Dynamics and Vulnerability of Delta Systems - loicz

Prolog
Deltas all over the world are identified to be among the most important sources of ecosystem
goods and services. They are a reflection of past and current global change phenomena along our
coasts as well as the societal dimensions associated with these changes. In terms of spatial and
temporal scales, deltas are an expression of the complex geomorphic interplay between natural
and human forcing, and thus provide a mirror of the multiple feedbacks between man and the
environment. The relevant spatial extension of deltas and the processes that govern their
geomorphologic dynamics and shape encompass the water continuum from source areas in the
river catchments down onto our continental shelves. Along this continuum, anthropogenic
pressures exact their toll, involving changes and responses.
Many transboundary rivers meet the sea in large deltas, thus next to natural processes and flow
regimes deltas may reflect also the upstream sociopolitical condition. Since historical times, deltas
have been society’s edge, supporting social, cultural and economic development and welfare.
Today they are subject to the impacts of climate change and increasingly prone to natural hazards
standing in opposition to accelerating land and coastal use for urbanization, transport business
and exploitation of natural resources. Upstream and in the densely urbanized delta regions,
hydrological management including groundwater abstraction and other human induced soil
compaction have led to the increasingly global phenomena of subsiding deltas and their cities,
exacerbating their vulnerability to storms and erosion. Deltas therefore deserve priority attention
by a truly holistic scientific community. Three institutions in the wider Earth System science
context therefore have joined forces in late 2007 to review our current state of the art
understanding of deltas their physical, biological and socio-ecological features and to identify key
deltaic research questions.
The CSDMS, Community Surface Dynamics Modeling System, Integration Facility based in Boulder,
Colorado, is a virtual home for a diverse community of experts, presently from 22 countries and
135 institutions, who foster and promote the modeling of earth surface processes, with emphasis
on fluids, sediments and solutes in landscapes, seascapes and sedimentary basins. CSDMS
offerings to the public include a library of useful, vetted models, “middleware” to couple models
and data systems, and educational products related to its mission of better understanding our
planet’s surface environment. One of CSDMS’s Working Groups is charged with coordinating
the development of morphodynamic and biogeochemical models that specifically relate to how
deltas respond to both upstream watershed perturbations, and offshore marine climate.
LOICZ, Land Ocean Interactions in the Coastal Zone, is a Core Project of the International Geosphere-Biosphere
Programme, IGBP, and the International Human Dimensions Programme on
Global Environmental Change, IHDP. With a growing network of scientists working on global
scale it has been analyzing coastal change and underlying processes and feedbacks since the early
1990s. During the recent past LOICZ evolved, however, from its originally biogeochemical focus
global into a truly interdisciplinary Earth System Science experiment, which looks into the
multiple features of coastal change in a holistic manner. The key objective is to inform sustainable
development and use of coastal zones by applying a socio ecological systems perspective
along the whole water cascade. It aims to provide the knowledge, understanding and prediction
needed to allow coastal communities to assess, anticipate and respond to the interaction of global
and local pressures which precipitate coastal change. For LOICZ, deltas are one of the top
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