of rural, remote and least-wealthy small islands in international water development: the nexus of geography–technology sustainability in Chuuk State, Federated States of Micronesia

Many least-wealthy, rural, remote and resource-poor small island communities are unlikely to benefit from high-profile global water improvement initiatives. Their small landmasses, geologic composition, geography, social and technological isolation, colonial history, and weak educational and financial resources constitute significant barriers to improving access to safe drinking water. This paper discusses the relatively unique position of such island societies in the international community, providing a case study of the Federated States of Micronesia that integrates data and information pertaining to water resources management and governance, spanning from the island village to national scale. A vision is offered regarding the interaction between small island human and biophysical water systems, manifesting ways to pursue water resource development to improve public health which are constructed to be economically, physically and culturally sustainable.     

Evaluation of the spatial changes in seagrass cover in the lagoons of Lakshadweep islands,India, using IRS LISS III satellite images

A study was conducted in Lakshadweep islands to determine the feasibility of using Indian Remote Sensing (IRS) satellites for detecting changes in the seagrass from other coastal features. IRS ID and IRS P6 LISS III having spatial resolution of 23.5 m with lower cost compared to all other contemporary satellites with the same spatial resolution have not been widely used for monitoring the changes in seagrass cover. In this context, the present study attempted to explore the effectiveness of LISS III data for mapping seagrasses and to inform the international community about the usefulness of these low-cost imageries for coastal resource monitoring. Supervised classification and change detection studies found a significant decrease in seagrass cover of 73.03 ha in the Lakshadweep group of islands. An overall accuracy of 67.5% was obtained for the change maps, and seagrass cover and its changes vary at different islands.     

《更路簿》及其南沙群岛古地名释义

《更路簿》是一本海南渔民往来南海诸岛礁的航海手册,记录了海南岛渔民命名南海岛礁的地理名称136处,这些南海地名生动地反映了南海岛礁的自然地理及文化特征。该文论述了《更路簿》与《针路簿》的起源与差别,探讨了《更路簿》中的岛礁分类与命名方式,将《更路簿》中的南沙岛礁的名称及其释义集成在一起,并对照谷歌地球进行定位与校核。依据名从主人的地名学规则,海南渔民是最早探索、发现、命名南海岛礁并对其不间断地开发的经营者,因此为南海诸岛是中国的固有领土提供有力佐证。该文从南海的季风洋流对航海的影响分析,探讨了帆船时代居住在季风海流两侧国家的人民探索发现南海诸岛的局限性。     

GPS RTK在海岛(礁)测量中的应用

本文简要介绍了GPS RTK技术在海岛(礁)测量中的基本原理,根据海岛(礁)地形的特点,探讨并实践GPS RTK测量海岛(礁)地形的具体方法和步骤,同时利用高精度全站仪对GPS RTK的测量精度进行评定,证明GPS RTK精度能够满足海岛(礁)地形测量的要求。     

被越南侵占的中国南沙群岛岛礁的时空分布特征及战略格局

以南海海域200 m等深线水深图和南沙群岛海域11幅1﹕250 000海图以及1﹕800 000海图为基础数据,使用ArcGIS 10.1,采用墨卡托投影,CGCS 2000坐标系对海图进行配准并进行矢量化处理,提取图中水深点、岛礁位置信息、礁坪、礁体位置信息。通过对被越南侵占的南沙群岛29座岛礁的空间分析,认为被占岛礁在空间上存在“一纵一横”的空间分布特征,南沙群岛被占岛礁南子岛、景宏岛、南威岛、六门礁从N至W构成了4个核心和广雅滩1个次核心的岛礁空间分布战略格局。通过对被占岛礁面积、礁坪面积及礁体面积进行插值处理,叠加分析,按重分类方法将插值结果按数值大小划分为5类,予以揭示被占岛礁的重要程度及未来开发潜力。通过分析越南侵占岛礁的岛屿面积与礁体面积比值,指出鸿庥岛、景宏岛、西礁、中礁、毕生礁、六门礁、柏礁有较大填海造陆潜力的岛礁。     

Vulnerable groups and preliminary insights into intersecting categories of identity in Laamu Atoll,Maldives

The notion of vulnerability has acquired a significant role in discussions around reducing risk and identifying vulnerable groups, which is particularly important for targeting risk‐reducing policy and practice. Through ten semi‐structured interviews with 24 stakeholders, this study collected local perceptions on the following groups considered most vulnerable in Laamu Atoll, Maldives: youth and children, women, the elderly, people with disabilities, displaced persons and migrants, and farmers. In doing this, the significance of intersecting categories of identity for understanding vulnerability emerged and was explored; an approach that is often absent or scarcely applied in studies that identify vulnerable groups in the Maldives and elsewhere. Intersections between location, youth and gender or disability, as well as gender and marital status emerged as relevant for the Laamu Atoll context. Although this study acknowledges the incompleteness of its intersectional analysis, these findings provide important preliminary insights into the role of intersectionality in shaping vulnerability experience. To enhance scholarship on vulnerability, future studies could further explore intersectionality in Laamu Atoll and the Maldives using this study as a base and also improve its practical applicability for policy and practice.     

