The TA was successfully completed. The final report was submitted to ADB in February 2010. Study findings are summarized below.
1. National Flood Management Strategy
To shift from dependence on structural flood control measures to a balanced approach using both structural and nonstructural measures, the Ministry of Water Resouces supported by the previous TA4327-PRC: Flood Management Strategy Study prepared a national flood management strategy (NFMS) in 2005. A key aspect of the NFMS is a flood risk management which is defined as the treatment of hazard, exposure, and vulnerability. In general, flood hazard is managed by structural measures such as flood control works. A variety of nonstructural measures such as land use management and flood forecasting and warning are appropriate for managing exposure to flood hazard and the vulnerability of people and assets that remain exposed.
2. Review of Provincial Flood Management
Flood management strategies in Hunan and Jiangxi provinces were reviewed with an account of laws and regulations, the physical situation and flood hydrology, and the strategic approaches featuring both structural and non-structural measures. Key issues for future flood management were also analyzed. Results of the review and analysis were reflected in the development of provincial flood management action plans.
3. Development of Provincial Flood Management Action Plans
Provincial flood management action plans were developed for the two provinces to implement the NFMS. Key actions are summarized as: (i) a meeting of heads of relevant provincial departments to plan joint actions; (ii) securing stable sources of funding; (iii) improving flood risk mapping; (iv) raising community awareness of flood risk and public preparedness; (v) training activities; (vi) introducing and applying structured methodology for systematic planning and project appraisals; (vii) improving and extending data management and decision support systems; and (viii) improving and extending flood forecasting and warning systems, including flash flood warning systems.
4. Pilot Trials
In Hunan Province, the Linan flood detention area (FDA) in Li county was selected for pilot trials. Linan FDA is for temporary detention of floodwater. Resettlement of the population took place and a there is gated diversion structure in the surrounding dikes. Pilot trial activities include (i) review and analysis of diversion operations to Linan FDA, (ii) review of flood warning and emergency response arrangements for Linan FDA, and (iii) identification of issues related to compensation for use of Linan FDA. While the gated diversion structure enables Linan FDA to effectively mitigate floods, little guidance on gate operations is provided; therefore preliminary operating rules were devised. It was found that some people using land in Linan FDA do not have appropriate awareness that the FDA will be required occasionally for temporary storage of floodwater. Even though it is only six years since Linan FDA was last used, complacency has already emerged in some land users. An organized and sustained campaign to raise awareness of the flood risk and maintain public preparedness is recommended to address this problem. Improved flood risk mapping is recommended as an aid to emergency response planning and action for Linan FDA.
In Jiangxi province, Lichuan county located in mountainous terrain subject to flash flooding was selected for pilot trials. Two pilot trial activities were initiated: (i) flood risk mapping for a remote valley; and (ii) application of flood risk management to the flash flood area. Although past flood data were limited, maps were prepared using GIS showing the extent and depths of the 1998 flood. The maps provide a basis for preliminary flood hazard zoning. However collection of more flood data and its integration into GIS would allow refinement of hazard zoning and improvement in accuracy of inundation extents and flood depths. Guidelines for flash flood risk management were prepared considering overseas developments in flash flood management. An outstanding need for sustained funding for ongoing maintenance of flash flood monitoring and warning systems is noted.
The Consultant undertook the pilot trial activities with support from local and provincial governments, and the findings of the pilot trials were presented to and discussed with local and provincial government officials at information and feedback sessions conducted in both provinces during October 2009.
5. Proposed Prototype Investment Projects
Several prototype projects for potential future investment are proposed for the two provinces. In summary, these include hydraulic modeling for more accurate simulation of diversion operations, development of improved flood forecasting, improved flood risk mapping and flood hazard zoning, development of a computerized flood management asset database, and preparation of a flash flood risk management plan. These proposals are consistent with the objectives of the NFMS and the flood risk management, and are compatible with the provincial flood management action plans.
6. Knowledge Product
A knowledge product (KP) on flood management strategy in the RPC is being prepared based on lessons learned from the TA and previous TA4327 and will be published within 2011.