Review of a Semi-Empirical Modelling Approach for Cohesive Sediment Transport in River Systems

In this paper, a review of a semi-empirical modelling approach for cohesive sediment transport in river systems is presented. The mathematical modelling of cohesive sediment transport is a challenge because of the number of governing parameters controlling the various transport processes involved in cohesive sediment, and hence a semi-empirical approach is a viable option. A semi-empirical model of cohesive sediment called the RIVFLOC model developed by Krishnappan is reviewed and the model parameters that need to be determined using a rotating circular flume are highlighted. The parameters that were determined using a rotating circular flume during the application of the RIVFLOC model to different river systems include the critical shear stress for erosion of the cohesive sediment, critical shear stress for deposition according to the definition of Partheniades, critical shear stress for deposition according to the definition of Krone, the cohesion parameter governing the flocculation of cohesive sediment and a set of empirical parameters that define the density of the floc in terms of the size of the flocs. An examination of the variability of these parameters shows the need for testing site-specific sediments using a rotating circular flume to achieve a reliable prediction of the RIVFLOC model. Application of the model to various river systems has highlighted the need for including the entrapment process in a cohesive sediment transport model.

Habitat selection of sympatric Siberian Grouse and Hazel Grouse in natural and exploited forests of the lower Amur region

The Siberian Grouse (Falcipennis falcipennis), which is endemic to the “dark-needle” taiga of the Russian Far East, is one of the least studied grouse species in the world. We examined post-breeding habitat selection of Siberian Grouse and contrasted it with that of the better examined Hazel Grouse (Tetrastes bonasia) in two areas near Komsomolsk na Amure, Russia. To infer species-specific preferences, we used field sampling, logistic regression, and AIC model selection, and compared late summer habitats of Siberian Grouse and Hazel Grouse in a mountain- and hilly area in the dark needle taiga. Our study is the first to explain Siberian Grouse habitat relationships with an empirical modelling approach. Results indicate proportions of coniferous/ pioneer trees forest and rejuvenation to be the most important covariates separating Siberian and Hazel Grouse observation sites in forests from both areas. Siberian Grouse tended to select sites with low proportions of pioneer trees and rejuvenation but availability of dwarf shrubs. Bunchberry (Cornus canadensis) appeared to be of high importance for the presence of Siberian Grouse in both regions. Hazel Grouse were common in places dominated by pioneer trees with high canopy cover, and high proportions of grass/herb cover. Hazel Grouse also occurred more often in forest sites with dense vertical layering and rejuvenation. Modern forestry, which results in increasing amounts of forests at younger successional stages, is likely to favour the Hazel Grouse at the expense of the Siberian Grouse.

Simulation-Based Participatory Modelling in Urban and Production Logistics: A Review on Advances and Trends

Simulation-based participatory modelling allows integration of all types of knowledge including empirical, technical and scientific from all disciplines and domains. Thus, in recent years, the use of participatory modelling has been continuously increasing in many fields including logistics. With a view of achieving better understanding of the subject, this article systematically reviews the advances made in participatory modelling in the field of urban and production logistics in the last decade. It further reports the findings transparently following a categorization based on (i) the purpose of participatory modelling in the domain, and (ii) depending on the purpose how data is collected, processed and outcomes are presented. The review resulted in 97 articles which were analysed and categorized based on the above two questions formulated in the literature surveyed. The review revealed that apart from the three existing categories of purposes, namely, reflexive, descriptive and normative there is an emerging fourth category that was analytical in nature and 15 out of 97 articles analyzed belonged to this category. The authors decided to call this category analytical field empirical modelling which is primarily based on mathematical modelling and use of computational methods. We present these results with the help of a categorization. During the analysis for the second research question, we discovered that though the conventional ways of data collection and processing, such as interviews and workshops, which remain significantly present, in electronic data crowdsourcing and data processing via computational methods are emerging.

