Invisible institutions in emergencies: Evacuating the remote Indigenous community of Warruwi,Northern Territory Australia,from Cyclone Monica

Tropical Cyclone Monica is one of the most intense Australian cyclones in recorded history, and threatened several Indigenous communities in April 2006. It prompted the evacuation of the remote island community of Warruwi, and caused considerable damage to the mainland township of Maningrida. The evacuation of Warruwi went smoothly as emergency services personnel, the community and the airline cooperated to airlift some 350 people to designated safe areas on the mainland. We show that local institutions culturally embedded in Indigenous ways of understanding and responding to the world were important in providing essential but ‘unofficial’ services during the emergency. Recognizing and respecting the resilience of the local process involved in everyday Indigenous life is revealed as central to ensuring local cooperation and effective involvement of state and national institutions in delivering effective measures during emergencies. Ensuring that local, state and national authorities offer recognition and understanding of these Indigenous institutions, and develop strong relationships with them, should be a priority in developing approaches that limit conflict and trauma where emergency services risk overriding local protocol.     

Variability in the identification and enumeration of marine benthic invertebrate samples and its effect on benthic assessment measures

Studies designed to measure anthropogenic impacts on marine benthic communities depend on the ability of taxonomists to consistently discriminate, identify, and count benthic organisms. To quantify errors and discrepancies in identification and enumeration, 20 samples were completely reprocessed by another one of four participating laboratories. Errors were detected in 13.0% of the data records, affecting total abundance by 2.1%, numbers of taxa by 3.4%, and identification accuracy by 4.7%. Paired t-tests were used to test for differences in the Benthic Response Index (BRI), total abundance, numbers of taxa, and the Shannon-Wiener index between the original and the reanalysis data. Differences in the BRI were statistically insignificant. Although statistically significant differences were observed for numbers of taxa, total abundance, and the Shannon-Wiener index, the differences were small in comparison to the magnitude of differences typically observed between anthropogenically affected and reference sites.     

Spatial scales and probability based sampling in determining levels of benthic community degradation in the Chesapeake Bay

The extent of degradation of benthic communities of the Chesapeake Bay was determined by applying a previously developed benthic index of biotic integrity at three spatial scales. Allocation of sampling was probability-based allowing areal estimates of degradation with known confidence intervals. The three spatial scales were: (1) the tidal Chesapeake Bay; (2) the Elizabeth River watershed; and (3) two small tidal creeks within the Southern Branch of the Elizabeth River that are part of a sediment contaminant remediation effort. The areas covered varied from 10^–1 to 10⁴ km² and all were sampled in 1999. The Chesapeake Bay was divided into ten strata, the Elizabeth River into five strata and each of the two tidal creeks was a single stratum. The determination of the number and size of strata was based upon consideration of both managerially useful units for restoration and limitations of funding. Within each stratum 25 random locations were sampled for benthic community condition. In 1999 the percent of the benthos with poor benthic community condition for the entire Chesapeake Bay was 47% and varied from 20% at the mouth of the Bay to 72% in the Potomac River. The estimated area of benthos with poor benthic community condition for the Elizabeth River was 64% and varied from 52–92%. Both small tidal creeks had estimates of 76% of poor benthic community condition. These kinds of estimates allow environmental managers to better direct restoration efforts and evaluate progress towards restoration. Patterns of benthic community condition at smaller spatial scales may not be correctly inferred from larger spatial scales. Comparisons of patterns in benthic community condition across spatial scales, and between combinations of strata, must be cautiously interpreted.     

The ecological condition of Gulf of Mexico resources from Perdido Key to Port St. Joe, Florida: Part II near-shelf coastal resources

In 1999, the United States Environmental Protection Agency Gulf Ecology Division initiated a pilot study to assess the condition of nearshore coastal resources. Near-shelf areas associated with coastal beaches are susceptible to land based activities, but are not consistently monitored. Additionally, few or no marine water quality criteria exist for evaluating these waters. The goal of this pilot study was to assess the ecological condition of Gulf of Mexico near-shelf resources using a probability-based survey design. Data are used to generate a baseline assessment of condition in coastal nearshore areas and provide a comparative tool for evaluating future trends in condition. Water quality, sediment quality and benthic diversity data can provide a baseline assessment for managers to evaluate the potential for future problems such as nutrient over-enrichment, sediment contamination and degraded biological condition. We present results from a probability-based survey demonstration assessing near-shelf resources along the Florida panhandle.     

