Morphology and evolution of simulated and optical clusters: a comparative analysis

We have made a comparative study of morphological evolution in simulated dark matter (DM) haloes and X-ray brightness distribution, and in optical clusters. Samples of simulated clusters include star formation with supernovae feedback, radiative cooling and simulation in the adiabatic limit at three different redshifts,   z = 0.0, 0.10  and 0.25. The optical sample contains 208 Abell, Corwin & Olowin (ACO) clusters within redshift,   z ≤ 0.25  . Cluster morphology, within 0.5 and 1.0 h ⁻¹ Mpc from cluster centre, is quantified by multiplicity and ellipticity.
We find that the distribution of the DM haloes in the adiabatic simulation appears to be more elongated than the galaxy clusters. Radiative cooling brings halo shapes in excellent agreement with observed clusters; however, cooling along with feedback mechanism makes the haloes more flattened.
Our results indicate relatively stronger structural evolution and more clumpy distributions in observed clusters than in the structure of simulated clusters, and slower increase in simulated cluster shapes compared to those in the observed one.
Within   z ≤ 0.1  , we note an interesting agreement in the shapes of clusters obtained from the cooling simulations and observation. We also note that the different samples of observed clusters differ significantly in morphological evolution with redshift. We highlight a few possibilities responsible for the discrepancy in morphological evolution of simulated and observed clusters.     

New Hormaphididae (Hemiptera, Aphidomorpha) from the Baltic Amber and its Palaeogeographic Significance

The present study describes a new genus and species Unicohormaphis sorini, which belongs to the subfamily Cerataphidinae. The contemporary distribution of aphids belonging to the Hormaphididae family is summarized and analyzed. According to the obtained data, the climate warming in Eocene was conducive to the expansion of the family over the areas of Europe. Subsequent climate changes, resulting from epeirogenic and orogenic movements towards the end of Eocene, led to a considerable cooling and drying of climate in the northern hemisphere. These processes contributed to the shrinking down of areas covered by subtropical forests, which constituted the habitat of Hormaphididae (Cerataphidinae). Retaining their way of life, the Cerataphidinae were forced to limit their distribution, and the representatives of the family in Europe became completely extinct.     

The anisotropy of galaxy orientation in the Coma/A1367 supercluster

The spatial orientations of the galactic planes for galaxies in the Coma/A1367 supercluster have been determined. Owing to the ambiguity in the determination of the inclination angle, two possible orientations of the normal to the galaxy plane were found. Two angles, the polar angle δ _D and the azimuthal angle η , describe the orientation of normals. The distribution of both angles has been checked for isotropy. It is shown that the distribution is not isotropic. The same alignment is observed for samples containing elliptical and lenticular galaxies and for samples containing only spirals, as well as for samples containing galaxies located in different parts of the supercluster. In the case of spiral galaxies, the anisotropy shows that galaxy rotation axes strongly favour alignment with the main plane of the supercluster. The projection of the rotation axes on to the main plane of the supercluster has a preferential direction pointing towards the supercluster, but this effect is weak. A comparison with theory is also presented.     

Where will widening occur in an outwash braidplain? A new approach to detecting controls on fluvial lateral erosion in a glacierized catchment (north-western Spitsbergen,Svalbard)

The dynamics of fluvial system evolution depend on fluvial processes and their driving forces associated with climatic variations, which affect changes in the morphology of river channels and floodplains. Neither channel slope and morphology, nor the properties of fluvial sediment have previously been considered as determinants of active braidplain widening on outwash plains (formed from valley/alpine glaciers and confined by pre-existing topography) in the High Arctic region and in the forefields of retreating glaciers. Factors determining widening of braidplain activity of the Waldemar River outwash (north-western Spitsbergen, Svalbard) were analysed on the basis of geomorphological, sedimentological, glaciological and meteorological research, and indicate significant multiple correlations between meltwater discharge, precipitation, braidplain width, morphology of the braided channel and the textural features of braidplain deposits. The capability of multivariate adaptive regression splines to detect these relationships was described, and threshold values were identified. The results indicate that the rate of active braidplain widening is proportional to the meltwater outflow in proglacial rivers, which can decrease despite a growing rate of glacial ablation. A proposed model enables us to predict zones of braidplain prone to widening activity in the High Arctic (humid) outwash fans and plains as well as fans developed in arid intermountain basins. The necessary conditions to activate braidplain widening processes were (1) spatial changes in the outwash feeding system due to glacier terminus retreat and (2) crossing the thresholds in passive factors (S and d₅₀) controlling lateral erosion intensity. As a result, the braidplain reached a new dynamic equilibrium, in which high-magnitude–low-frequency extreme meltwater discharges were of particular importance in terms of braidplain dynamics and are the dominant controls on the pattern of distributary channels.     

