Understanding Climatic Impacts, Vulnerabilities, and Adaptation in the United States: Building a Capacity for Assessment

Based on the experience of the U.S. National Assessment, we propose a program of research and analysis to advance capability for assessment of climate impacts, vulnerabilities, and adaptation options. We identify specific priorities for scientific research on the responses of ecological and socioeconomic systems to climate and other stresses; for improvement in the climatic inputs to impact assessments; and for further development of assessment methods to improve their practical utility to decision-makers. Finally, we propose a new institutional model for assessment, based principally on regional efforts that integrate observations, research, data, applications, and assessment on climate and linked environmental-change issues. The proposed program will require effective collaboration between scientists, resource managers, and other stakeholders, all of whose expertise is needed to define and prioritize key regional issues, characterize relevant uncertainties, and assess potential responses. While both scientifically and organizationally challenging, such an integrated program holds the best promise of advancing our capacity to manage resources and the economy adaptively under a changing climate.     

Response of single benthic metrics and multi-metric methods to anthropogenic pressure gradients, in five distinct European coastal and transitional ecosystems

In recent times many benthic indices have been proposed to assess the ecological quality of marine waters worldwide. In this study we compared single metrics and multi-metric methods to assess coastal and transitional benthic status along human pressure gradients in five distinct environments across Europe: Varna bay and lake (Bulgaria), Lesina lagoon (Italy), Mondego estuary (Portugal), Basque coast (Spain) and Oslofjord (Norway). Hence, 13 single metrics (abundance, number of taxa, and several diversity and sensitivity indices) and eight of the most common indices used within the European Water Framework Directive (WFD) for benthic assessment were selected: index of size spectra (ISS), Benthic assessment tool (BAT), Norwegian quality index (NQI), Multivariate AMBI (M-AMBI), Benthic quality index (BQI), (Benthic ecosystem quality index (BEQI), Benthic index based on taxonomic sufficiency (BITS), and infaunal quality index (IQI). Within each system, sampling sites were ordered in an increasing pressure gradient according to a preliminary classification based on professional judgement. The different indices are largely consistent in their response to pressure gradient, except in some particular cases (i.e. BITS, in all cases, or ISS when a low number of individuals is present). Inconsistencies between indicator responses were most pronounced in transitional waters (i.e. IQI, BEQI), highlighting the difficulties of the generic application of indicators to all marine, estuarine and lagoonal environments. However, some of the single (i.e. ecological groups approach, diversity, richness) and multi-metric methods (i.e. BAT, M-AMBI, NQI) were able to detect such gradients both in transitional and coastal environments, being these multi-metric methods more consistent in the detection than single indices. This study highlights the importance of survey design and good reference conditions for some indicators. The agreement observed between different methodologies and their ability to detect quality trends across distinct environments constitutes a promising result for the implementation of the WFD’s monitoring plans. Moreover, these results have management implications, regarding the dangers of misclassification, uncertainty in the assessment, use of conflicting indices, and testing and validation of indices.     

22. Wandlungen des Holzes auf dem Weg zur Kohle

Ohne ZusammenfassungErweiterte Veröffentlichung des gleichnamigen Vortrags auf der Tagung der Geologischen Vereinigung, Frankfurt a. M., 9. Januar 1938.     

The Portuguese bend landslide

The Portuguese Bend landslide, in coastal southern California, is an active, slow-moving mass of blocks and debris that extends from the shoreline to moderate altitudes along part of the southerly margin of the Palos Verdes Hills. These hills form a peninsula that is underlain by Cenozoic sedimentary and volcanic rocks draped anticlinally over a core of Mesozoic schist. In the southerly parts of the peninsula, inherently weak units in the Altamira Shale Member of the Miocene Monterey Formation dip seaward in general concordance with the ground surface. Ground failure has been widespread in this area. It evidently began in mid- to late-Pleistocene time, and it has continued intermittently to the present.

The Portuguese Bend landslide represents a reactivation of movement of the eastern part of a complex of prehistoric landslides occupying an area of approximately two square miles. This latest episode of movement began in 1956, presumably in response to placement of fill during a road construction project. The active slide subsequently was enlarged by sequential failure of adjoining blocks of ground, and by September 1969 about 54,500,000 metric tons of debris was slowly moving downslope in an area of approximately 104 ha. Movement has been continuous since recent failure began in 1956, although the velocity of the active slide decreased markedly after that year. Between 1962 and 1972 the velocity fluctuated only slightly about an average value of about 1 cm per day.

The active slide is an irregular prism, roughly triangular in plan view. The southern side of the triangle trends approximately 1100 m east-west along a stretch of shoreline that essentially coincides with the toe of the slide. The other two sides of the triangle trend northeast and northwest from the ends of the toe and meet about 1200 m north of the shoreline. The thickness of the moving mass differs considerably from one place to another, reflecting both topographic irregularities and major undulations in the underlying surface of movement. The maximum thickness is approximately 75 m.

Movement is occurring along a distinct basal failure surface. The eastern part of the slide is underlain by bedrock, and is bordered by bedrock with a general structure that limits further deep-seated propagation of failure to the east and northeast. In contrast, the western part of the slide is underlain and bordered by extensive ancient landslide deposits that are marginally stable. Further encroachment of the active slide westward and northwestward into these materials was viewed as a distinct possibility at the time the dissertation was prepared and has occurred since then.

Continued movement of the Portuguese Bend landslide since 1956 has been due to four main factors. A rise in the water table during the period 1957–1968 has been documented in the northwestern part of the moving mass and is attributable mainly to infiltration of surface runoff entering numerous open fissures that cut the surface of the slide. The toe of the active slide daylights along the shoreline and is subjected to storm-wave erosion, so that any natural build-up of resisting forces is prevented in this area. The redistribution of mass as the slide has moved along an undulatory failure surface has been responsible for local fluctuations in the driving and resisting forces. Finally, smoothing of irregularities in the failure surface by the moving slide mass must have decreased some of the forces resisting movement.