Probabilistic GIS-based method for delineation of urban flooding risk hotspots   总被引：3，自引：1，他引：2  

Fatemeh Jalayer  Raffaele De Risi  Francesco De Paola  Maurizio Giugni  Gaetano Manfredi  Paolo Gasparini  Maria Elena Topa  Nebyou Yonas  Kumelachew Yeshitela  Alemu Nebebe  Gina Cavan  Sarah Lindley  Andreas Printz  Florian Renner 《Natural Hazards》2014,73(2):975-1001

Identifying urban flooding risk hotspots is one of the first steps in an integrated methodology for urban flood risk assessment and mitigation. This work employs three GIS-based frameworks for identifying urban flooding risk hotspots for residential buildings and urban corridors. This is done by overlaying a map of potentially flood-prone areas [estimated through the topographic wetness index (TWI)], a map of residential areas and urban corridors [extracted from a city-wide assessment of urban morphology types (UMT)], and a geo-spatial census dataset. A maximum likelihood method (MLE) is employed for estimating the threshold used for identifying the flood-prone areas (the TWI threshold) based on the inundation profiles calculated for various return periods within a given spatial window. Furthermore, Bayesian parameter estimation is employed in order to estimate the TWI threshold based on inundation profiles calculated for more than one spatial window. For different statistics of the TWI threshold (e.g. MLE estimate, 16th percentile, 50th percentile), the map of the potentially flood-prone areas is overlaid with the map of urban morphology units, identified as residential and urban corridors, in order to delineate the urban hotspots for both UMT. Moreover, information related to population density is integrated by overlaying geo-spatial census datasets in order to estimate the number of people affected by flooding. Differences in exposure characteristics have been assessed for a range of different residential types. As a demonstration, urban flooding risk hotspots are delineated for different percentiles of the TWI value for the city of Addis Ababa, Ethiopia.  相似文献   

Carbon capture and sequestration versus carbon capture utilisation and storage for enhanced oil recovery   总被引：1，自引：1，他引：0  

Bob Harrison  Gioia Falcone 《Acta Geotechnica》2014,9(1):29-38

There are 74 integrated carbon capture projects worldwide currently listed by the Global CCS Institute, including the few already running and those still at the identification, evaluation, definition or execution stage for operation by 2018. Significant funding programmes have recently been launched by the European Commission (NER300 in November 2011) and by the UK Department of Energy and Climate Change (CCS Commercialisation Programme in April 2012) for commercial demonstration projects leading to innovation across the CCS/CCUS technology chain to reduce energy system costs. In their calls for proposals, these programmes were open to both CCS and CCUS projects. However, there are significant technical and commercial differences between projects for enhanced oil recovery and those for permanent storage of carbon dioxide in saline aquifers or in depleted hydrocarbon reservoirs, the same way that there exist more complexities and limitations for offshore implementation. Such differences are accompanied by different levels of field verification of the various storage and utilisation concepts, with permanent sequestration having only a more recent history and smaller-scale implementation. In this scenario, the need for appropriate due diligence workflows and screening criteria to assess the technical viability and the deliverability of different CCS/CCUS projects remains crucial, vis-à-vis the high component costs, efficiency penalties, reservoir uncertainties and the many challenges related to full chain integration (from carbon dioxide capture to underground sequestration). Based on information in the public domain, this paper reviews the current status of offshore CCS/CCUS implementation worldwide and discusses screening criteria for use by governments, operators and investors alike.  相似文献   

Heavy ion reflection and heating by collisionless shocks in polar solar corona     

Gaetano Zimbardo 《Planetary and Space Science》2011,59(7):468-1498

We propose a new model for explaining the observations of preferential heating of heavy ions in the polar solar corona. We consider that a large number of small scale shock waves can be present in the solar corona, as suggested by recent observations of polar coronal jets by the Hinode and STEREO spacecraft. The heavy ion energization mechanism is, essentially, the ion reflection off supercritical quasi-perpendicular collisionless shocks in the corona and the subsequent acceleration by the motional electric field E=−(1/c)V ×B. The acceleration due to E is perpendicular to the magnetic field, giving rise to large temperature anisotropy with T_⊥?T_∥, which can excite ion cyclotron waves. Also, heating is more than mass proportional with respect to protons, because the heavy ion orbit is mostly upstream of the quasi-perpendicular shock foot. The observed temperature ratios between O⁵⁺ ions and protons in the polar corona, and between α particles and protons in the solar wind are easily recovered. We also discuss the mechanism of heavy ion reflection, which is based on ion gyration in the magnetic overshoot of the shock.  相似文献   

Alpha-effect current and kinetic helicities for magnetically driven turbulence and solar dynamo     

Gaetano Belvedere  V. V. Pipin  G. Rüdiger 《Journal of Astrophysics and Astronomy》2000,21(3-4):387-388

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A physics-based earthquake simulator and its application to seismic hazard assessment in Calabria (Southern Italy) region     

Rodolfo Console  Anna Nardi  Roberto Carluccio  Maura Murru  Giuseppe Falcone  Tom Parsons 《Acta Geophysica》2017,65(1):243-257

The use of a newly developed earthquake simulator has allowed the production of catalogs lasting 100 kyr and containing more than 100,000 events of magnitudes ≥4.5. The model of the fault system upon which we applied the simulator code was obtained from the DISS 3.2.0 database, selecting all the faults that are recognized on the Calabria region, for a total of 22 fault segments. The application of our simulation algorithm provides typical features in time, space and magnitude behavior of the seismicity, which can be compared with those of the real observations. The results of the physics-based simulator algorithm were compared with those obtained by an alternative method using a slip-rate balanced technique. Finally, as an example of a possible use of synthetic catalogs, an attenuation law has been applied to all the events reported in the synthetic catalog for the production of maps showing the exceedance probability of given values of PGA on the territory under investigation.  相似文献