U32B-01 INVITED
Extreme events: Some theoretical and practical considerations
Predictive understanding of how extreme events arise is an important goal of the natural sciences that is tightly connected with adaptation and mitigation of natural hazards. This talk reports first on selected results from a highly interdisciplinary, multi-national, European-Union sponsored project on "Extreme Events: Causes and Consequences (E2-C2)." These results will include some of the more practical aspects of extreme events and natural hazards. Second, it reports on preliminary results about the key mechanisms that generate extreme events in nonlinear, periodically driven systems with a delayed feedback. Toy models of this type were shown to capture major features of the El Nino-Southern Oscillation (ENSO) phenomenon [Jin et al., Science, 1994; Tziperman et al., Science, 1994]; they may be relevant to other natural systems in which internal instabilities interact with external forcing and give rise to extreme events. We focus here on a one-dimensional differential- delay model with a single delay and periodic forcing. This simple model is characterized by unstable solutions in a broad range of parameters, and we describe the mechanisms of the observed instabilities, connect our findings to climate phenomena, and formulate questions for further theoretical and numerical analysis. We report on two classes of instability: one prevails at a small amplitude of the external forcing and is caused by frequency locking, as in the Devil's staircase scenario connected with ENSO already. The other one, more relevant for the applications of interest here, is seen at stronger external forcing and leads to abrupt overall changes in the solutions' behavior. These changes include the near-periodic appearance of extreme events (as in the observed warmings and coolings of the Tropical Pacific), as well as sudden changes of the mean (as in global climate shifts associated with rapid transitions between glaciated and ice-free Quaternary climates). The nature of these two types of instability will be analyzed and implications for the predictability of extreme events will be discussed.
U32B-02 INVITED
The economics of natural disasters
Mitigating natural disasters is probably more important for society than it can be inferred from direct losses. Total economic losses, indeed, can be much larger than direct losses, especially for large disasters, which affect the economy for extended periods of time (e.g., New Orleans after Katrina), and represent an important obstacle to economic development in certain regions (e.g. Central America). A series of recent modelling exercises highlights several findings. First, total economic losses due to an event are increasing nonlinearly as a function of its direct losses, because destructions both increase reconstruction needs and reduce reconstruction capacity. Second, endogenous economic dynamics has to be taken into account in the assessment of disaster consequences. More particularly, an economy in the expansion phase of its business cycle appears to be more vulnerable to extreme events than an economy in recession. This result is supported by the fact that worker availability is found to be one of the main obstacles to a rapid and efficient reconstruction. Third, natural disasters can create poverty traps for poor countries, which have a lower ability to fund and carry out reconstruction. As a consequence, climate change impacts from extreme events may be significant, and will depend on how societies are able to adapt their reconstruction capacity to new levels of risk.
U32B-03
Probabilistic Assessment of the Potential Impacts of Climate Variability and Change: An Illustration of Coffee Production in Veracruz.
The assessment of the potential impacts of climate change in productive activities has been limited to particular estimations that do not consider the inherent variability and uncertainty of climatic and socioeconomic variables. This approach can only provide a limited evaluation of risk under climate change conditions since it accounts only for changes in mean conditions and therefore it evaluates the mean impact. In this work Monte Carlo methods are utilized as a mean for approximating the probability density function of coffee production in Veracruz, Mexico and of the income of the average producer under 1) different climate change scenarios which include climate variability and uncertainty in economic variables; 2) uncertainty in climate change scenarios is added by means of normal and uniform probability distributions. Results show that for year 2050, depending on the emissions scenario, coffee production could diminish between a 22 and a 55% and production variability could increase as much as 266%. When uncertainty in climate change scenarios is included, probability distributions for production and income become less informative for decision-making and imply further reductions in their expected values and increases in their variability. Nevertheless, all production and income scenarios indicate that for the average producer this activity will become no longer profitable and that potential expected losses could become almost six times larger than in present conditions.
U32B-04
Challenges within Monitoring and Risk-Oriented Analysis of Precipitation- and Hydraulic- Coupled Catastrophic Rock- and Soil-Collapses at Urban and Infrastructural Alpine Areas
Within the past years we investigated several catastrophic soil- and rock-slides along infrastructural and urban
areas which are coupled to extreme weather phenomena. This contribution shall show examples, triggered by
catastrophic rain-falls and anthropogenic influence. Further, the stress-field between the compliance with legal
and economical requirements and the rising frequency of weather induced events shall be discussed from the
geoengineers point of view.
In the past, engineers were strictly confronted with the detailed geological and geomechanical or numerical
analysis of the slope failures. Since the past role of the engineer as inviolable decision leader is increasingly
weakened, due to economic control obligations - mostly operated from the far desk - new ways of conviction work
had to be developed as well as effective forecasting and monitoring instruments. For this reason the requirement
to engineers, regarding the ability to work multidisciplinary and to find more exact models, is risen, which is to be
seen positively.
