The authors propose a new climatic drought index: the standardized precipitation evapotranspiration index (SPEI). The SPEI is based on precipitation and temperature data, and it has the advantage of combining multiscalar character with the capacity to include the effects of temperature variability on drought assessment. The procedure to calculate the index is detailed and involves a climatic water balance, the accumulation of deficit/surplus at different time scales, and adjustment to a log-logistic probability distribution. Mathematically, the SPEI is similar to the standardized precipitation index (SPI), but it includes the role of temperature. Because the SPEI is based on a water balance, it can be compared to the self-calibrated Palmer drought severity index (sc-PDSI). Time series of the three indices were compared for a set of observatories with different climate characteristics, located in different parts of the world. Under global warming conditions, only the sc-PDSI and SPEI identified an...

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A Multiscalar Drought Index Sensitive to Global Warming: The Standardized Precipitation Evapotranspiration Index

Two studies investigated the tendency of people to be unrealistically optimistic about future life events. In Study 1, 258 college students estimated how much their own chances of experiencing 42 events differed from the chances of their classmates. Overall, they rated their own chances to be above average for positive events and below average for negative events, ps<.001. Cognitive and motivational considerations led to predictions that degree of desirability, perceived probability, personal experience, perceived controllability, and stereotype salience would influence the amount of optimistic bias evoked by different events. All predictions were supported, although the pattern of effects differed for positive and negative events. Study 2 tested the idea that people are unrealistically optimistic because they focus on factors that improve their own chances of achieving desirable outcomes and fail to realize that others may have just as many factors in their favor. Students listed the factors that they thought influenced their own chances of experiencing eight future events. When such lists were read by a second group of students, the amount of unrealistic optimism shown by this second group for the same eight events decreased significantly, although it was not eliminated.

http://psych415.class.uic.edu/Readings/Weinstein,%20Unrealistic%20optimism,%20JPSP,%201980.pdf

Unrealistic optimism about future life events

This paper reviews the concept of adaptation of human communities to global changes, especially climate change, in the context of adaptive capacity and vulnerability. It focuses on scholarship that contributes to practical implementation of adaptations at the community scale. In numerous social science fields, adaptations are considered as responses to risks associated with the interaction of environmental hazards and human vulnerability or adaptive capacity. In the climate change field, adaptation analyses have been undertaken for several distinct purposes. Impact assessments assume adaptations to estimate damages to longer term climate scenarios with and without adjustments. Evaluations of specified adaptation options aim to identify preferred measures. Vulnerability indices seek to provide relative vulnerability scores for countries, regions or communities. The main purpose of participatory vulnerability assessments is to identify adaptation strategies that are feasible and practical in communities. The distinctive features of adaptation analyses with this purpose are outlined, and common elements of this approach are described. Practical adaptation initiatives tend to focus on risks that are already problematic, climate is considered together with other environmental and social stresses, and adaptations are mostly integrated or mainstreamed into other resource management, disaster preparedness and sustainable development programs. r 2006 Elsevier Ltd. All rights reserved.

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Adaptation, adaptive capacity and vulnerability

Global environmental change and sustainability science increasingly recognize the need to address the consequences of changes taking place in the structure and function of the biosphere. These changes raise questions such as: Who and what are vulnerable to the multiple environmental changes underway, and where? Research demonstrates that vulnerability is registered not by exposure to hazards (perturbations and stresses) alone but also resides in the sensitivity and resilience of the system experiencing such hazards. This recognition requires revisions and enlargements in the basic design of vulnerability assessments, including the capacity to treat coupled human–environment systems and those linkages within and without the systems that affect their vulnerability. A vulnerability framework for the assessment of coupled human–environment systems is presented.

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A framework for vulnerability analysis in sustainability science

There is considerable research interest on the meaning and measurement of resilience from a variety of research perspectives including those from the hazards/disasters and global change communities. The identification of standards and metrics for measuring disaster resilience is one of the challenges faced by local, state, and federal agencies, especially in the United States. This paper provides a new framework, the disaster resilience of place (DROP) model, designed to improve comparative assessments of disaster resilience at the local or community level. A candidate set of variables for implementing the model are also presented as a first step towards its implementation.

A place-based model for understanding community resilience to natural disasters

Strategies of American water management

The river systems of the world flow today with only a small proportion of their total volume harnessed and applied for human good. With the exception of a few small drainage basins in arid regions, the water of no stream has been fully regulated or used. There are physical limits to such regulation and use, but the degree to which those limits are approached is related to conditions which are partly technological, partly economic, partly political, and partly ethical. Using the concept of integrated river basin development, each major network of streams draining the land masses of the earth may be viewed as the backbone for a possible planned use of a unified system of multiple-purpose and related projects to promote regional growth. This view of river basin development has come, during the past sixty years, to be employed rather widely as a technical tool for achieving social change. It has found imaginative support, and it appears to be on the threshold of wider application. How much further it wisely may be applied would seem to depend, in part, upon sharpening of our knowledge as to its utility and implications as a tool. Like any tool, it is not inherently good. Its value must be judged in terms of the growth and changes it can effect and upon its flexibility and precision. The concept of river basin development is used here to mean three component ideas having separate roots in western civilization but coming to be associated with each other in present-day theory and practice. In addition, at least two other ideas have been related in varying circumstances, and it now is possible to suggest a definition of the tool on which there is relatively common agreement in practice. Before examining the evolution of that concept, it may be helpful to identify the broad limits to river basin development and the distinguishing characteristics of river systems. A. Limits and Degrees of Development Although the Nile and Tigris-Euphrates Valleys cradled the early civilizations of the eastern Mediterranean and still support their basic irrigation agriculture, and although the flows of the Rhine, the Ohio, and the Thames long have been essential to the industrialized populations along their banks, it would be inaccurate to regard

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A Perspective of River Basin Development

Drawers of water

No single resource development project has aroused more controversy than the high dam that stores the flow of the Nile River above the first cataract at Aswan. It is praised as the mainstay of the Egyptian economy and vilified as an environmental catastrophe. Twenty-one years after its completion there has been sufficient time to permit a first approximation of what is known about the dam's environmental effects and how they compare to what was anticipated when engineers and politicians decided to undertake the massive project. Although the evidence from post-audit study over the past decade is far from complete, there is enough to warrant general observations on direct economic impacts and to suggest several possible lessons of importance to scientists engaged in predicting and tracing environmental linkages from major water projects.

The Environmental Effects of the High Dam at Aswan

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Gilbert F. White

Papers

Strategies of American water management

A Perspective of River Basin Development

Drawers of water

The Environmental Effects of the High Dam at Aswan

The Choice of Use in Resource Management