建筑物变形监测设计与实施

通过对某一家属楼现状的分析,介绍了变形监测的设计思路和实施过程,为施工单位提供准确的观测成果,有利于施工单位采取相应措施确保该栋家属楼的安全。可以为类似工程变形监测提供参考。     

The wreck of the MV Rena: spatio-temporal analysis of ship-derived contaminants in the sediments and fauna of Astrolabe Reef

ABSTRACT

The October 2011 sinking of the container ship MV Rena on Astrolabe Reef, New Zealand, provided a rare opportunity to examine the fate of shipwreck-derived contaminants on an offshore rocky reef and food chain. Analyses of trace metals, polycyclic aromatic hydrocarbons (PAHs) and organotins indicated significant but localised contamination of Astrolabe Reef but not of nearby Mōtītī Island. Three years after the grounding, PAH concentrations were greater in sediments at Astrolabe (up to 131?mg kg^?1) than at control locations, while organotins from the ship's antifouling hull paint were found exclusively in Astrolabe Reef sediments and biota. Over 80% of Astrolabe sediment samples contained tributyltin at concentrations above guideline sediment levels (>0.07?mg kg^?1). Tributyltin and its decomposition products were also recorded in sea urchins, gastropods, lobster and fishes at concentrations up to 0.2?mg kg^?1. Wreck and cargo-derived metals, particularly copper, tin and zinc, were present in some Astrolabe sediment samples above Australia and New Zealand Environment and Conservation Council guideline concentrations. However, there appeared to be only limited transmission of metals through the food chain. Copper, tin and zinc were recorded at greater concentrations in Astrolabe sea urchins and gastropods compared to control specimens, while metal concentrations in other biota were comparable across impact and control sites. Despite over 3 years having passed since the Rena grounding, the data series does not show any upward or downward trends in contaminant concentrations on Astrolabe Reef. Consequently, there is uncertainty about the long-term implications of the Rena grounding for the ecology of Astrolabe Reef.     

Macroinvertebrate community structure and feeding interactions along a pollution gradient in Gilgel Gibe watershed,Ethiopia: Implications for biomonitoring

Feeding interactions among functional feeding groups (FFGs) of macroinvertebrates are robust indicators of aquatic ecosystem interactions. They provide information regarding organic matter processing, habitat condition and trophic dynamics. In tropical rivers with pronounced wet and dry seasons, macroinvertebrate based ecological monitoring tools are explicitly focused on metrics and indices, while ignoring interactions of FFGs. Therefore, the objective of this study was to investigate the functional feeding type metrics, diversity indices and feeding interactions among FFGs of macroinvertebrates along the water pollution gradient in Gilgel Gibe watershed, Ethiopia. Water quality parameters and macroinvertebrate community attributes were assessed for samples collected from upstream sites (15 sites), urban-impacted stretches (12 sites) and wetland-affected river zones (7 sites) of the watershed during the rainy (July) and dry (February) seasons. To understand the effect of pollution on the feeding interactions, stable carbon and nitrogen isotopes were analyzed. Macroinvertebrate-based diversity indices and functional feeding type metric showed deterioration of ecological integrity at the urban-impacted sites and substantial recovery in the wetland-affected downstream sites. Omnivorous feeding behavior of macroinvertebrates was noted for the upstream sites, whereas clear trophic guilds of FFGs were suggested for the wetland-affected river zones by the stable isotope results. The results of pollution gradient analysis and feeding interactions among FFGs revealed that the urban-impacted sites showed weaker interactions when compared to upstream and wetland influenced sites. This affirms the potential importance of feeding interactions among FFGs of macroinvertebrates in water quality monitoring.     

Groundwater monitoring strategies for variable contaminant migration boundaries

Abstract

Detection efficiencies of alternative groundwater monitoring networks were evaluated in relation to distance to a buffer zone (contaminant migration) boundary. This boundary establishes a distance limit within which contaminant plumes should pass through monitoring wells, located on curvilinear segments (monitoring loci) near a waste storage facility. Alternative strategies allocated monitoring wells to loci at specified distances, measured parallel to groundwater flow, from the downgradient boundaries of a landfill. One approach constrained wells to equal spacing, measured perpendicular to groundwater flow. Compressing well locations 10% closer to the downgradient corner of the landfill rendered alternative monitoring configurations. Computations by a monitoring efficiency model indicated: (a) networks largely maintained detection efficiency for different contaminant migration boundaries; (b) one network most efficiently attained a target detection capability for all contaminant migration boundaries; and (c) compressed networks slightly outperformed equal-spaced counterparts. Compressed networks with more wells along closer monitoring loci best maintained the detection efficiency when shifting the contaminant migration boundary closer to the landfill. Procedures described in this paper may be useful for examining trade-offs between monitoring efficiency and distance limits of contaminant travel at landfills posing potential hazards to underlying groundwater.     

WiMAX技术及其在地震监测系统中的应用探讨

基于IEEES02．16标准的WiMAX技术是一种宽带无线接人技术。本文分析了WiMAX技术的特点,并结合地震监测行业的需求,论证了WiMAX技术应用于地震监测系统的可行性,并给出了具体的应用方案,指出了实际应用中存在的难点和问题。     

海潮负荷对沿海地区宽幅InSAR形变监测的影响

海岸带地区是全球自然生态环境最为复杂和脆弱的地域之一,合成孔径雷达干涉测量（InSAR）技术可以为全球人类活动、气候变暖和俯冲带剧烈构造运动等背景下的大范围海岸带地理环境变化研究提供重要观测资料.海洋潮汐导致固体地球长周期形变,波长尺度为10²~10³ km的海潮负荷引入mm级至cm级的形变梯度,此类非构造信号对海岸带InSAR精密形变分析（如：大范围、微小、缓慢且非稳态构造过程等）造成显著影响.本文以宽幅模式SAR数据为例,基于多种海潮模型研究了全球典型海岸带地区（福建、智利和阿拉斯加湾）海潮负荷效应对宽幅InSAR形变监测的影响,给出了宽幅InSAR海潮负荷三维分量估计与差分相位提取方法,并进一步讨论了基于不同海潮模型估计海潮负荷位移的差异.海潮负荷影响不仅与研究范围大小有关,其形变梯度变化与研究区域地形特征存在强相关,对于长波长形变分析而言,传统平面或者曲面拟合方法难以有效分离海潮负荷位移.

