Global Change and its Impact on Water Resources: the Role of UNESCO’s International Hydrological Programme - Referencies

ISI – International Sediment Initiative

The International Sediment Initiative advances sustainable sediment management at the global scale since it can have major economic and environmental effects on water resources management. Sedimentation not only reduces reservoir capacity due to the interception of river solid transport but also increases flooding risk produced by the bed aggradations of piedmont rivers. There is a potential collapse of structures along rivers subject to degradation and erosion of beaches near the mouth of rivers with sediment depletion which is observed in many parts of the world. The programme looks into many different aspects such as the development of a sediment information system, a global evaluation of sediment transport (GEST project), collects case studies of sediment problems and sediment management for large river basins in different environments, reviews erosion and sedimentation research (Di Silvio and Basson, 2008), and fosters an initiative to promote education and capacity building in the sediment field.

The theme of global change and its impact on erosion and sediment dynamics is central to all of these aspects since it is now clear that change is a key feature of those dynamics and such change is in turn a key driver of sediment-related problems and has a fundamental influence on sustainable river basin management. ISI plays an important role in highlighting the wider context of global change and the importance of such changes to erosion. The Impact of Global Change on Erosion and Sediment Transport by Rivers: Current Progress and Future Challenges» has been published in the scientific paper series of the WWDR 3 (Walling, 2009).

Eco-Hydrology program

The impact of climate change on biodiversity under specific socio-political constraints is elaborated within IHP’s Eco-Hydrology program. The programme is concentrating on the level of environmental protection to be provided under climate change impacts. Developing countries will usually be least able or willing to consider the issue of the water required for environmental protection; their first priority is usually to take care of the immediate, basic needs of their population. The Eco-Hydrology initiative aims to raise awareness of these issues so that these two objectives are not contradictory and there are pathways to strike a balance under enhanced climate variability and climate change scenarios. The Eco-Hydrology cross-cutting agenda includes the following issues:
  • The role the environment plays in securing water resources under different climate regimes;
  • Determining a value on the “natural” environment;
  • Identifying the impacts of environmental change on water resources.

Urban water management program

The urban water management programme of the International Hydrological Programme generates approaches, tools and guidelines which will allow cities to improve their knowledge, as well as analysis of the urban water situation to draw up more effective urban water management strategies. The programme carries out the following activities:

  • Developing solutions for more sustainable storm water collecting practices, taking into account intense rainfall events, increasing urban population size and ongoing detrimental changes on water resources from urban storm water;
  • Minimizing urban storm water flow impact on water masses. This requires defining technical elements and managing rules to shift from the traditional engineering “optimization” goal to a more holistic “system resilience” goal;
  • Consideration of both assets management in existing urban places and new based technological solutions in developing sub-urban areas;
  • Ensuring that only minimal amounts of polluted waters reach the natural system even during more intense rainfall events. This is applicable both to combined and separated sewer systems.


GRAPHIC – Groundwater assessment under the pressure of humanity and climate change

IHP’s GRAPHIC programme is working on the impact of climate change on groundwater systems. The programmes activities include:

  • Assessment of the impacts of global change (e.g. climate change and human pressures) on groundwater resources and support Member States in addressing regional needs through global coordination;
  • Improvement of the understanding of how groundwater contributes to the global water cycle and evaluates the changes to groundwater storage and fluxes;
  • Better defining growing population pressure on groundwater resources, global warming impacts on groundwater recharge rates, rising sea levels and saltwater intrusion;
  • Raising awareness of decision makers, implementers, users and the general public of the importance of groundwater as a store of freshwater to encourage improved protection and sustainable use;
  • Facilitating the county/regional groundwater assessment and exchange of information via seminars, workshops and conferences.