受陆岸影响浅水区台风风浪的计算方案

在我国港口工程技术规范的波浪成长理论基础上，考虑到台风波浪的基本特点、等效水深的概念、浅水区波浪的折射、不规则波的能量分布特性、受陆岸和岛屿影响角度范围内的有效能量风区长度等因素，提出了受陆岸、岛屿影响浅水区（包括海湾区）台风风浪的计算方案。本方案只需台风中心位置、中心气压和计算点于各方位的风区长度（受陆岸影响部分）等资料，便可快速地得到计算点的波浪要素。经实测资料验证，效果良好。     

龙口湾水动力特征及其对人工岛群建设的响应

基于龙口湾及附近海域的水文实测资料,利用Mike21数学模型模拟了人工岛建设前后的潮流、波浪、纳潮量及水交换率等水动力特征,探讨了人工岛群建设对龙口湾水动力环境的影响。结果表明,人工岛建设显著改变了龙口湾潮流场特征及水体运动路径,湾内受到人工岛的阻挡,流速普遍减小,局部区域潮流运动形式由往复流变为旋转流,流向变化较大,余流形成多个涡旋;湾外由于堤头挑流作用导致局部区域流速增大且余流流速增大,潮流运动形式未发生明显改变。受人工岛的掩蔽作用,人工岛及附近区域的波浪有效波高普遍减小。龙口湾潮位出现北部最大潮差变小、南部最大潮差增大的格局,壅水作用导致人工岛内部水道潮差变化明显。人工岛建设直接占据了龙口湾海域面积,导致其纳潮量明显减小,水交换率呈现南部和北部增大、人工岛北侧以及内部水道减小的特征,人工岛造成的水动力环境的改变是影响水交换率变化的主要原因。人工岛群建设导致龙口湾内的潮流、波浪、纳潮量以及水交换等水动力特征减弱,是引起龙口湾水动力条件变化的根本因素。     

大陆岛入海沉积物通量的估算研究

大陆岛入海沉积物通量（Q_s）信息对于精确解译大陆架沉积记录的研究是个重要补充。针对如何估算大陆岛Q_s的科学问题,本文以中国东南部海域的8 227个大陆岛为例,提出了一种基于邻近大陆中小型河流Q_s的经验公式计算大陆岛Q_s的解决方案。该方案在实施时需设置两个假定,即大陆岛的Q_s法则遵循邻近大陆中小河流的Q_s法则和可将1个大陆岛当作1个河流流域计算其Q_s。结果表明：（1）经验公式计算的大陆岛Q_s为其最小估计值;如考虑大陆岛流域的具体情况,实际的Q_s值会稍微增加,但其增幅不超过n^0.13（n为流域数量）;（2）经验公式能获取大陆岛Q_s的大致数量级信息;大陆岛的总面积为4 418.49 km²,对应Q_s的数量级为10⁶ t/a,与邻近大陆中型河流入海通量的数量级相当;（3）在大河河口湾充填阶段完成以前,大陆岛沉积物是内陆架泥质沉积体的主要物源之一。因此,大陆岛入海沉积物会对大陆架沉积体系的形成和演化造成一定程度的影响,需引起研究人员的高度重视。     

黄河三角洲北部贝壳堤岛的近期演变

通过不同年代地形图、卫星影像的对比及野外实地测量等,综合分析了黄河三角洲北部开敞型和潮沟型两类贝壳堤岛近50年来的数量和面积变化及其演化特征。结果表明,该区两类贝壳堤岛自20世纪50年代以来在自然和人为因素的共同作用下发生了明显的变化,但其演化特征因岛屿成因的类型差异而各不相同。目前,该区贝壳堤岛群逐渐萎缩,人类活动已成为影响三角洲北部两类贝壳堤岛发育演变的主导因素,特别是潮沟型贝壳堤岛,基本上结束了自然演化的历史,呈现出新的演化特征。