The Potential of Earth Observation for the Analysis of River Deltas and the Coastal Zone

Kurzfassung

The face of our planet is changing at unprecedented speed. Total population grew by 26% between 1992 and 2010, the number of megacities with over 10 million inhabitants more than doubled between 1990 and 2010, and the the latest, uncontestable climate trends, sea level rise, and sporadic endogenous and exogenous natural hazards aggravate environmental change, as does the constant demand to cope with and adapt to ever changing livelihoods. The major settled river delta areas of our planet are highly dynamic social-ecological systems, which are especially exposed to the impacts of socio-economic development, urbanization, changes in climate, and natural hazards. Although river deltas only contribute 5% to the overall land surface, nearly six hundred million people live in these environments, which combine a variety of appealing locational advantages such as flat topography, fertile alluvial soils, access to sea and freshwater resources, transport hub functions, a rich biodiversity of marine, brackish and inland ecosystems, as well as - often - abundant underground resources of hydrocarbons (oil, gas), and salts At the same time, these highly dynamic, valuable environments are exposed to a variety of threats. Urban areas, industry, infrastructure, agriculture, and aquaculture all extend into formerly untouched land and disturb and/or replace valuable ecosystems such as wetlands, coastal forests, and marshes. Increasing water, soil, and air pollution accompany this process. Sediment compaction through heavy structures and underground resource extraction adds to a natural subsidence component. The same applies for many coastal areas globally. At present an unrivalled amount of remotely sensed earth observation data is globally available in satellite data archives. Imagery from coarse-, medium-, high-, and highest-resolution optical, multispectral, radar, and thermal infrared sensors is waiting to be exploited to reveal its full potential. The USA and Europe have set the pace in sharing earth observation resources. Along with this current trend of opening up numerous satellite data archives worldwide go increasing capabilities to handle and explore big data. Compared to former uni- or bi-temporal mapping endeavours, the current benchmark is the exploitation of remote sensing time series to reveal land surface dynamics at differing spatial-, and temporally-dense scales. The goal of this contribution / talk is to demonstrate this profound potential for large river deltas and coastal areas globally.