Crisis information distribution on Twitter: a content analysis of tweets during Hurricane Sandy

Social media has been widely used for crisis communication during disasters, and its use during extreme events has drawn attention from both researchers and practitioners. Although crisis information coverage and distribution speed are important issues, both have not been studied extensively in the literature. This paper fills this gap by studying information distribution and coverage of social media during disasters. To this end, we searched and analyzed 986,579 tweets posted during Hurricane Sandy (October 22 to November 6, 2012). To learn about responses from official agents, we sampled 163 governmental organizations (GO), 31 non-governmental organizations (NGO) and 276 news agent accounts and their tweets for analysis. Specifically, five social media key performance indicators (KPIs) are studied in this paper, including impression, like, mention, re-tweet, and response time, and other variables such as hashtag, tweet frequency, and information type. We also test whether the five KPIs and other variables are different among different user types. Results show that total impression, re-tweet rate, hashtag, and tweet frequency are significantly \((P<0.05)\) different among different user types. Specifically, although news agent users generate a larger number of total impressions and tweet more frequently than GO and NGO users, their re-tweet rates and number of hashtags are lower than the GO and NGO users. Re-tweet rate based on mentioned users (5%) is significantly higher \((P=0.00)\) than that based on regular followers (0.01%). Nearly 89% of total impressions are generated from regular followers, with impressions from re-tweeting being a minority. This paper provides some new insights into how social media was used for crisis communication during disasters.     

A review of flood damage analysis for a building structure and contents

Natural Hazards - As a natural hazard, flood can cause a significant damage to buildings. Buildings are one of the important components of an economy which are providing the necessary space for...     

Attachment to the residential neighbourhood: a framework for analysis

There is an abundance of literature on attachment to the residential neighbourhood and satisfaction with it. Efforts to explain variation in such attachment emphasise the relevance of population characteristics to the neglect of factors affecting attachment which are external to the neighbourhood's population. This article suggests a wide framework for analysis. The suggestion is made that a hierarchy of neighbourhood contexts could be used in order to reach a more complete explanation and understanding of attachment and variation in it to the residential neighbourhood.     

Two-dimensional modeling of flood wave propagation in residential areas after a dam break with application of diffusive and dynamic wave approaches

Natural Hazards - In this study, a two-dimensional hydraulic routing model was applied to a sudden failure scenario for the Atasu Dam in Trabzon, Turkey. The goal was to simulate spreading and...     

Lung cancer risk associated with residential proximity to industrial installations: a spatial analysis

Lung cancer is the most common cause of cancer-related death and thus a major public health problem. While lung cancer frequency might be partially attributable to smoking habit and occupational exposure, the role of industrial pollution also needs to be assessed. To ascertain the possible effect of residential proximity to industrial installations on lung cancer risk in Asturias, an industrial region in Spain, taking into account the type of industrial activity and carcinogenic substances released. We conducted a hospital-based case–control study covering 700 lung cancer patients and 700 controls recruited in Asturias, matched individually by ethnicity, hospital, age, and sex. Distances were computed from the respective participants’ residential locations to the 48 industrial facilities governed by the Integrated Pollution Prevention and Control Act 16/2002 and included in the European Pollutant Release and Transfer Register, and located in the study areas. Using logistic regression, odds ratios (ORs) and 95 % confidence intervals (95 % CIs) were calculated and adjusted for sex, age, hospital area, tobacco consumption, family history of cancer, area of residence, and occupation. Excess risk of lung cancer was observed for individuals living near industrial installations (OR = 1.43; 95 % CI = 1.08–1.89), particularly metal industries (OR = 1.40; 95 % CI = 1.05–1.87), cement plants (OR = 4.81; 95 % CI = 1.20–19.19), and shipyards (OR = 1.69; 95 % CI = 1.17–2.43). Residents living close to industrial facilities releasing dioxins displayed a high, though non-statistically significant, excess risk of lung cancer (OR = 1.62; 95 % CI = 0.86–3.07). This study suggests a possible association between lung cancer risk and proximity to industrial installations, specifically metal industries, cement plants, and shipyards.     

Groundwater recharge in irrigated semi-arid areas: quantitative hydrological modelling and sensitivity analysis

For semi-arid regions, methods of assessing aquifer recharge usually consider the potential evapotranspiration. Actual evapotranspiration rates can be below potential rates for long periods of time, even in irrigated systems. Accurate estimations of aquifer recharge in semi-arid areas under irrigated agriculture are essential for sustainable water-resources management. A method to estimate aquifer recharge from irrigated farmland has been tested. The water-balance-modelling approach was based on VisualBALAN v. 2.0, a computer code that simulates water balance in the soil, vadose zone and aquifer. The study was carried out in the Campo de Cartagena (SE Spain) in the period 1999–2008 for three different groups of crops: annual row crops (lettuce and melon), perennial vegetables (artichoke) and fruit trees (citrus). Computed mean-annual-recharge values (from irrigation+precipitation) during the study period were 397 mm for annual row crops, 201 mm for perennial vegetables and 194 mm for fruit trees: 31.4, 20.7 and 20.5% of the total applied water, respectively. The effects of rainfall events on the final recharge were clearly observed, due to the continuously high water content in soil which facilitated the infiltration process. A sensitivity analysis to assess the reliability and uncertainty of recharge estimations was carried out.     

