对IPCC第五次评估报告中有关淡水资源相关结论的解读

IPCC第五次评估报告指出,与淡水资源相关的气候变化风险随着温室气体浓度增加而显著增加。气候变化已经导致区域降水发生显著变化;多年冻土、冰川持续萎缩,积雪不断减少;降雪区春季最大径流量逐渐提前,夏季干旱不断加剧。预估结果表明：21世纪温室气体排放将加剧淡水资源相关风险。如显著减少亚热带干旱地区的地表水和地下水资源,加剧行业之间用水竞争;极端事件（如极端降水）明显影响原水水质,威胁用水安全;气候变化同时将导致农业灌溉用水量增加、能源生产效率降低等不利影响。报告指出需采取硬性基础设施建设和软性制度措施建设相结合的适应措施,加强水资源管理,克服气候变化的负面影响,减少损失。     

1982-2016年北极开阔水域变化

近30年来,北极海冰覆盖范围大幅缩减,开阔水域也相应地发生显著变化。本文利用美国雪冰中心的海冰密集度产品以及美国海洋和大气科学管理局的海水表面温度数据产品,分析了1982-2016年北极开阔水域面积以及开阔水域季节长度的年际变化,并进一步探讨了海水表面温度对开阔水域时空变化的影响。结果表明北极开阔水域面积平均每年增加55.89×103 km2,海冰消退时间以平均0.77 d/a的速度在提前,海冰出现时间以平均0.82 d/a的速度在延迟,导致开阔水域季节长度以平均1.59 d/a的速度在增加。2016年达到了有遥感观测资料以来开阔水域面积和开阔水域季节长度的最大值,分别为13.52×106 km2和182 d。9个海区的开阔水域变化特征有一定的差异,对开阔水域变化贡献最大的有北冰洋核心区、喀拉海和巴伦支海。海水表面温度对开阔水域的变化有着重要影响,且影响的程度与纬度相关,即高纬度地区的海水表面温度对开阔水域的影响高于低纬度地区。     

2008年夏季加拿大海盆永久冰区的淡水累积现象

A combination of δ~(18)O and salinity data was employed to explore the freshwater balance in the Canada Basin in summer 2008.The Arctic river water and Pacific river water were quantitatively distinguished by using different saline end-members.The fractions of total river water,including the Arctic and Pacific river water,were high in the upper 50 m and decreased with depth as well as increasing latitude.In contrast,the fraction of Pacific river water increased gradually with depth but decreased toward north.The inventory of total river water in the Canada Basin was higher than other arctic seas,indicating that Canada Basin was a main storage region for river water in the Arctic Ocean.The fraction of Arctic river water was higher than Pacific river water in the upper 50 m while the opposite was true below 50 m.As a result,the inventories of Pacific river water were higher than those of Arctic river water,demonstrating that the Pacific inflow through the Bering Strait is the main source of freshwater in the Canada Basin.Both the river water and sea-ice melted water in the permanent ice zone were more abundant than those in the region with sea-ice just melted.The fractions of total river water,Arctic river water,Pacific river water increased northward to the north of 82°N,indicating an additional source of river water in the permanent ice zone of the northern Canada Basin.A possible reason for the extra river water in the permanent ice zone is the lateral advection of shelf waters by the Trans-Polar Drift.The penetration depth of sea-ice melted waters was less than 30 m in the southern Canada Basin,while it extended to 125 m in the northern Canada Basin.The inventory of seaice melted water suggested that sea-ice melted waters were also accumulated in the permanent ice zone,attributing to the trap of earlier melted waters in the permanent ice zone via the Beaufort Gyre.     

我国海水冷却技术应用研究

海水循环冷却技术因其环保和节水特点已成为海水冷却技术的发展方向。文章分别介绍直流冷却和循环冷却2种海水冷却技术,并对二者的优劣势进行比较;阐述2种海水冷却技术在国内外的应用现状,分析我国在海水冷却技术应用中存在的影响海洋环境、采用技术与需求不符、技术研发不足和监管标准亟待建立等主要问题;在此基础上提出对策建议,主要包括推进循环冷却技术产业化应用、加强标准体系建设、提高技术环保水平和转变技术应用观念,以期为我国海水冷却技术的健康发展提供参考。     

Bloom forming species of phytoplankton in two coastal waters in the Southeast coast of India