Understanding User Interaction Patterns within Online Systems for Public‐Participation Transportation Planning

Many research projects in public‐participation geographic information systems focused on the development of software prototypes that were conceptualized to complement traditional forms of public participation. Given the challenges introduced by the heterogeneity of their user base, system design, and decision making process, empirical evaluations of such systems based on actual use have been scarce. This article reports on a rigorous empirical assessment of human‐computer interaction of users of a web‐based system for participatory transportation planning. We devised three groups of participants with below‐average, average, and above‐average interaction duration through hierarchical cluster analysis. Subsequently, the characteristics of the clusters were subjected to logistic regression analysis to determine the significance and strength of statistical associations between duration of interaction and a host of individual‐level variables. Our results indicate a statistically significant reduction of the odds‐ratio for participants with above‐average duration of interaction in the case of no prior experience with online transportation discussions. No significant associations were found between overall duration of interaction and sociodemographic background, cognitive decision‐making style, and travel behavior. We advocate for the development of adaptable participatory systems which accommodate flexibility in terms of both the user interface and pathways of the decision making process.     

Emerging trends and research frontiers in spatial multicriteria analysis

ABSTRACT

A majority of research on Spatial Multicriteria Analysis (SMCA) has been spatially implicit. Typically, SMCA uses conventional (aspatial) multicriteria methods for analysing and solving spatial problems. This paper examines emerging trends and research frontiers related to the paradigm shift from spatially implicit to spatially explicit multicriteria analysis. The emerging trend in SMCA has been spatially explicit conceptualizations of multicriteria problems focused on multicriteria analysis with geographically varying outcomes and local multicriteria analysis. The research frontiers align with conceptual and structural elements of SMCA and pertain to, among others, theoretical frameworks, problem structuring, model parameter derivation, decision problem contextualization, scale representation, treatment of uncertainties, and the very meaning of decision support. The paper also identifies research directions and challenges associated with developing spatially explicit multicriteria methods and integrating concepts and approaches from two distinct fields: GIS and multicriteria analysis.     

Buried Late Weichselian thermokarst landscape discovered in the Czech Republic,central Europe

Pronounced climatic warming associated with the Late Weichselian Pleniglacial‐to‐Lateglacial transition caused considerable environmental changes throughout the former periglacial zones (in Europe ~53°–46°N). During permafrost degradation and subsequent ground subsidence (i.e. thermokarst processes), the landscape changed rapidly. In this study we investigated a flat mid‐altitude area in south Bohemia, Czech Republic, lying close to the southern limit of the Weichselian permafrost. We discovered palaeo‐lake basins with sedimentary infillings up to 11 m in depth. According to radiocarbon and palynostratigraphical dating, these basins were formed at the onset of the Late Pleniglacial‐to‐Lateglacial transition, whereas the smaller depressions were formed later. We suggest that the basins resulted from thermal and fluvio‐thermal erosion of the former permafrost and represent remnants of discontinuous gullies and possibly collapsed frost mounds (pingo/lithalsa scars). The formation of this a fossil thermokarst landscape was climatically driven and multiple phased, with the major phase during the climatic warming and wetting at the onset of GI‐1e (Bølling) and the minor phase during GI‐1c (Allerød). This study enhances knowledge of the palaeogeography of the former European periglacial zone by showing that Late Pleistocene thermokarst activity could have had a significant impact on the evolution of the landscape of at least some regions of central Europe along the southern limit of the continuous permafrost zone. The research also points to a similar history for the physical transformation of the landscape of the former European periglacial zone and current thermokarst landscapes and could be a valuable source of information with respect to the future transformation of the Arctic under conditions of ongoing global warming.     

