Bayesian hierarchical models for analysing the spatial distribution of bioclimatic indices

A methodological approach for modelling the spatial distribution of bioclimatic indices is proposed in this paper. The value of the bioclimatic index is modelled with a hierarchical Bayesian model that incorporates both structured and unstructured random effects. Selection of prior distributions is also discussed in order to better incorporate any possible prior knowledge about the parameters that could refer to the particular characteristics of bioclimatic indices. MCMC methods and distributed programming are used to obtain an approximation of the posterior distribution of the parameters and also the posterior predictive distribution of the indices. One main outcome of the proposal is the spatial bioclimatic probability distribution of each bioclimatic index, which allows researchers to obtain the probability of each location belonging to different bioclimates. The methodology is evaluated on two indices in the Island of Cyprus.Peer Reviewe

How predation and landscape fragmentation affect vole population dynamics

Background: Microtine species in Fennoscandia display a distinct north-south gradient from regular cycles to stable populations. The gradient has often been attributed to changes in the interactions between microtines and their predators. Although the spatial structure of the environment is known to influence predator-prey dynamics of a wide range of species, it has scarcely been considered in relation to the Fennoscandian gradient. Furthermore, the length of microtine breeding season also displays a north-south gradient. However, little consideration has been given to its role in shaping or generating population cycles. Because these factors covary along the gradient it is difficult to distinguish their effects experimentally in the field. The distinction is here attempted using realistic agent-based modelling. Methodology/Principal Findings: By using a spatially explicit computer simulation model based on behavioural and ecological data from the field vole (Microtus agrestis), we generated a number of repeated time series of vole densities whose mean population size and amplitude were measured. Subsequently, these time series were subjected to statistical autoregressive modelling, to investigate the effects on vole population dynamics of making predators more specialised, of altering the breeding season, and increasing the level of habitat fragmentation. We found that fragmentation as well as the presence of specialist predators are necessary for the occurrence of population cycles. Habitat fragmentation and predator assembly jointly determined cycle length and amplitude. Length of vole breeding season had little impact on the oscillations. Significance: There is good agreement between our results and the experimental work from Fennoscandia, but our results allow distinction of causation that is hard to unravel in field experiments. We hope our results will help understand the reasons for cycle gradients observed in other areas. Our results clearly demonstrate the importance of landscape fragmentation for population cycling and we recommend that the degree of fragmentation be more fully considered in future analyses of vole dynamics

Guidelines for the scoping and environmental assessment of water resources projects. The environment and water resources projects - Volume 2

In its role as protector of the water environment, the Environment Agency requires significant water resources abstraction applications and schemes such as drought orders, drought permits, time limited licences, and river transfers to be environmentally assessed leading to the production of an environmental report or statement. This may not take the form of a formal Environmental Assessment, but is required to provide environmental information to support applications. (See Volume 1 - Guidance for Scoping and Environmental Assessment for Water Resources Projects in North East Region). This second volume concentrates on the environmental monitoring component of environmental assessments

Actors and factors - bridging social science findings and urban land use change modeling

Recent uneven land use dynamics in urban areas resulting from demographic change, economic pressure and the cities’ mutual competition in a globalising world challenge both scientists and practitioners, among them social scientists, modellers and spatial planners. Processes of growth and decline specifically affect the urban environment, the requirements of the residents on social and natural resources. Social and environmental research is interested in a better understanding and ways of explaining the interactions between society and landscape in urban areas. And it is also needed for making life in cities attractive, secure and affordable within or despite of uneven dynamics.\ud The position paper upon “Actors and factors – bridging social science findings and urban land use change modeling” presents approaches and ideas on how social science findings on the interaction of the social system (actors) and the land use (factors) are taken up and formalised using modelling and gaming techniques. It should be understood as a first sketch compiling major challenges and proposing exemplary solutions in the field of interest

Analysing the visual dynamics of spatial morphology

Recently there has been a revival of interest in visibility analysis of architectural configurations. The new analyses rely heavily on computing power and statistical analysis, two factors which, according to the postpositivist school of geography, should immediately cause us to be wary. Thedanger, they would suggest, is in the application of a reductionist formal mathematical description in order to `explain' multilayered sociospatial phenomena. The author presents an attempt to rationalise how we can use visibility analysis to explore architecture in this multilayered context by considering the dynamics that lead to the visual experience. In particular, it is recommended that we assess the visualprocess of inhabitation, rather than assess the visibility in vacuo. In order to investigate the possibilities and limitations of the methodology, an urban environment is analysed by means of an agent-based model of visual actors within the configuration. The results obtained from the model are compared with actual pedestrian movement and other analytic measurements of the area: the agents correlate well both with human movement patterns and with configurational relationship as analysed by space-syntax methods. The application of both methods in combination improves on the correlation with observed movement of either, which in turn implies that an understanding of both the process of inhabitation and the principles of configuration may play a crucial role in determining the social usage of space