     

Spatial and temporal variability of hard-bottom macrofauna in a disturbed coastal lagoon (Sacca di Goro, Po River Delta, Northwestern Adriatic Sea)

The sessile and mobile macrobenthos on artificial hard bottoms was studied in 12 stations of the Sacca di Goro lagoon, a brackish, highly stressed water basin in the delta of the river Po, open to the Northwestern Adriatic Sea. Three sampling surveys were carried out in June and September 2000 and June 2001 in order to make three types of temporal comparisons: (i) on a seasonal scale, before and after a summer dystrophic event; (ii) on an annual basis, before and after the works of excavation of a canal through the outer sand bank; (iii) on a multiannual scale, comparing the data with those of a survey carried out in 1988. The biocoenoses did not show large fluctuations after a moderately severe summer dystrophic crisis, while the digging of the canal caused clear changes in the macrobenthos community structure after one year. The long-term comparison showed a shift in the community patterns after a decade.     

Public participation in monitoring programmes as a tool for lakeshore monitoring: the example of Lake Pyhäjärvi, Karelia, Eastern Finland

Lake Pyhäjärvi, on the border between Finland and Russia in Karelia, is a very valuable clear-water lake of the Lobelia type. It belongs to the European Union's Natura 2000 programme in Finland, and has been included in regional and national monitoring programmes since the 1960s. The main monitoring station is situated near the outlet of the lake. Deterioration of its water quality was suspected already in the 1980s because of decreasing Secchi depths (transparency) and increasing chlorophyll a.The occurrence of algal blooms on the lakeshores is monitored weekly during each summer at one site on Lake Pyhäjärvi (site 1). This is a part of nationwide intensive algae monitoring programme organised by the environmental authorities together with voluntary observers at some 270 lake sites in Finland since 1998. Since 1997, Secchi depth observations have been carried out by volunteers biweekly or monthly at 17 sites on the lake. In the vicinity of one of these transparency observation sites (station 100), intensive monitoring of algae has been carried out. At this lakeshore monitoring site 69 algal observations were made, ten of which recorded algal blooms during the study period 1998–2002. The observed algal blooms were caused by algae of the Anabaena species, mainly by Anabaena lemmermannii. At Lake Pyhäjärvi the number of algal bloom observations received from the public have decreased from the 1990s to the 2000s. The range of Secchi disc transparency was 5.0–8.4 m with a mean value of 6.2 m at station 100 and 4.3–7.7 m (mean 6.1 m) at the main monitoring station 2 during the open water periods in 1998–2002. During this study period, the maximum values at site 100 seem to have increased slightly, which might indicate some improvement in the water quality due to decreased point source loading.We conclude that the intensive algal monitoring results of 5 years at the lakeshore site and the transparency results — both compiled by trained volunteers — reflect an improvement in the state of Lake Pyhäjärvi in Karelia. This conclusion is in accordance with the long-term water quality and short-core studies of sedimentary diatoms in Lake Pyhäjärvi. We suggest that the intensive algal observations and transparency measurements are both suitable methods for the monitoring of lakeshores and lakes, and that both are suitable for voluntary monitoring. We found public participation a good tool for monitoring lakes and lakeshores.     

长江中下游湖泊群不同生活型水生植物分布的时空变化(1986—2020年)

不同生活型水生植物对水环境的影响和碳固持能力不同,开展大尺度范围内不同生活型水生植物的时空分布和动态变化研究,是全面掌握湖泊水生态环境变化趋势、准确核算水生生态系统碳源/碳汇的前提。以长江中下游10 km²以上(共131个)的湖泊为研究对象,基于野外调查和先验知识,通过光谱分析,研发了不同生活型水生植物遥感高精度机器学习识别算法,解析了长江中下游湖泊群不同生活型水生植物的时空变化规律。研究表明,长江中下游湖泊群不同生活型水生植物遥感监测精度为0.81,Kappa系数为0.74;1986—2020年长江中下游湖泊群水生植物面积为2541.58~4571.42 km²,占湖泊总面积的15.99%~28.77%,沉水植物是优势类型(Max_1995年=2649.21 km²,Min_2005年=921.38 km²),其次是挺水植物(Max_2005年=1779.44 km²,Min_2020年=569.05 km²)和浮叶植物(Max_2015年=685.68 km²,Min_2000年=293.04 km²);水生植物主要分布在长江干流流域湖泊群,其次是鄱阳湖流域、洞庭湖流域、太湖流域和汉江流域;变化趋势上,1986—2020年长江中下游湖泊群水生植物面积呈现先增长(1986—1995年)、后下降(1995—2010年)、再增加(2010年后)的趋势。本研究可为长江中下游湖泊群生态环境调查及水环境管理提供重要参考。     

宿迁地震台地震监测能力分析

根据宿迁地震台地震计和数采参数、台站背景噪声等数据,结合历史地震观测数据,运用统计学计算方法,计算宿迁地震台地震监测能力。结果认为:宿迁地震台短周期台基背景噪声较大,微小地震监测能力较弱,但基本可以监测到M_L 2.0地方震,也可监测到150 km范围内周边城市M_L 2.5地震。