城市和农村社区防灾减灾手册和挂图的设计与编制

介绍了城市和农村社区防灾减灾手册和挂图的设计和编制,包括设计和编制原则、编制流程、手册和挂图的内容与结构、挂图编制的主要表示方法以及编制的组织和实施过程。     

A Constant Erosion Rate Model for Fine Sediment in the York River,Virginia

Results of field experiments using the Virginia Institute of Marine Science' Sea Carousel and tripod system reveal a highly dynamic sediment activity at the Clay Bank site in the York River. At the water-sediment interface, the critical bed shear stress for sediment erosion varied between 0.026 Pa and 0.1 Pa. For the well consolidated sediment below the interface, the critical bed shear stress increased significantly, to more than 0.6 Pa. The seasonal variation of erosion rate for the surficial sediment is significant. For the well consolidated sediment below the surficial sediment, however, the seasonal variation diminished and erosion rate approached a constant. Experimental results from the Carousel deployments imply that the erosion process for quasi-steady tidal flows is always near equilibrium. For this reason, a constant rate erosion model is proposed for the time during tidal acceleration phases. For other times, the erosion rate would be zero. The measured suspended sediment concentration at 10 cm above bed from the VIMS tripod system also Supports this model.     

COMPARISON OF FOUR ARTIFICIAL SUBSTRATES AND THE PONAR GRAB FOR BENTHIC INVERTEBRATE COLLECTION1

ABSTRACT: Four different bottom-placed artificial substrates were compared with the Ponar grab for collecting benthic invertebrates. Artificial substrate samples of organisms were larger and more diverse than those of the grab. Barbeque Basket samplers caught the most taxa and individuals and Beak Trays caught the least. Chironomids and crustaceans were dominant in artificial substrate samples. Exposure habitat (left or right bank) determined taxa availability, whereas sampler design determined suitability for colonization by the taxa. Diversity for Beak Tray samples was lower than that for other artificial substrates but higher than for Ponar samples. The Barbeque Basket, Bull Basket, and Multiple Plate samples were taxonomically similar. Ponar samples were different, and Beak Trays were of intermediate similarity. As qualitative samplers, Barbeque Baskets were 63 percent efficient, followed by Bull Baskets (55 percent), Multiple Plates (48 percent), Beak Trays (38 percent), and Ponar Grabs (6–10 percent). Bull Baskets required the least and Beak Trays the most replicates to be within a preselected percentage error of the mean at the 95 percent probability level for numbers of taxa and individuals, and for diversity. Under conditions of the study, Bull Baskets ranked highest, followed by Barbeque Baskets and Multiple Plates, in selected performance criteria. Differences between grab and artificial substrate samples are explainable in terms of major riverine habitats and characteristics of the collection methods.     

曝气位置对铁碳-沸石人工湿地污染物去除和温室气体排放的影响及微生物群落分析

为探究曝气位置与铁碳-沸石填充体积比对人工湿地污水净化及温室气体排放的影响,根据曝气位置和铁碳-沸石填料体积比不同构建了8个人工湿地,其中全程曝气处理分别为：F8T2(80%沸石+20%铁碳)、F6T4(60%沸石+40%铁碳)、F4T6(40%沸石+60%铁碳)、以及对照组F(100%沸石);半程曝气人工湿地分别对应为：F8T2-P、F6T4-P、F4T6-P和F-P。对人工湿地系统出水水质、温室气体和微生物群落进行分析测定。结果表明,与全程曝气相比,半程曝气显著提升了各人工湿地上层水中DO的含量(P<0.05),COD和NO₃⁻-N去除率均达到94.5%以上,F8T2-P、F6T4-P和F4T6-P出水中NH₄⁺-N平均质量浓度分别显著降低了50.40%、54.18%和51.00%(P<0.05)。曝气位置对铁碳-沸石人工湿地CH₄排放影响并不显著,但显著减少了N₂O的排放(P<0.05)。相较于全程曝气人工湿地,F8T2-P、F6T4-P和F4T6-P中N₂O排放通量分别显著降低了44.03%、35.62%和44.54%(P<0.05)。添加铁碳增加了pmoA、nosZ、nirS和nirK基因丰度,降低了mcrA基因丰度,这些基因与反硝化过程和温室气体排放有关;同时,F8T2-P、F6T4-P和F4T6-P中优势菌属Micropruina、Propionicicella、Nitrospria、Thauera、Denitratisoma、Dechloromonas有利于硝化和反硝化反应的进行。半程曝气且铁碳与沸石体积比为2:8的人工湿地,具备最佳的污染物去除和温室气体减排潜能。