Method for Assessing Source Zone Natural Depletion at Chlorinated Aliphatic Spill Sites

This work focuses on the site‐specific assessment of source zone natural attenuation (SZNA) at chlorinated aliphatic hydrocarbon (CAH)‐impacted sites. The approach is similar in some ways, but different in other ways from recently proposed SZNA assessment paradigms for petroleum‐impacted sites. The similarities lie in the organization of the approach around determining: (1) whether or not SZNA is occurring, (2) the current SZNA rate, and (3) what is the future projection for SZNA rate changes and the final state of the source zone. Differences lie in how those rates are determined, especially with respect to the quantities measured and data reduction. Petroleum‐impacted site SZNA approaches emphasize quantifying fluxes of electron acceptors, while the proposed CAH assessment approach emphasizes quantifying parent and daughter compound fluxes. A paradigm for assessing SZNA at CAH sites is presented and its use is illustrated, for example former dry cleaner site, where the SZNA rate was approximately 3.5 kg/year as tetrachloroethylene (PCE) with about 80% of the mass loss attributed to groundwater flow and 20% attributed to vapor transport.     

Sabella spallanzanii filter-feeding on bacterial community: ecological implications and applications

The filtration process of Sabella spallanzanii Gmelin on bacterial community was studied in a coastal area of the Northern Ionian Sea (Mediterranean Sea) at three sites, S. Vito, Lido Gandoli and Lido Silvana, where some specimens of S. spallanzanii were transplanted. Analyses were performed both on water and worm samples. A total of six microbial groups were examined: culturable heterotrophic bacteria, total culturable bacteria at 37 degrees C, culturable vibrios, total and fecal coliforms and fecal streptococci. The bacterial densities were usually orders of magnitude higher in the worm homogenates than in the corresponding seawater and the highest values were observed in August. The ability of S. spallanzanii to accumulate the microbial pollution indicators suggests this species can be employed as a bioindicator for monitoring water quality. Moreover, the accumulation capability of S. spallanzanii for specific micro-organisms provides a potential role in sewage bioremediation.     

Nutrient limitation of heterotrophic bacteria in Florida Bay

We examined heterotrophic bacterial nutrient limitation at four sites in Florida Bay, U. S. in summer 1994 and winter 1995. Bacterial growth and biomass production in this system were most limited by inorganic phosphorus (P) in the eastern and southern regions of the bay. Nutrient additions stimulated productivity and biomass accumulation mostly in summer. The magnitude of growth responses (thymidine incorporation) to nutrient additions was nearly an order of magnitude less in winter than summer. Biomass-normalized alkaline phosphatase activity in the northeast and south-central region was 5–20 times greater than in the northwest and north-central regions, suggesting that P is most limiting to planktonic growth in those areas. Chlorophyll levels were higher in the northwest and north-central regions and P-uptake into particles >1 μm, primarily phytoplankton, was also higher in these regions. Consistent with these observations, others have observed that P is advected into the bay primarily in the northwestern region. Abundant seagrasses in Florida Bay may promote heterotrophic bacterial production relative to phytoplankton production by releasing dissolved organic carbon that makes bacteria more competitive for limiting quantities of inorganic phosphate, especially in the eastern bay where turbidity is low, P is most limiting, and light levels reaching the benthic plants are high.     

Multi-frequency Electromagnetic Induction Survey for Archaeological Prospection: Approach and Results in Han Hangu Pass and Xishan Yang in China

This study presents the potential of multi-frequency electromagnetic induction (EMI) in archaeology. EMI is currently less employed for archaeological prospection with respect to other geophysical techniques. It is capable of identifying shallow subsurface relics by simultaneously measuring the apparent electrical conductivity (EC_a) and apparent magnetic susceptibility (MS_a). Moreover, frequency sounding is able to quantify the depths and vertical shapes of buried structures. In this study, EMI surveys with five frequencies were performed at two heritage sites with different geological conditions: Han Hangu Pass characterized by cinnamon soil and Xishan Yang by sandy loams. In the first site, high EC_a values were observed with variations in depth correlated to archaeological remains. Moreover, electromagnetic anomalies related to an ancient road and five kiln caves were identified. In the second site, an ancient tomb, indicating extremely low EC_a and high MS_a, was discovered. Its electromagnetic properties are attributed to the cavity and ferroferric oxides.     

