Postglacial relative sea‐level observations from Ireland and their role in glacial rebound modelling

The British Isles have been the focus of a number of recent modelling studies owing to the existence of a high‐quality sea‐level dataset for this region and the suitability of these data for constraining shallow earth viscosity structure, local to regional ice sheet histories and the magnitude/timing of global meltwater signals. Until recently, the paucity of both glaciological and relative sea‐level (RSL) data from Ireland has meant that the majority of these glacial isostatic adjustment (GIA) modelling studies of the British Isles region have tended to concentrate on reconstructing ice cover over Britain. However, the recent development of a sea‐level database for Ireland along with emergence of new glaciological data on the spatial extent, thickness and deglacial chronology of the Irish Ice Sheet means it is now possible to revisit this region of the British Isles. Here, we employ these new data to constrain the evolution of the Irish Ice Sheet. We find that in order to reconcile differences between model predictions and RSL evidence, a thick, spatially extensive ice sheet of ～600–700 m over much of north and central Ireland is required at the LGM with very rapid deglaciation after 21 k cal. yr BP. Copyright © 2007 John Wiley & Sons, Ltd.     

Introduction to special issue on connectivity in water and sediment dynamics

Connectivity has emerged in recent years as a significant conceptual framework within which to address the spatial and temporal variability in runoff and sediment transport. This special issue draws together several of the papers that were presented in the session “Connectivity in water and sediment dynamics: how do we move forwards?” at the 2012 General Assembly of the European Geosciences Union in Vienna, Austria. The papers submitted for this special issue fall into three groups: empirical studies, modelling studies, and conceptual development. Although it may be evident that the concept of connectivity helps us to express the complexity (in terms of water and sediment yields) of landscape responses to rainfall inputs, does it improve our ability to understand or predict those responses? There would still seem to be some way to go in connectivity research before this nagging concern can be assuaged. That it can be will undoubtedly be an important task for a number of ongoing research initiatives. Copyright © 2015 John Wiley & Sons, Ltd.     

The use of RFID in soil‐erosion research

In this paper, we examine the use of radio frequency identification (RFID) tags for studying soil erosion. Surrogate soil particles were created by coating RFID tags with silicone clay and bronze powder to give them an overall density similar to that of quartz particles. The particles were between 2.5 mm and 4.0 mm in diameter and had specific weights of 2.5 to 3.0. These tagged particles were deployed on two plots: first, in a proof‐of‐concept laboratory study and secondly in a field study, the latter involving repeated surveys after rainfall events. Seven surveys under natural rainfall over four months yielded recovery rates averaged 56%. RFIDs are shown to provide useful insights into the movement of individual soil particles during erosion processes. As RFID technology advances, further miniaturization is likely to occur enabling the movement of a greater range of soil particles to be studied, and we may anticipate improvements to the signal detection so that recovery does not rely wholly on visual identification. Copyright © 2014 John Wiley & Sons, Ltd.     

Integration of neural networks and cellular automata for urban planning

This paper presents a new type of cellular automata (CA) model for the simulation of alternative land development using neural networks for urban planning. CA models can be regarded as a planning tool because they can generate alternative urban growth. Alternative development patterns can be formed by using different sets of parameter values in CA simulation. A critical issue is how to define parameter values for realistic and idealized simulation. This paper demonstrates that neural networks can simplify CA models but generate more plausible results. The simulation is based on a simple three-layer network with an output neuron to generate conversion probability. No transition rules are required for the simulation. Parameter values are automatically obtained from the training of network by using satellite remote sensing data. Original training data can be assessed and modified according to planning objectives. Alternative urban patterns can be easily formulated by using the modified training data sets rather than changing the model.     

Earthquake early warning scenarios at critical facilities in the Eastern Caribbean

A feasibility study of an earthquake early warning (EEW) system was conducted for the Eastern Caribbean region using scenario earthquakes, corresponding to the maximum credible earthquakes and to the earthquakes associated with a return period of 475 years. Broadband synthetic seismograms were produced at selected critical facilities, where there is potential interest in the installation of an EEW system. The expected damage was derived from the synthetic seismograms and compared with the lead-time determined for both a regional and on-site EEW configuration. Next, the Virtual Seismologist EEW algorithm, as included in SeisComP3, was tested. Additional broadband synthetic seismograms were produced for the stations in the Eastern Caribbean seismic networks in order to simulate the real time behaviour of the seismic networks during the occurrence of the synthetic earthquakes and to assess the predictive capacity of the selected ground motion prediction equation. Expected peak ground parameters and lead-times at the critical facilities constitute the major outcome of the study.     

中国生产性服务业发展与空间分布

从分行业的角度探讨了中国生产性服务业的发展特征及其在城市体系中的空间分布。研究表明,中国生产性服务业的发展水平还处在初级阶段,虽然高级别生产性服务业增长较快,但是所占比重较小。空间分布上,生产性服务业倾向于集中在特大城市。由于其在经济发展中发挥重要的作用,这种分布特征重组了城市等级结构和城市之间的经济联系。随着中国经济的持续增长和政府的政策支持,对生产性服务业的需求将大大增加。全球化背景下,发展生产性服务业也成为重要的城市发展战略。但是,生产性服务业不均衡的分布格局决定了大城市和特大城市在新一轮的城市发展中具有更大的竞争力。因此,中小城市在发展生产性服务业时必须进行深入的分析,以免造成用地和资金的浪费。