Water problems pose growing threat to coastal areas

8 October 2002 Low-lying coastal areas highly vulnerable to natural hazards and the effects of climate change. They are also home to more than 60 % of the world population, despite the fact that coastal areas and small islands cover less than 20% of the earth’s surface – and the coastal population is growing..

In addition to being among the most densely populated regions on Earth, coastal areas and small islands are also subject to extraordinarily intensive industrial and commercial use, agriculture, aquaculture and tourism. They yield 90% of the global fisheries and about 25% of global biological productivity. Serious problems are arising as these dual pressures on the environment grow: conflicts between different uses of coastal land and waters, overexploitation of coastal resources, discharge of wastes and effluents into coastal waters – as much as 70% of the world’s cities are situated on the world’s coasts –, elevated risk of storm damage, increasing stress by sea level change and coastal population growth.

Different approaches to solving these problems were discussed at an international symposium organized on 9–12 September in Bremerhaven (Germany) by UNESCO’s International Hydrological Programme (IHP), in cooperation with the national committees of Germany and the Netherlands.

In addition to discussing tools for sustainable water management in coastal areas, the symposium studied ways of increasing public and political awareness of the vulnerability of coastal zones. One solution would be for coastal planning to be integrated more strongly into existing frameworks to ensure that humans were able to adapt to their changing environment. The concept of social vulnerability also needed to be incorporated into integrated coastal zone management.

The need for interdisciplinary research involving both the natural and the social sciences to address the human dimension of global environmental change and to improve understanding of sustainability as conditioned by natural systems was highlighted by the World Conference on Science. The Conference considered the freshwater issue and the hydrological cycle, climate variations and change, oceans and coasts to be areas requiring special attention.

Participants in the symposium regretted the lack of easily available and easily accessible data on the hydrological cycle in low-lying coastal areas. They called for multinational, multidisciplinary, multispatial and multitemporal research work to solve complex coastal problems using expertise, equipment, data and methodologies from various nations.

The need for this approach was underscored by the somewhat absurd situation today whereby two inseparable processes in nature – namely those that drive both salt water in and freshwater out under the shoreline – are being investigated by separate groups using different methodologies. (These processes are expressed on the sea floor as ‘submarine groundwater discharge’.) Participants recommended that submarine groundwater discharge be consistently and explicitly integrated into coastal water budgets.

Participants proposed launching a project on submarine groundwater discharge to investigate the pathways for freshwater and nutrients to the coastal zone in an integrated fashion. This can best be done by developing ‘flagship’ sites for extrapolation to larger areas. These sites would be characterized by joint studies using hydrological modelling, geophysics, geochemical tracers and other approaches.

Another submarine groundwater recharge project could investigate the process, potential and possibilities for sustainable use of the coastal areas of the world. Studies could make use of remote and in situ data and the results could be published as a handbook of detailed investigations and later as an atlas.

Participants came from 20 countries. They represented the global change science community and organisations like UNESCO, the World Meteorological Organization (WMO) and UN-ESCWA.

For further information, contact l.mandalia@unesco.org