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In this paper, we developed a score-based credibility assessment model which assesses the credibility of text and map-based VGI. We proposed parameters for assessing the credibility of VGI such as distance, hazard, and clustering. Then, the model was created based on the above-mentioned parameters, and the credibility scores of reports were computed. Furthermore, we categorized the reports into high-credible and low-credible categories, and accuracy of the model was determined by comparing the model's output with the real situation. To assess the credibility of VGI, we made use of reports from the Ushahidi project in Brisbane, Australia, which was hit by a severe flood in 2013 as our first dataset. Besides the aforementioned parameters, we examined the distance between the location of the user and location of the incident as a parameter for the credibility assessment of VGI. For doing so, in a case study, we developed a VGI-based website to collect data for the analysis. Results show that our model which was created by spatial clustering and flood hazard parameters can categorize the credibility classes with 92.6% accuracy. In addition, in the second study area, the credibility model using the proximity of the volunteer to the incident site parameter can assess the credibility classes of VGI with 90% accuracy. [ABSTRACT FROM AUTHOR]

Floods are the most common and destructive disasters around the globe, which becomes more challenging in coastal areas due to higher population density and catchment areas relative to floods in an inland area. For effective coastal flood management to reduce flood adverse impacts it is necessary to investigate the flooding processes and their joint interaction in a coastal area. This paper selected the Brisbane River Estuary, Australia as an example, and the MIKE 21 model is applied to investigate the effects of mesh resolution on the flood discharge and to explores compound flooding by computing variances in coastal flood assessments resulting from a separation of tidal and riverine processes. The statistical results showed that the Nash-Sutcliffe coefficient, E of water level are varied from 0.84 to 0.95 and the model simulated the 2011 flood extent results agreed with 90 % accuracy with the observed flood extent. Five mesh resolutions cases were analyzed and the result found that the finer mesh resolution Case 5 was more appropriate for calculating the peak discharge with 2.7 % with estimated discharge. Compound flood event simulation results emphasized that not considering the interaction of various flooding drivers caused 0.62 m and 0.12 m reduction in the flood levels at Jindalee and Brisbane city gauges, and uncertainties in flood extent. Simulated results of flood at Brisbane city gauge, showed that 2011 and 2013 floods with storm surge scenario 4 demonstrate, the increase in flood level to be 12 % and 34 % respectively. The results recommend flooding assessment by using mesh convergence with joint probability of compound flood under future storm surge for planning and management of coastal projects. [ABSTRACT FROM AUTHOR]

The study of archaeological site formation processes, although routinely undertaken for prehistoric sites, is only carried out in historical archaeology in a limited way. Understanding the processes which formed the archaeological record of a site is an important first step towards developing justifiable inferences about past behavior and past societies regardless of the age of the site. This paper identifies and examines the cultural and non-cultural processes that formed the archaeological record at the Commissariat Store, Brisbane. The history of the site, from its construction in 1829 as part of the Moreton Bay penal settlement to the present, is examined and the expected impacts and processes on the archaeological record are identified. Archaeological evidence from the salvage excavation of the site undertaken in 1978 and 1979 is analyzed to identify the cultural and non-cultural site formation processes. This study identifies the presence of cultural formation processes including discard, loss, abandonment and re-use from an examination of the historical and archaeological evidence. Non-cultural formation processes at work in the site include faunalturbation, floralturbation, flooding, and aquaturbation. [ABSTRACT FROM AUTHOR]

In the Australian summer season of 2022, exceptional rainfall events occurred in Southeast Queensland and parts of New South Wales, leading to extensive flooding of rural and urban areas. Here, we map the extent of flooding in the city of Brisbane and evaluate the change in electricity usage as a proxy for flood impact using VIIRS nighttime brightness imagery. Scanning a wide range of possible sensors, we used pre-flood and peak-flood PlanetScope imagery to map the inundated areas, using a new spectral index we developed, the Normalized Difference Inundation Index (NDII), which is based on changes in the NIR reflectance due to sediment-laden flood waters. We compared the Capella-Space X-band/HH imaging radar data captured at peak-flood date to the PlanetScope-derived mapping of the inundated areas. We found that in the Capella-Space image, significant flooded areas identified in PlanetScope imagery were omitted. These omission errors may be partly explained by the use of a single-date radar image, by the X-band, which is partly scattered by tree canopy, and by the SAR look angle under which flooded streets may be blocked from the view of the satellite. Using VIIRS nightly imagery, we were able to identify grid cells where electricity usage was impacted due to the floods. These changes in nighttime brightness matched both the inundated areas mapped via PlanetScope data as well as areas corresponding with decreased electricity loads reported by the regional electricity supplier. Altogether we demonstrate that using a variety of optical and radar sensors, as well as nighttime and daytime sensors, enable us to overcome data gaps and better understand the impact of flood events. We also emphasize the importance of high temporal revisit times (at least twice daily) to more accurately monitor flood events. [ABSTRACT FROM AUTHOR]

There is a growing need to introduce warning dissemination systems in disaster-prone regions to improve the coverage of information distribution. In this study, a warning dissemination system was designed in which disaster information transmitted by a global navigation satellite system (GNSS) is received by terrestrial infrastructure, such as sirens and public transportation, converted into audio messages, and delivered automatically. The originality of the designed system lies in its appropriate integration of existing satellite systems and terrestrial infrastructure, making the system potentially applicable in many regions. First, we evaluated the effectiveness of the designed system in distributing audio messages using public buses in Brisbane, Australia, where large floods occur frequently. Real-time location information for public buses was acquired in the format of General Transit Feed Specification (GTFS), which is currently used in many countries. Time-series changes in the coverage rate relative to both the flood inundation zone and population were calculated using a geographic information system (GIS). The simulation results showed that the system could reach 60% of the flood inundation zone and 70% of the population on a holiday, indicating that the designed system could be effectively adapted to the target area. The coverage rate was found to peak during 15:00–16:00, with minimum rates observed late at night and early in the morning. These results will allow the development of an effective disaster management plan. In the future, this system will be evaluated in other regions using the same calculation process. [ABSTRACT FROM AUTHOR]

This study examines an innovative Coastal Reservoir (CR) technique as a feasible solution for flood adaptation and mitigation in the Brisbane River Estuary (BRE), Australia, which is vulnerable to coastal flooding. The study analysed the operation of a CR by using the MIKE 21 hydrodynamic modelling package. The 2D hydrodynamic model was calibrated and validated for the 2013 and 2011 flood events respectively, with a Nash-Sutcliffe coefficient (Ens) between 0.87 to 0.97 at all gauges. River right branch widening and dredging produced a 0.16 m reduction in water level at the Brisbane city gauge. The results show that by suitable gate operation of CR, the 2011 flood normal observed level of 4.46 m, with reference to the Australian Height Datum (AHD) at Brisbane city, could have been reduced to 3.88 m AHD, while under the improved management operation of the Wivenhoe Dam, the flood level could be lowered to 4 m AHD at Brisbane city, which could have been reduced with CR to 2.87 m AHD with an overall water level reduction below the maximum flood level. The results demonstrated that the innovative use of a CR could considerably decrease the overall flood peak and lessen flood severity in the coastal city of Brisbane. [ABSTRACT FROM AUTHOR]