Regional effects of natural disasters in China: investing in post-disaster recovery

We examine the effects of natural disasters on income and investment in China. Using macroeconomic province-level data and the provincial history of disaster exposure over the past two decades, we describe the relationship between disaster mortality and morbidity, disasters’ economic damages, government investment and regional economic activity, and infrastructure development. The Chinese government’s aggressive investment in post-disaster reconstruction is discussed, and the implications of this investment for post-disaster private sector economic activity are analyzed empirically. We further investigate the differential effects of natural disasters on economic activity in China’s diverse geographical regions.

     

Interaction of a compressional impulse with a slot normal to the surface of an elastic half space – II

Summary. An improved finite difference scheme has been used to simulate the propagation of a plane P -impulse in an elastic half space with a slot normal to its surface. Various angles of incidence and dimensions of slot are considered. The numerical results are presented in several visualizations; each emphasized a different type of wave and all representations help in understanding the scattered and diffracted wave pattern. Experiments were carried out using 0.5—6 MHz ultrasonic pulses on a duralumin semidisc with a surface-breaking slot and the results are compared with those given by the numerical models.
The scattered wavefield includes compressional and Rayleigh pulses whose amplitude increases at the front of the slot and decreases behind it, as the angle of incidence is reduced. A diffracted compressional pulse is generated with a semicircular wavefront centred at the mid-point of the bottom of the slot. Also, two elliptical eddies are excited at the lower corners. These ellipses propagate into the medium and eventually spread out to form arc-shaped shear pulses.
In the shadow zone, behind the slot, the two components of displacement show independent behaviour. The horizontal component decreases either with decreasing angle of incidence or as the slot is made deeper. For acute angles, a reduction of displacement amplitude of about 50 per cent is obtained when the depth of the slot is made a half pulse width. On the other hand there is no diminution of the vertical displacement behind the slot, and, near the upper right corner, it is even amplified.     

Interaction of a compressional impulse with a slot normal to the surface of an elastic half space

Summary. An improved finite difference scheme is applied to simulate wave propagation in the vicinity of a slot normal to the surface of an elastic half space. It provides visualization of the scattered wave pattern at a sequence of time steps, and also the components of displacement as functions of time at a series of observation points.
After being hit by a normally incident plane P pulse, the slot oscillates with two main cycles and two shear-compressional pairs of diffracted waves, and also Rayleigh pulses, are scattered from it. The resulting wavefronts are parallel to the vertical surfaces of the slot and curve in semicircular arcs around the bottom of the slot.
Experimental tests of the theory were performed, using 0.5–6 MHz ultrasonic pulses on duralumin cylinders with surface-breaking slots ranging from 0.5–2 mm in width and from 2–6 mm in depth. The numerical results were confirmed by these experiments.     

Mainstream,Inclusionary, and Convivial Places: Locating Encounters Between People with and Without Intellectual Disabilities

Convivial encounters, where strangers experience temporary shared identification with each other, are valorised in recent literature for their transformative potential. For people with intellectual disabilities, encounters with strangers are an important aspect of social inclusion, and opportunities to become recognised and known within their communities. This paper considers the question of what places are most conducive for convivial encounters between people with and without disabilities. The paper draws on findings from a study conducted in the State of Victoria, Australia, that involved ethnographic observations of encounters between people with and without intellectual disabilities, as well as a survey and face‐to‐face interviews with people with intellectual disabilities, their support workers and neighbours. The discussion is framed around two broad categories of place, mainstream and specialist, which have the potential to be inclusive and convivial.     

Reflections on use of participatory research for disaster risk reduction

Participatory research approaches are increasingly popular with academic researchers and development organisations working to facilitate change in collaboration with local communities. This paper contributes to recent debates over the use of participatory approaches by examining the use of participatory research within disaster risk reduction. Drawing on research in Papua New Guinea in which participatory techniques were used with indigenous communities to determine strategies for dealing with environmental hazards, the value of such techniques is critiqued. Finally the significance of participatory research as a research methodology is discussed as is its possible contribution to disaster risk reduction policy.     

Barnacle fouling in the Mediterranean sponges Axinella polypoides and Axinella verrucosa

Secondary metabolites protect many marine sponges (Phylum: Porifera) from settlement by fouling organisms. Previous studies on the subtidal demosponge Axinella verrucosa collected in the Western Mediterranean led to the isolation of compounds that inhibited the settlement of cyprids larvae of the intertidal barnacle Balanus amphitrite, and the enzyme chitinase, which plays a key role in the molting cycle of crustaceans. However, in a field survey conducted at three locations in Israel, Eastern Mediterranean Sea, we observed that A. verrucosa is fouled by the subtidal barnacle Balanus trigonus, a previously unknown association. Settlement inhibition assays using B. amphitrite with chemical extracts from Israeli A. verrucosa and Axinella polypoides, a sympatric, congeneric sponge that seems not to be fouled by B. trigonus, showed that cyprid larvae of B. amphitrite were inhibited by the extracts of both sponges from settlement at concentrations several magnitudes lower than natural volumetric extract concentration in the sponges. These results indicate that, unlike the intertidal barnacle B. amphitrite, the subtidal B. trigonus is unaffected by the compounds from A. verrucosa, stressing and underlining the importance of using suitable target organisms (i.e. from the same habitat) to test for ecologically relevant antifouling activities.     

An overview of flood actions on buildings

This paper presents an overview of flood characteristics with respect to their applicability for estimating and analysing direct flood damage to buildings. The approach taken is to define “flood actions” as acts which a flood could directly do to a building, potentially causing damage or failure. This definition expands the traditional approach of analysing flood damage to buildings which often focuses on damage from slow-rise flood depth.

Flood actions may be energy transfers, forces, pressures, or the consequences of water or contaminant contact. This paper defines and categorises flood actions on buildings, indicating methods of quantification. The actions are classified in the following categories with respect to relative importance for flood damage assessment.

• High relevance and relatively predictable: Lateral pressure from water depth differential between the inside and outside of a building, lateral pressure from water velocity, and water contact due to slow-rise depth.

• Relevance varies and relatively predictable: Buoyancy.

• Relevance varies and difficult predictability: Capillary rise, erosion, debris, turbulence, waves, other velocity actions, other chemical actions, nuclear actions, and biological actions.

Due to the highly localised effects of some of the flood actions in the third category, coupled with their potentially significant impact, prediction of their impact on overall flood damage may be challenging. Awareness of their existence assists in developing an understanding of the uncertainties in flood damage estimation and analysis and in indicating areas which new research should tackle. In particular, work is needed in order to fully understand the physical processes by which flood damage arises and, hence, how flood damage may be prevented.