Global Change and its Impact on Water Resources: the Role of UNESCO’s International Hydrological Programme - Weller and Liska page 2

This may cause deterioration in the quality of freshwater bodies, putting further strain on the already fragile balance between supply and demand in many countries. Even where precipitation might increase, there is no guarantee that it would occur at the time of year when it would be useful. There is also a likelihood of a change in flood and drought frequency and severity.


HELP – Hydrology for Environment, Life and Policy


HELP is a cross-cutting and transdisciplinary research Programme that is creating a new approach to integrated catchment management through the creation of a framework for water law and policy experts, water resource managers and water scientists to work together on water-related problems. An important research question within HELP basins is how knowledge, understanding, and predictive modelling of the influence of global climate variability and change on hydrological variables and remotely sensed data can be used to improve the management and design of water resource, agro-hydrological and eco-hydrological systems.
Subsidiary issues within this topic include:

  • How significant is the relationship between the statistics of hydrological variables and observable global phenomena, and how does this change with location?
  • How can remote data capture, and advanced information transfer technologies best be applied to improve the management and design of water systems?
  • How can predictions of seasonal to inter-annual variations be used to improve the management of water, including for disaster prevention (floods and droughts)?
  • How significant are multi-decadal fluctuations in climate, and how can knowledge of such fluctuations be used to improve the design of water systems?
  • What is the hydrological significance of potential anthropogenic climate change, and how can predictions of such change best be used to improve the design of water systems?

FRIEND: Flow Regimes from International Experimental and Network Data

FRIEND is an international research Programme that helps to set up regional networks for analyzing hydrological data through the exchange of data, knowledge and techniques at the regional level. Through its eight regional groups, the Programme focuses on the assessment of the impact of global change drivers on flow regimes but especially on areas which are likely to experience change in the near future – through temperature, seasonal differences, and transition zones. It developed several flood-related tools such as early flood forecasting systems and methods for design floods.
FRIEND’s main scientific research focuses on the understanding of the complex nature of hydrological variability in space and time in different hydro-climatic and hydro-geological environments (temperate climates, extreme elevation, monsoonal regimes, snow and ice regimes, hard rock and unconsolidated river basins), data-sparse regions. The Programme deals with environmental changes (climate change; land-use change) and their impacts in particular in the area of water-related disasters such as floods and droughts to understand the underlying processes of major recent events and addressing scaling issues.
Regional FRIEND groups focus on research themes such as low flows and hydrological droughts and their climatic drivers, as well as on the anthropogenic influence on droughts and low flows. Research results demonstrate the difficulty of distinguishing between natural variability and human influences that reduce or enhance low flows and drought. Without detailed information, it is therefore impossible to attribute changes in drought characteristics to certain causes. For example, in many regions the impacts of land use change, urbanization or abstraction for irrigation override the effect of climate change. A promising approach is an integrated observation-driven approach that confirms the dependencies with modelling.
The European branch of the FRIEND research programme is researching the impact of climate change on droughts through the “Global Change and Ecosystems” project, as part of the EC-funded project WATCH (Water and Global Change). A study on trends in observed low flow and stream flow drought has been conducted and indicates the difficulty in detecting the climate signal in the hydrological time series. The research shows that the frequency and severity of droughts in Europe is a multifaceted problem and depend not only on the changing climate conditions or is a result of climate variability but depends also on the hydro-geological conditions (storage capacity) of the basins, the time period selected and the selection of the drought index itself.