A review of wildland fire spread modelling, 1990-present 3: Mathematical analogues and simulation models

In recent years, advances in computational power and spatial data analysis (GIS, remote sensing, etc) have led to an increase in attempts to model the spread and behvaiour of wildland fires across the landscape. This series of review papers endeavours to critically and comprehensively review all types of surface fire spread models developed since 1990. This paper reviews models of a simulation or mathematical analogue nature. Most simulation models are implementations of existing empirical or quasi-empirical models and their primary function is to convert these generally one dimensional models to two dimensions and then propagate a fire perimeter across a modelled landscape. Mathematical analogue models are those that are based on some mathematical conceit (rather than a physical representation of fire spread) that coincidentally simulates the spread of fire. Other papers in the series review models of an physical or quasi-physical nature and empirical or quasi-empirical nature. Many models are extensions or refinements of models developed before 1990. Where this is the case, these models are also discussed but much less comprehensively.Comment: 20 pages + 9 pages references + 1 page figures. Submitted to the International Journal of Wildland Fir

De/construction sites: Romans and the digital playground

The Roman world as attested to archaeologically and as interacted with today has its expression in a great many computational and other media. The place of visualisation within this has been paramount. This paper argues that the process of digitally constructing the Roman world and the exploration of the resultant models are useful methods for interpretation and influential factors in the creation of a popular Roman aesthetic. Furthermore, it suggests ways in which novel computational techniques enable the systematic deconstruction of such models, in turn re-purposing the many extant representations of Roman architecture and material culture

Development Scenarios for Eastern European Cities and Regions in the New Europe

In this paper we focus on urban growth dynamics of Eastern European cities and regions in the past and in the new Europe. This work is a part of on-going research in the field of urban and regional development, carried out in Joint Research Centre (JRC) of the European Commission. Eastern European cities experienced similar and very turbulent historical and political development during 20th century. The policies during the communist period with planned economy has clearly reflected in the land use pattern development, e.g. the absence of large suburbs and underdeveloped transport networks around cities. In contrast to other European cities, no or very few commercial zones and commercial centres were built in suburban areas. In addition, satellite cities were built only on a limited scale. With the collapse of communist regimes cities and regions in Eastern Europe have entered into a new phase of urbanisation, which changes dramatically land use patterns. The liberalization of economy and the membership of the EU has led to the growing involvement to the European market and EU development schemes (e.g. TEN/T, ERDF, etc.). In spite of the expected decrease of population in the new EU countries the average gross domestic product is projected to triple and the number of households per capita is projected to double between 2000 and 2030 (EEA, 2005¬/4). Among the consequences of socio-economic development the continuous growth of urban areas can be foreseen. What shapes urban sprawl will take and will it cause new threads to sustainability remains to be seen. In this paper we focus on two study cases (1) the Dresden – Prague transport corridor in Germany and in the Czech Republic (Barredo et al, 2005) and (2) the Harjumaa region and the city of Tallinn in Estonia. The objective of this work is to test the impact of diverse economic development trends on urbanisation processes. Several development scenarios are produced in order to model the spatial pattern of urban land use. The MOLAND urban and regional growth simulation model (Lavalle et al, 2004), based on “cellular automata†(CA), is a key instrument in the forecasting land use development. The model operates at two levels. At the micro- level, the CA-based model determines the fate of individual land use cells based on the type of the activities in their neighbourhood. At the macro- level, various additional factors such as overall land use demand, effects of the transportation network as well as legislative, environmental and institutional characteristics (e.g. environmental protection, zoning) constrain the behaviour of the CA-model. This approach allowed us to integrate “physicalâ€, environmental, socio-economic development as well as institutional aspect of territorial development. The scenarios offer a useful approach to analysing and understanding urban land use dynamics and can also serve for landscape management at the local and regional scales, complementing existing policies and programmes. In both study cases we evaluate the impact newly developed motorways’ supported by EU Structural Funds. Very important feature of Dresden-Prague corridor is the extreme flood events in 2002. The increasing vulnerability to natural hazards due to rapid urban development in flood-prone area is also discussed in the paper.