Linking multi-temporal analysis and community consultation to evaluate the response to the impact of Hurricane Stan in coffee areas of Chiapas,Mexico

This paper analyses the responses related to land use of coffee growers in Chiapas, Mexico to the impact of Hurricane Stan (October 2005). A multi-temporal analysis of the effect on land cover was performed through the combination of unsupervised classification of SPOT multispectral images and visual interpretation of panchromatic images (8 months previous to the hurricane, and 2, 14, and 40 months after the hurricane). The information provided by this geographic analysis was interpreted in light of information gathered though household surveys. Although the hurricane wrecked havoc across the region, the main impact in the study area was in the riparian zones where the extent of the loss experienced in terms of coffee harvest and soil was such that, even 14 months after the event, households with land in those areas were struggling to recover. Nevertheless, after 40 months, the zones that had suffered total soil loss began to support soil and vegetation, indicating the possibility of replanting coffee in those areas. Although the hurricane occurred when the coffee sector was particularly fragile as a result of the preceding several years of poor prices, the impact did not trigger extensive land use change. The surveys showed, however, that people are now more informed of the risk of living and farming on the river margins and are now performing soil conservation practices and planting trees to reduce risk.     

Understanding a coastal flood event: the 10th March 2008 storm surge event in the Solent, UK

Extreme sea-level events (e.g. caused by storm surges) can cause coastal flooding, and considerable disruption and damage. To understand the impacts or hazards expected by different sea levels, waves and defence failures, it is useful to monitor and analyse coastal flood events, including generating numerical simulations of floodplain inundation. Ideally, any such modelling should be calibrated and validated using information recorded during real events, which can also add plausibility to synthetic flood event simulations. However, such data are rarely compiled for coastal floods. This paper demonstrates the capture of such a flood event dataset, and its integration with defence and floodplain modelling to reconstruct, archive and better understand the regional impacts of the event. The case-study event comprised a significant storm surge, high tide and waves in the English Channel on 10 March 2008, which resulted in flooding in at least 37 distinct areas across the Solent, UK (mainly due to overflow and outflanking of defences). The land area flooded may have exceeded 7 km², with the breaching of a shingle barrier at Selsey contributing to up to 90 % of this area. Whilst sea floods are common in the Solent, this is the first regional dataset on flood extent. The compilation of data for the validation of coastal inundation modelling is discussed, and the implications for the analysis of future coastal flooding threats to population, business and infrastructure in the region.     

The expansion of offices into residential areas: Organized social protest in a threatened neighborhood

There have been many studies of changes in the distribution of offices in large cities, discussing the relative decline of the share of office space in central business districts and the movement of offices both to residential areas on the margins of the central business district and further out into the suburbs. The present article does not discuss the process itself but rather neighborhood reaction against the penetration of offices into residential areas, taking up the specific case of the Rehavia neighborhood of Jerusalem, a prestigious area on the margins of the central business district, into which a large number of offices have moved in recent years. The residents of Rehavia have organized to halt the process and diminish its intensity. This social reaction is of great importance, for it reflects the conflicting demands of development and preserving the character of inner urban neighborhoods.     

Compliance with land use regulations in peri-urban areas in Ghana: a study of Bamahu and Danko residential areas in Wa municipality,Upper West Region

GeoJournal - Globally, there is a sharp increase in human population in urban areas resulting to competition for land for settlement. With pressure on urban land, compliance with land use planning...     

An operational framework for communicating flood warnings to indigenous farmers in southern Nigeria: a systems thinking analysis

GeoJournal - In March 2012, the Nigerian meteorological agency forecasted massive flooding for parts of the country, with the displacement of large parts of the population as a consequence. Delta...     

Tropical cyclone risk perceptions in Darwin,Australia: a comparison of different residential groups

Different individuals and groups perceive risk differently. This can significantly affect risk management and mitigation practices and requirements. This paper presents findings from a study of tropical cyclone risk perceptions in the city of Darwin in the Northern Territory of Australia. Primary in-depth interview data and other secondary data are analysed, focussing in particular on wind damage, storm surge and life safety risk perceptions of residents since Cyclone Tracy, which impacted in 1974, and perceptions of future climate change as it relates to tropical cyclone risk. The analysis reveals that a number of perceptions prevail. In particular, the study reveals a wide difference of perceptions between short-term residents (Group 1) and long-term and expert residents (Group 2) in relation to wind damage, storm surge and life safety risk. It also reveals a large division between laypersons (Group 3) and expert residents’ (Group 4) perceptions of climate change risk as it relates to tropical cyclone risk. The author recommends that flexible, multiple and integrative management and mitigation approaches are required to deal with such different perceptions and divisions in the resident population.