Award of Excellence: Sihu Basin Flood Management

CATEGORY: INTERNATIONAL

GOLDER ASSOCIATES

The Sihu basin is situated along the Yangtze, Hanjiang and Dongjinghe Rivers in China. The total area of the basin is over 11,500 square kilometres, and it has a population of more than 4.5 million people.

The basin is subject to potential flooding from nearby rivers, as well as frequent run-off flooding from rain and waterlogging. The flooding can cause large economic damage and social disruption. It can also spread water-borne diseases such as schistosomiasis.

Flood protection and drainage in the basin rely on the operation of a large and complex system, with a total of 37 sluice and control gates (total discharge 5,000 m3/s), two large flood regulating lakes that have a total surface area of over 500 square kilometres, and almost 600 electrical pump stations (total design discharge of 2,700 m3/s and with 230 MW capacity). There is also a complex drainage canal network that is 2,200 kilometres long.

Golder Associates’ Calgary office developed and implemented the Sihu Decision Support System software to help in real-time flood forecasting and to optimize the operations of the flood control and drainage system. The software was developed between 1994-1999 and final field application testing was completed in October 2000. The World Bank has said the project is “path-breaking work in China” and “one of the most successful water resource technical assistance programs” in its China program.

The decision support system was one of three components in the Sihu study, which was funded by the Japanese Consultant Trust Fund from the World Bank. The other two components were done by Golder’s associate, Mikuniya Corporation of Japan, and consisted of the pilot development of a monitoring and communication system, and the pilot development of water users’ associations.

Compatible with local conditions

The Sihu decision support system has three main functions: to help the operators and managers make daily decisions for operating a large number of the water management facilities, to minimize the system’s operating costs, and to prevent flood and waterlogging damage. The software was designed to be compatible with the local decision-making process for operating the flood control and drainage system, and was developed to suit the system’s complex physical characteristics and local conditions.

The system has a large database storing historical and real-time information, and an advanced and accurate model base with a suite of computer models. It has an expert sub-system with an artificial intelligence capability. The model base, which forms the “brain,” includes two modelling systems — one for operational planning, and one for guiding real time operations. The models include hydrologic simulation and forecasting. It also has a friendly user interface.

Golder’s engineers used innovative techniques for the modelling. They applied “fuzzy” grouping techniques to simulate the human behaviours in operating the drainage systems and to optimize the selection of the model parameters. They devised a numerical algorithm for efficiently routing dynamic flow in a complex canal network, and they applied GIS technology. The expert system captures the historical knowledge on the system operations and supplies real-time expert advice.

The application of the computer models since the 1996 flood season has provided accurate hydrologic and system operational forecasts to enable correct decision making and operation of the various drainage facilities. The model helped to avoid the use of the Honghu Lake external flood detention areas. To date, the system has averted flood damages estimated to cost over U.S. $20 million, representing a realized investment return on the system of over 1,100%. The investment return is expected to be higher when the future benefits are taken into account.

The Sihu study involved a large number of Canadian, Japanese and Chinese specialists and effectively overcame the language, cultural and business barriers among these parties. A group of Chinese professionals was trained on the project and they are now responsible for developing similar decision support systems for the flood management of the Hanjiang River system and all the major rivers in the Hubei Province. The successful project sets an example of international cooperation, involving effective and sustainable technology transfer and capacity building for developing countries.

Name of project: Flood Management Optimization for Sihu Basin, China

Other key players: Mikuniya Corporation, Japan; Hubei Water Resources Research Institute, China; Jingzhou Water Resources Research Institute (associates); Dr. Slobodan Simonovic; Wuhan University of Hydraulic and Electrical Engineering