Space-Based Identification of Archaeological Illegal Excavations and a New Automatic Method for Looting Feature Extraction in Desert Areas

The identification and quantification of disturbance of archaeological sites has been generally approached by visual inspection of optical aerial or satellite pictures. In this paper, we briefly summarize the state of the art of the traditionally satellite-based approaches for looting identification and propose a new automatic method for archaeological looting feature extraction approach (ALFEA). It is based on three steps: the enhancement using spatial autocorrelation, unsupervised classification, and segmentation. ALFEA has been applied to Google Earth images of two test areas, selected in desert environs in Syria (Dura Europos), and in Peru (Cahuachi-Nasca). The reliability of ALFEA was assessed through field surveys in Peru and visual inspection for the Syrian case study. Results from the evaluation procedure showed satisfactory performance from both of the two analysed test cases with a rate of success higher than 90%.     

Corona Satellite Pictures for Archaeological Studies: A Review and Application to the Lost Forbidden City of the Han–Wei Dynasties

This paper provides a state of the art of the use of declassified satellite Corona for archaeological application and deals with the use of historical archives of Corona and aerial photographs for detecting ancient hidden cultural relics that may be completely lost in the modern landscape veiled by current land uses and land covers. Geospatial analysis is adopted to identify, extract and map the subtle archaeological features and cultural landscape of the lost Han–Wei Forbidden City in the Henan Province (China). It was one of the most important cities of ancient China, served as the capital for a long period, from the Eastern Zhou (2600 BP, Zhou Dynasty) to the Eastern Han and Wei Dynasties (1900–1500 BP). Outputs from our investigations clearly provided evidence of numerous buried structures of potential archaeological interest that were compared with historical documentation and excavations carried out in the area. The geospatial analysis, applied both to aerial photograph and to Corona pictures, enabled us to discover a number of unknown sub-palaces and structures, thus providing new insights for this important archaeological area.     

Archaeogeophysical-Based Approach for Inca Archaeology: Overview and one operational application

Even if, in recent decades, the use of remote sensing technologies (from satellite, aerial and ground) for archaeology is stepping into its golden age, in Southern America geophysics for preventive archaeology is more recent and less used than in Europe, Central America and Middle East. In this paper, we provide a brief overview and show the preliminary results obtained from the investigations conducted in Chachabamba (Peru). The archaeological area is located on a strategic terrace overlooking three Inca roads, which served the most important ceremonial centres (including Machu Picchu) of the Urubamba Valley also known as the Sacred Valley. In particular, Chachabamba investigations were conducted with two principal aims: (1) to give new impetus to archaeological research with targeted investigations aimed at improving and completing the site’s knowledge framework; (2) to experiment and validate an archaeogeophysical approach to be reapplied in other sites of the Urubamba valley, including Machu Picchu, having similar characteristics as those found in Chachabamba.     

Robust regression based on shrinkage with application to Living Environment Deprivation

Stochastic Environmental Research and Risk Assessment - A robust estimator is proposed for the parameters that characterize the linear regression problem. It is based on the notion of shrinkages,...     

Scenarios in tropical forest degradation: carbon stock trajectories for REDD+

Background

Human-caused disturbance to tropical rainforests—such as logging and fire—causes substantial losses of carbon stocks. This is a critical issue to be addressed in the context of policy discussions to implement REDD+. This work reviews current scientific knowledge about the temporal dynamics of degradation-induced carbon emissions to describe common patterns of emissions from logging and fire across tropical forest regions. Using best available information, we: (i) develop short-term emissions factors (per area) for logging and fire degradation scenarios in tropical forests; and (ii) describe the temporal pattern of degradation emissions and recovery trajectory post logging and fire disturbance.

Results

Average emissions from aboveground biomass were 19.9 MgC/ha for logging and 46.0 MgC/ha for fire disturbance, with an average period of study of 3.22 and 2.15 years post-disturbance, respectively. Longer-term studies of post-logging forest recovery suggest that biomass accumulates to pre-disturbance levels within a few decades. Very few studies exist on longer-term (>10 years) effects of fire disturbance in tropical rainforests, and recovery patterns over time are unknown.

Conclusions

This review will aid in understanding whether degradation emissions are a substantial component of country-level emissions portfolios, or whether these emissions would be offset by forest recovery and regeneration.