Management of climatic extremes with focus on flood and droughts

The Background Paper Team for the Sub-theme 2 of the WIF2 overviews the background and structure of the issues about management of climatic extremes with special focus on floods and droughts, aiming at facilitating the discussion on this topic as the sub-theme 2 for the Second World Irrigation Forum. With the impeding climate change, intervention to mitigate the impacts of climate change and consequent extreme climate events, especially to reduce the disaster risk, have to be factored in all decision making processes in managing flood and drought, or irrigation and drainage activities. To reduce the disaster risk, the global and local society or community need to assess the weather and climate events with their magnitudes, frequencies, variabilities as well as the forces, the vulnerability of the region and society, and the exposure for the events. The climate change, however, is not easy to project, and its projection are still with uncertainty. Actually, impacts of climate changes on local hydrological regime are being projected with higher reliability, the future events projection and impacts are expected to be more dependable with the development of better projection methods or models and a greater availability of reliable climate data and future scenarios. The impacts on crop phisiology and production are still under initial assessment; and consequent water management system In these current situation, one of the essential and significant attitude is the adaptive approach. The adaptation is the comprehensive and practical measures not only to reduce the disaster risk but also to reinforce the base system with better and deeper assessment of the current system. Since the phenomena or factors associated with climate change and its apparent impacts are difficult to be projected and evaluated at the present phase, the adaptive manner, sometime would be trial-and-error manner, is to be the more effective and feasible measures for managing the extreme flood and drought. It is to be introduced utilizing the best available current knowledge and past experiences, and collecting additional information. At present, using on-going observation and advanced modelling technologies, future events are to be predicted to some extent within certain bounds of accuracy, while in the past natural events, especially the extreme events, were largely unpredictable and we could only react passively to them. Now, with a combination of advanced prediction and local traditional knowledge, there is the potential for wise management of flood and drought, water use in agricultural production, and improvement of regional environments. To keep function of adaptive adaptation in local areas, it is needed to maintain local resource management systems well, including serious flood and drought management systems of the regions or basins. All stakeholders should participate at some level or some extent in the process of monitoring, assessing the baseline and impacts of extreme climatic events, making decisions for adaptation, and establishing mitigation measures. Although the well-designed preparedness is quite general to be proposed, it would be most dependable and reliable action. Research and development for establishing better management systems needs to be promoted, not only against the climate change but also for everlasting improvement of the systems.