Hydrodynamic parameters in a flood impacted boulder block ramp: Krzczonówka mountain stream,Polish Carpathians

Boulder block ramps are river engineering structures used to stabilise river beds. Block ramps provide a semi-natural and aesthetically pleasing solution to certain river engineering problems in mountain streams. When constructing block ramps,one can use the dissipative behaviour of large macroroughness elements randomly placed on the river bed to enhance fish migration in an upstream direction thus, in this sense, meeting the requirements of the EU Water Framework Directive. Block ramps are often designed and constructed to replace damaged drop hydraulic structures in the channels of mountain streams. This paper investigates the resilience of a particular block ramp placed in the Krzczonówka stream(Polish Carpathians) in terms of the engineering design function and its durability against damaging. A hydrodynamic analysis of a block ramp is presented before and after a flood event that changed the configuration of the blocks. The seminatural unstructured hydraulic structure was built on the Krzczonowka stream to protect gas pipes which are located beneath it. As a result of several floods, the boulder block chute described in this paper was damaged, and some boulders were dislodged and transported downstream. Our post-flood investigations of bathymetry and velocity revealed that even damaged boulder blocks, removed from the chute and displaced downstream of the structure, still provide significant energy dissipation of the flowing water. The novel of our paper is for the first time showing very detailed analysis of unstructured block ramp hydrodynamics parameters done in the field.Also the novel finding of our investigations shows that before and after the flood event the unstructured block ramp structure, is still fish friendly in terms of hydrodynamics.     

Quantitative and Qualitative Assessment of Soil Erosion Risk in Małopolska (Poland), Supported by an Object-Based Analysis of High-Resolution Satellite Images

In 2011 the Marshal Office of Ma?opolska Voivodeship decided to evaluate the vulnerability of soils to water erosion for the entire region. The quantitative and qualitative assessment of the erosion risk for the soils of the Ma?opolska region was done based on the USLE approach. The special work-flow of geoinformation technologies was used to fulfil this goal. A high-resolution soil map, together with rainfall data, a detailed digital elevation model and statistical information about areas sown with particular crops created the input information for erosion modelling in GIS environment. The satellite remote sensing technology and the object-based image analysis (OBIA) approach gave valuable support to this study. RapidEye satellite images were used to obtain the essential up-to-date data about land use and vegetation cover for the entire region (15,000 km²). The application of OBIA also led to defining the direction of field cultivation and the mapping of contour tillage areas. As a result, the spatially differentiated values of erosion control practice factor were used. Both, the potential and the actual soil erosion risk were assessed quantificatively and qualitatively. The results of the erosion assessment in the Ma?opolska Voivodeship reveal the fact that a majority of its agricultural lands is characterized by moderate or low erosion risk levels. However, high-resolution erosion risk maps show its substantial spatial diversity. According to our study, average or higher actual erosion intensity levels occur for 10.6 % of agricultural land, i.e. 3.6 % of the entire voivodeship area. In 20 % of the municipalities there is a very urgent demand for erosion control. In the next 23 % an urgent erosion control is needed. Our study showed that even a slight improvement of P-factor estimation may have an influence on modeling results. In our case, despite a marginal change of erosion assessment figures on a regional scale, the influence on the final prioritization of areas (municipalities) according to erosion control needs is visible. The study shows that, high-resolution satellite imagery and OBIA may be efficiently used for P-factor mapping and thus contribute to a refined soil erosion risk assessment.     

The significance of landforms – the contribution of geomorphology to the World Heritage Programme of UNESCO

This discussion paper addresses the role of geomorphology in designating UNESCO World Heritage properties. Two of the defined criteria employed in the process are explicitly relevant to geomorphology. Criterion (vii) emphasizes the occurrence of superlative natural phenomena, while criterion (viii) directly refers to landforms and on‐going surface processes, along with historical geological values. Superlative natural phenomena may be singular features, but in recent nominations the focus has tended to be on geomorphic diversity over limited areas. Overall, this is a criterion significantly influenced by subjective judgement. The significance of landforms, as included in the wording of criterion (viii), may be considered in three ways. Landforms may be significant for the science of geomorphology itself, and/or for other natural science disciplines, particularly biology and ecology, and/or be of wider cultural significance, including for history, architecture, general landscape aesthetics, art, or religion, underpinning cultural developments. To better determine the conditions to be fulfilled by a property to be considered as geomorphologically significant at the highest global level required for World Heritage listing seems a timely and useful exercise. Copyright © 2014 John Wiley & Sons, Ltd.