DmpIRFs and DmpST:DAMPE instrument response functions and science tools for gamma-ray data analysis

Observing GeV gamma-rays is an important goal of the DArk Matter Particle Explorer(DAMPE)for indirect dark matter searching and high energy astrophysics. In this work, we present a set of accurate instrument response functions for DAMPE(DmpIRFs) including the effective area, point-spread function and energy dispersion, which are crucial for gamma-ray data analysis based on statistics from simulation data. A dedicated software named DmpST is developed to facilitate the scientific analyses of DAMPE gamma-ray data. Considering the limited number of photons and angular resolution of DAMPE, the maximum likelihood method is adopted in DmpST to better disentangle different source components. The basic mathematics and framework regarding this software are also introduced in this paper.     

Managing tourist harbors: Are managers aware of the real environmental risks?

The management of tourist harbors has traditionally been analyzed with little attention to managers’ awareness of the effects of their decisions on the environment. The aims of this paper were to assess managers’ perceptions of the main environmental risks in their regions and to identify common behaviors among the managers involved in eight tourist harbors in southern Italy, where the same tourist harbor is often managed by different managers. A questionnaire was administered and statistical analyses were performed to test differences between managers of big and small harbors. Managers showed a low perception of environmental risks and, surprisingly, in certain harbors, some meaningful cases were highlighted: the most homogeneous case, where all managers showed a reasonable level of environmental awareness, and cases with strong mismatches among managers. In this paper, we propose that an assessment of managers’ perceptions of risk be included as a new form of analysis when environmental risk assessments are carried out.     

Morphological effects of different channel‐forming discharges in a gravel‐bed river

The study analyses the morphological response of a gravel‐bed river to discharges of different magnitude (from moderate events that occur several times a year to a 12‐year flood) and so defines the range of formative discharges for single morphological units (channels, bars, islands) and a range of magnitude of morphological activity from the threshold discharges for gravel transport and minor bar modification up to flows causing major morphological changes. The study was conducted on the Tagliamento River, a large gravel‐bed river in north‐eastern Italy, using two different methods, analysis of aerial photographs and field observation of painted gravel particles. The available photographs (five flights from August 1997 to November 2002) and the two commissioned flights (June 2006 and April 2007) do not define periods with a single flood event, but the intervals are short enough (11 to 22 months) to have a limited number of flood events in each case. The fieldwork, which involved cross‐section survey, grain‐size analysis and observation of painted sediments, complemented the aerial surveys by allowing analysis of channel response to single flood events. Substantial morphological changes (e.g. bank erosion of several tens of metres up to more than 100 m) associated with flood events with a recurrence interval between 1·1 year and 12 years have been documented. Multiple forming discharges were defined based on the activity of different morphological units. Discharges equal to 20–50% of the bankfull discharge are formative for the channels, whereas the bankfull discharge (1·1 year flood in this case of the Tagliamento River) is formative for low bars. Larger floods, but still relatively frequent (with a recurrence interval less than five years), are required for full gravel transport on high bars and significant morphological changes of islands. Copyright © 2009 John Wiley & Sons, Ltd.     

Nursery areas of red mullet (Mullus barbatus), hake (Merluccius merluccius) and deep-water rose shrimp (Parapenaeus longirostris) in the Eastern-Central Mediterranean Sea

The spatial pattern of the nursery areas of red mullet (Mullus barbatus), hake (Merluccius merluccius) (Linnaeus, 1758) and deep-water rose shrimp (Parapenaeus longirostris) (Lucas, 1846) was studied in the South Adriatic and North Ionian Seas (Eastern-Central Mediterranean) applying geostatistical techniques and data from time series trawl surveys conducted in the area. The analysed variables were: R (number of recruits/km²) and R/Tot (fraction of recruits on the total sampled population). The structural analysis showed a spatial pattern of both variables characterized by continuity on a small scale. Predictions of nursery area localization with probability of finding recruits at different threshold values were obtained through median indicator kriging. For the red mullet the nurseries were mainly identified in the South Adriatic Sea off the Gargano peninsula and between Molfetta and Monopoli within 50 m in depth. The main concentration of hake juveniles was found to be between 100 and 200 m in depth along the Gargano peninsula and between Otranto and Santa Maria di Leuca, where a nursery of deep-water rose shrimp was also detected. An overlapping depth, between 100 and 200 m, was identified for hake and deep-water rose shrimp nurseries. Protection of these areas through limitations of fishing pressure is discussed.     

Multi-thread river channels: A perspective on changing European alpine river systems

Rivers are natural systems whose planform pattern in alluvial reaches reflects a balance between three fundamental ingredients: flow energy, sediment calibre and supply, and vegetation. Whilst early research on river channel classification emphasised flow (stream power) and sediment controls, the impact of vegetation is now recognised in increasingly detailed classification schemes. Different planform patterns are more or less sensitive to changes in these three fundamental ingredients, which in the absence of human interventions all respond to changes in climate, allowing different morphological configurations to evolve and in some cases shift from one planform style to another. Multi-thread, braided and transitional river channel styles are common in European regions where conditions for the development of these planform styles, notably high bed material supply and steep channel gradients, exist. However, widespread, intense human impacts on European river systems, particularly over recent centuries, have caused major changes in river styles. Human activities impact on all three major controls on channel pattern: flow regime, sediment regime, vegetation (both riparian and catchment-wide). Whilst the mix of human activities may vary greatly between catchments, research from across Europe on the historical evolution of river systems has identified consistent trends in channel pattern change, particularly within rivers draining the Alps. These trends involve periods of narrowing and widening, and also switching between multi-thread and single-thread styles. Although flow regulation is often the key focus of explanations for human-induced channel change, our review suggests that human manipulation of sediment supply is a major, possibly the dominant, causal factor. We also suggest that “engineering” by riparian trees can accelerate transitions in pattern induced by flow and sediment change and can also shift transition thresholds, offering a new perspective for interpretation of channel change in addition to the focus on flow and sediment regime within existing models. Whilst the development of planform classifications of increasing complexity have been crucial in developing terminology and highlighting the main factors that control channel styles, additional approaches are needed to understand, predict and manage European Alpine river systems. A combination of field, laboratory and numerical modeling approaches are needed to advance the process understanding that is necessary to anticipate river landscape, particularly planform, changes and thus to make ecologically sound management choices.     