Empirical modelling of snow cover duration patterns in complex terrains of Italy

Snow cover duration is a crucial climate change indicator. However, measurements of days with snow cover on the ground (DSG) are limited, especially in complex terrains, and existing measurements are fragmentary and cover only relatively short time periods. Here, we provide observational and modelling evidence that it is possible to produce reliable time-series of DSG for Italy based on instrumental measurements, and historical documentary data derived from various sources, from a limited set of stations and areas in the central-southern Apennines (CSA) of Italy. The adopted modelling approach reveals that DSG estimates in most settings in Italy can be driven by climate factors occurring in the CSA. Taking into account spatial scale-dependence, a parsimonious model was developed by incorporating elevation, winter and spring temperatures, a large-scale circulation index (the Atlantic Multidecadal Variability, AMV) and a snow-severity index, with in situ DSG data, based on a core snow cover dataset covering 97 years (88% coverage in the 1907–2018 period and the rest, discontinuously from 1683 to 1895, from historical data of the Benevento station). The model was validated on the basis of the identification of contemporary snow cover patterns and historical evidence of summer snow cover in high massifs. Beyond the CSA, validation obtained across terrains of varying complexity in both the northern and southern sectors of the peninsula indicate that the model holds potential for applications in a broad range of geographical settings and climatic situations of Italy. This article advances the study of past, present and future DSG changes in the central Mediterranean region.

What Makes a Commuter Cyclist? A Mixed Methods Study of Behavioural Antecedents and Perceptions of Commuter Cycling in the Wellington Region

<p>Encouraging active transport contributes to both environmental sustainability and public health objectives. However, due to a myriad of physical, societal and personal factors, shifting car trips to the bicycle is notoriously difficult especially in societies where car use is deeply engrained in both the social and urban fabric. It is therefore important to explore novel approaches to promote utilitarian cycling. Past studies have suggested there may be a link between cycling for recreation and cycling for transport. If this is the case, one could hypothesise that policies that promote recreational cycling may also indirectly promote utilitarian cycling. This study begins to explore this important research question by investigating whether recreational cyclists are more amenable to utilitarian cycling than non-cyclists, using a case study of commuting in the Wellington Region of New Zealand. Behaviour theory, based on the Theory of Planned Behaviour, provided the conceptual framework for a mixed methods analysis of Wellington Region commuters. Empirical modelling of commuter cycling behaviour showed that almost all antecedents of the behaviours of recreational cyclists are closer to those of commuter cyclists than to non-cyclists. Qualitative analysis provided further evidence that recreational cyclists are more prepared and willing to cycle their commute than non-cyclists. It is concluded that, for the study sample, recreational cyclists are indeed more amenable to commuting by bicycle than non-cyclists in the Wellington region.</p>

What Makes a Commuter Cyclist? A Mixed Methods Study of Behavioural Antecedents and Perceptions of Commuter Cycling in the Wellington Region

<p>Encouraging active transport contributes to both environmental sustainability and public health objectives. However, due to a myriad of physical, societal and personal factors, shifting car trips to the bicycle is notoriously difficult especially in societies where car use is deeply engrained in both the social and urban fabric. It is therefore important to explore novel approaches to promote utilitarian cycling. Past studies have suggested there may be a link between cycling for recreation and cycling for transport. If this is the case, one could hypothesise that policies that promote recreational cycling may also indirectly promote utilitarian cycling. This study begins to explore this important research question by investigating whether recreational cyclists are more amenable to utilitarian cycling than non-cyclists, using a case study of commuting in the Wellington Region of New Zealand. Behaviour theory, based on the Theory of Planned Behaviour, provided the conceptual framework for a mixed methods analysis of Wellington Region commuters. Empirical modelling of commuter cycling behaviour showed that almost all antecedents of the behaviours of recreational cyclists are closer to those of commuter cyclists than to non-cyclists. Qualitative analysis provided further evidence that recreational cyclists are more prepared and willing to cycle their commute than non-cyclists. It is concluded that, for the study sample, recreational cyclists are indeed more amenable to commuting by bicycle than non-cyclists in the Wellington region.</p>