In order to fulfill the increasing justification-requires when planning counter measures, several technical and
economical aspects are to be described quantitatively now. This quantitative description is the basis for risk-
analysis, which has to contain beside other aspects following:
a) The shift of the probability of extreme events
b) The expected harm at humans at the scenario put to reason
c) The expected damage at structures
d) The expected super-ordinate economical harm
e) The expected costs of counter-measure variants
f) The variant related residual risk, expressed in probable occurring costs
While the description of the first aspect a) is mainly a geotechnical challenge, which is connected to very detailed
knowledge of the slope-failure characteristic, triggering mechanisms as well as related historical and future
meteorological data, the aspects c) and e) concern exact technical cost investigations. The real challenges are
sensitive, ethical questions like the expression of the economical worth of a human life. But in order to be able to
perform and represent a true risk-calculation, beside performing intensive monitoring and forecasting one must
intensively explain the correct context regarding worth of life, in particular while representing measures or no
measures in front of persons, concerned by catastrophes.
In the currently contribution, case studies will be discussed were we were able to investigate and improve as well
the very basic data set, concerning extreme weather phenomena, geophysical monitoring of rock-slides, as well
as economical aspects and performed several multi-disciplinary monitoring projects, risk-oriented dynamic
investment calculations for countermeasures, considering also residual risks and their cost-related effects on
operators of infrastructure, individuals and the public.
http:www.alpinfra.com
U32B-05
Modeling Regional Economic Impacts of Natural Disasters
Common features of natural disasters are intense regional impacts and the need for assessing their economic impacts on the construction sectors. The years 2004 and 2005 were record-setting time for natural disasters with major disasters or catastrophic (Cat) events all around the world with dramatic consequences in human lives and economic losses around the world, affecting developed and developing countries. Although there is a large body of literature on assessing the impact of cat events, there is little available research on the quantification and modeling of the regional economic impact of such events on the cost and length of reconstruction. Current available econometric models have serious limitations because they need detailed information for modeling the complex interactions between the different stakeholders of the economy at a regional level that is generally not available. Also, very little research was performed for quantifying the demand surge, defined as the sudden increase in the cost of repairs due to amplified payments, following a hurricane or a series of hurricane events or other natural disasters. Demand surge is an important component of the overall economic impact of cat events and there is a need to better quantify it. This paper presents results of a research program that started after the 2004 and 2005 U.S. hurricane seasons. A large data set of economic and observed losses resulting from the hurricanes that affected Florida and the Gulf states in the US was collected at county level. This provided us with the basis for assessing the change in repair costs before and after these historical events, to quantify the demand surge (after removing the underlying baseline trends) at several dozens of locations across the areas affected, and to provide information on how the changes in demand surge vary spatially and temporally in affected areas for which the amount of structure losses were reported. A parallel research effort was undertaken for identifying and quantifying the main drivers behind the demand surge by conducting survey among the different stakeholders involved in the reconstruction. Results of this work were used for developing a relatively simple economic model that is dependent on information available at the county level that includes econometric metrics prior to the event and the losses following catastrophic events. These losses are either observed or modeled with physical models. The economic model was validated and tested with data collected from the 2004 and 2005 hurricanes. Historical reconstructions of economic losses from 1992 Andrew and other historical events were performed for different regions of the US. The goal is to develop an economic model that can include regional economic conditions at the time of the events for a better modeling of economic losses resulting from cat events that can be used for a better assessment of the risk.
U32B-06
Floods of 2005 in the State of Veracruz Book Presentation
During October of 2005, when hurricane Stan caused destruction to the center and south of the state of Veracruz, a book was elaborated. The book's called Floods of 2005 in the state of Veracruz and contains twenty chapters. The first three chapters conform a panoramic of the book and two historical and archaeological contributions. One second part takes care of the natural phenomena of floods: meteorological, hydrological aspects, and biodiversity. Economic and social aspects are the largest contents of the volume, which concludes with reflections towards the future: the possible consequences of global climatic change, the chemical component that's not considered in the evaluation and prevention of risks by hidrometeorogical phenomena, and the duty of political prevention of disasters. The frame reference for the book is through a discussion of all kind of contributions. Which means that this book presentation is for the geophysicists community of Mexico. Keywords: Floods, state of Veracruz, risks and disasters.
U32B-07
Democracy, GDP, and the Impact of Natural Disasters
In 1998 Amartya Sen won the Nobel Prize in economics for the observation that there has never been a famine in
a nation with a democratic form of government and a free press. We find that a similar relationship can be
demonstrated for all natural disasters. Data from the United Nations Food Programme and the United States
Office of Foreign Disaster Assistance is used to display strong correlations between the democracy index, GDP,
and the humanitarian impact of natural disasters. We find that nations in which disasters have high humanitarian
impact, approximated by lives lost, are also nations which are below the median per capita GDP and the median
democracy level. While the response to natural disasters varies from country to country, several additional global
trends are observed. Since 1964, the number of recorded natural disasters has increased by a factor of five.
During this same time period the number of deaths has decreased significantly. In particular, the humanitarian
impact of the 'typical' natural disaster has decreased by a factor of five. Post-disaster foreign aid is the common
response from the international community when a natural disaster strikes. Our study also compares the history
of foreign aid grants distributed by the US Office of Foreign Disaster Aid (OFDA) with the number of deaths
worldwide from natural disasters. We find that the amount of aid given is responsive to the degree of global
humanitarian impact.
http:www.princeton.edu/~abrett/Geo