The results of an investigation carried out during June 2005 to May 2007 on bloom-forming phytoplankton species composition and abundance in the Parangipettai and Coleroon coastal waters(Southeast coast of India) are reported.Air and surface water temperatures(℃) varied from 25.1 to 30.1 and 24.5 to 28.5,respectively,in the former waters and from 25.5 to 31.2 and 25.0 to 29.3 in the latter waters.The respective salinities varied from 6.0 to 28.5 and 5.0 to 33.1 and the respective pH ranged between 7.0 and 8.3 and 7.2 and 8.3.Correspondingly,the dissolved oxygen content varied from 3.1 to 7.5 and 3.1 to 7.9 mgL-1 while the light extinction coefficient(LEC) values ranged between 3.1 and 10.1 and 1.8 and 11.0.The content ranges of inorganic nutrients,i.e.,nitrate,nitrite,phosphate and silicate(μmolL-1),in the Parangipettai and Coleroon coastal waters were:6.5-27.0;1.0-8.9;0.1-3.0 and 15.0-140 and 10.1-23.4;1.2-8.9;0.2-3.1 and 55-125 respectively.The chlorophyll a contents in both waters ranged from 2.0-7.5 μgL-1.Presently,124 phytoplankton species representing different classes were recorded in the Coleroon coast,viz,Bacillariophyceae(77);Dinophyceae(19);Cyanophyceae(15);Chlorophyceae(10) and Chrysophyceae(3),whereas 117 phytoplankton species were recorded in the Parangipettai coast,viz,Bacillariophyceae(66);Dinophyceae(22);Cyanophyceae(19);Chlorophyceae(7) and Chrysophyceae(3).The phytoplankton cell abundance in the Parangipettai and Coleroon coastal waters varied from 290 to 111662 and 140 to 132 757 cells L-1,respectively,with peak diversity(3.38 and 3.52 bits ind-1.) recorded in summer.The maximum abundance occurred in summer coinciding with the stable hydrographical conditions.The seasonal distribution and abundance of phytoplankton are discussed in relation to hydrographical parameters.Totally 31 and 24 species of phytoplankton were found to be bloom-forming in the Parangipettai and Coleroon coastal waters,respectively.Presently Trichodesmium bloom was also observed,which appeared at the 10 fathom level of the coastal water and quickly spread to the marine zone of the Vellar estuary and near the mouth region of the mangrove waters.The Parangipettai and Coleroon coastal waters are subject to long term fluctuations in physico-chemical conditions depending upon the seasonal tidal range and freshwater influx,resulting in a continuous exchange of organic,inorganic,plant and animal matters.     

淡水有核珍珠大面积养殖技术研究

在33.3hm2的育珠水体中,选择2龄三角帆蚌作手术贝,采用外套膜错位排列的方法,每只母蚌植入直径6～7mm珠核10粒进行育珠试验。结果表明,经2～3a的育珠,育珠蚌成活率75%,留核率45%～75%,优质珠率40%,经济效益是普通无核珍珠的3倍以上,并且收珠后的育珠蚌可以再次植核育珠。1991-2001年,试验结果以广东绍河珍珠有限公司建立的养殖基地在福建、江西、安徽、浙江和江苏等地进行示范和推广,推广面积2000hm2,取得良好的经济效益和社会效益。     

盐扩散法水文测井在焦家金矿床深部详查中的应用

盐扩散法水文测井属地球物理勘探方法,在焦家金矿床深部详查中取得了很好的效果。该文简要说明了盐扩散法水文测井的基本原理,详细介绍了盐扩散法水文测井的工作步骤,系统总结了盐扩散法水文测井的异常规律,根据加盐水前后流体电阻率的变化,判断出水位置、水的补给方向及淡水或咸水。     

最经济的取水方式：海底开采淡水——大海深处有甘泉

淡水资源的短缺一直都是国际环境专家、科学家与政治家最为关心的话题之一。根据联合周的一项统计,目前全球还有10亿人缺少干净的饮用水,而每天多达6000人因为缺水而死亡,其中大部分是儿童。科学家通过最新技术证实海底之下蕴藏着丰富的淡水资源。美国和欧洲科学家都在酝酿设计开发巨型钻探装置,以便深入海底之下抽取淡水,缓解全球日益严峻的水资源危机。     

珊瑚礁岛屿淡水透镜体研究综述

淡水透镜体是珊瑚礁岛屿上重要的地下淡水资源,对于满足人们的日常生活需要和维护珊瑚礁岛屿的生态系统非常关键。文章回顾了国内外珊瑚礁岛屿淡水透镜体的研究历程,介绍了它的理论和特征,综述了其发育和演化与岛屿的水文地质、气候、潮汐、地形和植被等的关系。另外,自然压力,诸如干旱、海水入侵、海平面升高和岛的机械侵蚀等,以及人为压力,如过多抽取淡水、污染、地形改变和海岸工程等,都对珊瑚礁岛屿淡水透镜体的稳定造成了威胁,对这类干扰方面的研究也有很多。文章还介绍了常用的淡水透镜体研究模型,包括物理模型、解析模型和数学模型,并对其在淡水透镜体中的研究应用作了概述。对中国珊瑚礁岛屿淡水透镜体的研究现状也作了介绍,研究涉及西沙群岛永兴岛珊瑚礁淡水透镜体的厚度、抽取地下水导致的倒锥现象和生物修复等方面。最后,文章对南海珊瑚礁岛屿淡水透镜体的研究作出展望,提出开展对南海其他珊瑚礁岛屿淡水透镜体的研究工作,以及如何使抽取的地下水除污并可供饮用。