Distribution and population structure of deep‐dwelling red coral in the Northwest Mediterranean

Commercially harvested since ancient times, the highly valuable red coral Corallium rubrum (Linnaeus, 1758) is an octocoral endemic to the Mediterranean Sea and adjacent Eastern Atlantic Ocean, where it occurs on rocky bottoms over a wide bathymetric range. Current knowledge is restricted to its shallow populations (15–50 m depth), with comparably little attention given to the deeper populations (50–200 m) that are nowadays the main target of exploitation. In this study, red coral distribution and population structure were assessed in three historically exploited areas (Amalfi, Ischia Island and Elba Island) in the Tyrrhenian Sea (Western Mediterranean Sea) between 50 and 130 m depth by means of ROV during a cruise carried out in the summer of 2010. Red coral populations showed a maximum patch frequency of 0.20 ± 0.04 SD patches·m^?1 and a density ranging between 28 and 204 colonies·m^?2, with a fairly continuous bathymetric distribution. The highest red coral densities in the investigated areas were found on cliffs and boulders mainly exposed to the east, at the greatest depth, and characterized by medium percentage sediment cover. The study populations contained a high percentage (46% on average) of harvestable colonies (>7 mm basal diameter). Moreover, some colonies with fifth‐order branches were also observed, highlighting the probable older age of some components of these populations. The Ischia population showed the highest colony occupancy, density and size, suggesting a better conservation status than the populations at the other study locations. These results indicate that deep dwelling red coral populations in non‐stressed or less‐harvested areas may diverge from the inverse size‐density relationship previously observed in red coral populations with increasing depth.     

Monitoring vegetation and land use quality along the rural-urban gradient in a Mediterranean region

This paper illustrates a methodology to quantify vegetation quality and its possible degradation in a large ‘shrinking’ Mediterranean city. Vegetation quality was estimated at three years (1960, 1990, 2006) in the Nuts-3 prefecture of Rome, central Italy (5355 km²) through the analysis of comparable land cover maps. The aims of this work are to assess how ‘compact growth’ and ‘sprawl’ impact on vegetation quality, and to monitor the territorial disparities observed in the vegetation quality as caused by urbanization and land use polarization. Built-up areas covered 3.3% and 12.9% of the investigated area in 1960 and 2006, respectively, with a dispersed to compact urban surface ratio passing from 1.2 to 1.9. Vegetation quality increased slightly during the investigated period with a diverging trend between urban and rural areas. As a consequence, territorial disparities in the same variable grew due to low-density urban diffusion in lowlands and depopulation with land abandonment and natural forestation in mountain areas.     

The coral assemblages of an off‐shore deep Mediterranean rocky bank (NW Sicily,Italy)

In this study we characterized the deep assemblages dwelling at 200–250 m depth on a large shoal off Capo St. Vito Promontory (Northwestern coast of Sicily, South Tyrrhenian Sea) by means of ROV‐imaging. Two assemblages of suspension feeders, dominated by the gorgonian Callogorgia verticillata and by the black coral Leiopathes glaberrima, together with a tanatocoenosis of the colonial yellow scleractinian coral Dendrophyllia cornigera, were examined. The three main species were significatively distributed into two areas corresponding to different habitat preferences: a more elevated hardground hosting black corals and a gently sloping, silted rocky bottom hosting the other coral species. The study area is subjected to a heavy pressure from the professional fishery, resulting in the mechanical damage of numerous colonies, some of which are then overgrown by various epibionts including a parasitic bioluminescent zoanthid, new for the Mediterranean fauna, and tentatively identified as Isozoanthus primoidus. In the Mediterranean Sea, these deep off‐shore rocky banks are widely known among recreational and professional fishermen due to their rich fish fauna. However, there has been still little effort into quantifying and characterizing the extent of the impact and its consequences on the benthic communities, which may represent, as in this case, only a partial picture of their original structure and extent.     

Monitoring Etna volcanic plumes using a scanning LiDAR

In this paper, we use data obtained from LiDAR measurements during an ash emission event on 15 November 2010 at Mt. Etna, in Italy, in order to evaluate the spatial distribution of volcanic ash in the atmosphere. A scanning LiDAR system, located at 7?km distance from the summit craters, was directed toward the volcanic vents and moved in azimuth and elevation to analyse different volcanic plume sections. During the measurements, ash emission from the North East Crater and high degassing from the Bocca Nuova Crater were clearly visible. From our analysis we were able to: (1) evaluate the region affected by the volcanic plume presence; (2) distinguish volcanic plumes containing spherical aerosols from those having non-spherical ones; and (3) estimate the frequency of volcanic ash emissions. Moreover, the spatial distribution of ash mass concentration was evaluated with an uncertainty of about 50?%. We found that, even during ash emission episodes characterised by low intensity like the 15 November 2010 event, the region in proximity of the summit craters should be avoided by air traffic operations, the ash concentration being greater than 4?×?10^?3?g/m³. The use of a scanning permanent LiDAR station may usefully monitor the volcanic activity and help to drastically reduce the risks to aviation operations during the frequent Etna eruptions.