干旱监测与评价技术的发展及其科学挑战

由于气候变暖及人类活动加剧,干旱灾害对全球粮食、水资源和生态安全及人类可持续发展的威胁日益突出,对干旱决策服务和应急管理能力提出了严峻挑战,干旱监测预警、影响评估及应急管理等方面的技术水平亟待进一步提高.在系统总结以往研究成果基础上,阐述了对干旱气候、干旱和干旱灾害的科学认识,归纳了干旱气候、干旱和干旱灾害的成因及其主...     

Ways of investigating radionuclide migration processes in the lithosphere and hydrosphere

In Russia, until recently, it was considered that groundwater was protected from surface radioactive contamination by soil and rocks in the zone aeration. Groundwater was not a subject of radiation control. The accident at the Chernobyl Nuclear Power Plant showed, however, that groundwater is vulnerable to radioactive contamination. In this connection, the vulnerability of groundwater to and the problems of protecting groundwater from radioactive contamination became urgent. The assessment of natural protection of groundwater from radioactive contamination is now considered a top priority. The zone of aeration is generally considered to be the zone separating groundwater from surface contamination. In respect to radioactive contamination, soils that may fix a large quantity of radionuclides serve as a protection zone of a higher order. The mapping of protectibility was done for each radionuclide taking into consideration the specific structure of the flow medium and migration properties of a radionuclide.⁹⁰Sr and¹³⁷Cs have different mechanisms of transport; convective transport is characteristic of the former and diffusive transfer of the latter. This is conditioned by different physico-chemical properties of the radionuclides and principally by their sorption capacities. The coefficient of distribution of⁹⁰Sr is in many times less than the coefficient of distribution of¹³⁷Cs. The environmental protection problem in regions with nuclear power plants and in areas subjected to radioactive contamination may be solved using a monitoring, system including interrelated systems of observation and prediction of the lithosphere and the hydrosphere. The problem of mathematical modeling of migration processes is related to the complexities of modeling the processes of flow, mass transfer, and the accompanying physicochemical processes in zones of full and partial saturation, as well as difficulties in mathematical calculations.     

气候变暖条件下,中(高)亚洲地区不稳定型冻土的巨大挑战和创新解决方案:——来自首届亚洲冻土大会及会后青藏高原考察的总结报告

首届亚洲冻土大会于2006年8月5~16日在兰州、青藏线和拉萨顺利召开.大会讨论主要包括以下5个议题:1)冻土工程;2)山区和高原冻融灾害及冰缘环境;3)冰冻圈的气候与环境条件;4)冻土水文、寒区水资源及土地利用,和;5)冻土监测、制图及模拟.国内论文大多集中于青藏铁路各种科技创新和工程(示范)建设方面.中亚冻土分类、制图和监测研讨会明确了制定统一的中亚地区冻土图的计划和实施方案.会议期间,国内主要新闻媒体对全球15位著名冻土学家进行了联合采访.大约80位中外代表参加了青藏(公)铁路沿线考察,并于8月15日在拉萨举行青藏铁路工程和环境问题讨论会.专家一致认为,青藏铁路所采取的冻土工程措施基本上是恰当、有效的,能够保证青藏铁路路基的长期稳定性.但是,沿线寒区环境保护问题还任重道远,需要尽快进行综合管(治)理,以达到青藏地区社会经济和谐、持续发展的目标.     

Butyltin concentrations along the Japanese coast from 1997 to 1999 monitored by Caprella spp. (Crustacea: Amphipoda)

The concentrations of butyltins along the Japanese coastline were investigated from 1997 to 1999, 7 to 9 years after implementation of legislation limiting the use of tributyltin (TBT) in Japan. Seawater was sampled at 0.5 m depth, and Caprella spp. were collected from Sargassum spp. and aquaculture facilities from 18 areas within four broad areas along the coastline of Japan, i.e., the Pacific coast of northern Japan, the coast along the Sea of Japan, Tokyo Bay and adjacent areas, and western Japan. Butyltins (MBT, DBT and TBT) were detected in 32 of the 63 seawater samples with average concentrations of 4.6 ng MBT/l, 4.5 ng DBT/l and 6.8 ng TBT/l, respectively. Butyltin concentrations in seawater from western Japan indicate "hot spots" even in unpopulated areas. Butyltins (MBT, DBT and TBT) were detected in all samples of Caprella spp., varying from 2.3 ng BTs /g wet wt in C. penantis R-type from Tobishima Island in the Sea of Japan to 464 ng BTs /g wet wt in C. decipiens Mayer from Amakusa, western Kyushu. The BT concentrations in Caprella spp. form western Japan were significantly higher than those from other areas, including Tokyo Bay and adjacent areas, where large scale industry and international ports are located. These results indicate that butyltin contamination still remains even in unpopulated areas after the regulation on TBT usage, and that the regulation governing TBT usage since 1990 has not been effective enough to concede recovery of shallow water ecosystems around Japan.     

