Abstract:
An overview of the four decades of the development of the science of hydrology, spearheaded by the International Hydrological Programme (IHP), suggests that new insights into 'water dependencies' in ecosystems, are required in future hydrological endeavours. Given the progress of the multiple UN supported action, and the worldwide work towards the successful achievement of the Millennium Development Goals, the international community has committed itself to responding to the recognised risks to ecosystems from poor management of water. In the forthcoming decade the science of hydrology now needs to deepen its focus on inter disciplinarities, so that policy makers operate within an informed atmosphere with access to the essential notions, at a time of significant global changes such as the increasing global climatic variability and the relentless acceleration in globalisation of economies.
In considering the 'whither to' in the title of this paper, the start point is that water is at the centre of interactions between many of the Earth's systems. The science of hydrology has been able to corroborate the findings of related sciences that many of the planet's systems (hydrological as well as ecological) are strongly interdependent, and that a number of these systems are now under identifiable stress from population growth, urbanization, land conversion or the accumulation of many different pollutants. Global programmes such as World Water Assessment Programme, GIWA and the Millennium Assessment have made the same findings. Stress levels in some regions are so elevated that the global community is now prepared to respond to the concerns put forward by hydrologists over the past four decades.