森林火灾后生态变化遥感监测评价模型的构建方法研究

通过攀西林区云南松林的一系列旧火烧迹地的更新恢复和生态变化的遥感调查，对各生态因子的空间分布特征及生态变化的影响规律进行分析，确定了评价因子（变量）及其评价标准，利用遥感信息，以及地形、土壤、林分和林木受害程度等要素的８个因子的模糊综合评判结果和火烧年限等为变量，通过多组数据的多元统计分析，建成森林火灾后生态变化遥感监测评价模型，经野外调查结果验证分析，达到了预期的攻关目标。为使该模型能适应森林生态遥感监测运行系统的需要，对各监测因子数据的获取、植被指数的提取等方面进行了深入的方法探索。     

鲅鱼圈港倾废区疏浚污染物的时空分布和运移规律

本文依据营口鲅鱼圈港倾废区８个航次的疏浚物监测和追踪调查数据，深入了解了倾废海区中悬浮物、浊度、ＣＯＤ和ｐＨ等指标随潮汐变化的时空分布规律。调查结果表明：虽然该倾废区实施疏浚物倾倒已达４ａ，但该区中除悬浮物含量略有增加外，其他指标（如ＣＯＤ，ＤＯ，ｐＨ等）基本处于一类海水正常值范围。疏浚物倾倒后２０ｍｉｎ内可引起水中悬浮物和浊度含量的急剧上升，对海水的ｐＨ和ＣＯＤ含量也有一定程度的影响．表面浑水团主要随表层流和风向运移，悬浮物和浊度降至海区背景浓度的时间约需３５～４５ｍｉｎ，迁移距离可达１．３ｎｍｉｌｅ，影响面积通常可达０．３ｋｍ２．     

Monitoring benthic biodiversity restoration in Lyme Bay marine protected area: Design,sampling and analysis

Long-standing concerns about the effects of scallop dredging and demersal trawling on high diversity mudstone reef and cobble habitats in Lyme Bay, southwest England, were addressed by the exclusion of bottom towed fishing gear from a 206 km² area in July 2008. A consortium led by Plymouth University Marine Institute was funded by the UK Department of Environment, Food and Rural Affairs to design and implement a study (initially funded for 3 years) to examine the effects of the closure on both nekton and epibenthos. This paper provides a detailed account of the methodology employed from survey design to data analysis to provide a protocol for future MPA monitoring programmes. Information on historical fishing effort, substrate distributions and current and previous closure boundaries was overlaid using GIS to locate suitable monitoring sites. Non-destructive and cost-effective techniques, including a towed high-definition video array and static baited video, were used to quantify changes in relative abundances of epibenthos and nekton over three years at sites previously fished but now closed to bottom towed fishing compared to both fished and un-fished reference sites. The monitoring programme as described provides a model for robust, cost-effective evaluation of the efficacy of policy instruments for feedback into the adaptive management cycle.     

大亚湾生态监控区的浮游植物年际变化

依据国家海洋局、国家海洋局第三海洋研究所等权威机构2004~2007年所获的数据和资料,对大亚湾生态监控区近4a长时间尺度的浮游植物群落年际变化进行分析,通过物种组成、丰度变化、优势类群演替、群落结构及赤潮灾害事件来反映生境的退化,探讨其变化的主要原因及趋势。结果表明,浮游植物群落由暖水种占绝对优势转变为广温广布种占主导地位。种类与丰度呈逐年下降的态势,浮游植物丰度的分布保持西高东低,近岸高于远岸的特征,浮游植物的高丰度与营养盐丰富及温排水有关。终年以硅藻为优势种群,优势种演替具有明显的季节与年际变化,细长翼根管藻(Rhizosolenia alataf.gracillima)是春季稳定的优势种,柔弱拟菱形藻(Pseudo-nitzschia delicatissma)是夏季稳定的优势种,春末甲藻的优势度增加明显。浮游植物群落多样性指数呈逐年下降趋势,均匀度呈逐年上升态势。浮游植物的异常增殖及过度集中导致多样性较低,种间比例不均匀,群落结构单一。赤潮季节性发生频繁,发生频率及引发种类呈上升趋势,海洋环境脆弱。