Improving main system water management in China: A demonstration project in the Zhanghe Irrigation Scheme

LWR/2001/001: Improving main system water management in China: A demonstration project in the Zhanghe Irrigation Scheme

China

University of Melbourne, Australia

Associate Professor Hector Malano
Phone: 03 8344 6645
Fax: 03 8344 6868
Email: h.Malano@civenv.unimelb.edu.au

• Wuhan University, China

$161,026

01/07/2002 - 30/06/2004

01/07/2004 - 31/10/2004

Dr John Skerritt

Irrigation plays a pivotal role in China's plans to meet future food demand. But the volume of water available for irrigation is under threat, largely from the increasing thirst of the country's urban and industrial sectors. In the Zhanghe river basin in China's Hubei province there is strong interest in widespread introduction of water-saving irrigation (WSI) techniques, which can increase food production using less water. But effective introduction of WSI depends on adequate operation of the water supply system.
Similar problems in Vietnam led Australian scientists from Melbourne University, under the leadership of Professor Hector Malano, to participate in an ACIAR project to study system-wide water management in that country's irrigation schemes. They worked with Vietnamese agencies to adapt a computer model, IMSOP (Irrigation Main System Operation), to analyse and improve operations and develop the infrastructure and institutional arrangements for pricing irrigation supply services. The team also modified and adapted the computer model ASSET MANAGER to speed up collection, retrieval and analysis of asset data.
The project's success caught the attention of the Zhanghe irrigation authorities, who approached the Australians on the team to see if they could undertake a similar study in China. Together they developed this small ACIAR project, designed to improve main system water management in China through a demonstration study in the Zhanghe Irrigation Scheme (ZIS).

The project's main objective was to appraise the situation in Zhanghe and modify the IMSOP and ASSET MANAGER models to include features peculiar to Chinese irrigation schemes.

The focus of the study centred on Zhanghe's Fourth Main Canal that operates under an arranged demand schedule, whereby farmers request water deliveries from the agency as they need them. This canal receives water from the main river system on average four times a year, for 5-15 days each time. Farmers must give three days notice of their need for water to their canal station, which aggregates the farmers' orders. The Main Canal Office then aggregates all canal station demands to determine the total canal inflow required.
Researchers developed and implemented improved operational rules for the East Branch canal of the ZIS, to better support the adoption of WSI at the farm level. This work was designed as a demonstration project for the subsequent upscaling to the entire ZIS and adoption by other irrigation schemes China.
They also developed a program for long-term management of the hydraulic infrastructure to ensure that future modernisation and rehabilitation programs would incorporate the operation and adoption of WSI and provide irrigation services in the most cost-effective manner. Finally they focused on the dissemination of the improved operational framework to other irrigation schemes in China.

The project team found that farmers tended to delay their water orders on the expectation that rain would reduce their water bill (which is charged on a volumetric basis). This led to a congestion of orders when farmers all realised their crops were in danger of water stress and therefore submitted their requests within a short period of time. At that point the system was unable to deliver sufficient water for all.
The team modified and adapted the IMSOP model to account for this mode of operation, resulting in the addition of a utility for prediction and sequencing farmer's orders. Other IMSOP modifications came from data collected and processed from the Tuanlin weather station's databases. Through quality checks the team identified and corrected many inconsistencies.
It emerged that changes in the water pricing policy in recent years had led to reduced water demand from farmers and a shortfall in revenues from water fees in relation to cost of water supply. The ASSET MANAGER analysis allowed the irrigation company to calculate actual operational cost of the Fourth Main Canal and develop a sustainable water fee policy.
Wuhan University scientists translated the modified versions of IMSOP and ASSET MANAGER into Chinese and they are now installed on ZIS's computers. China's National Centre for Irrigation and Drainage intends to promote the work at ZIS to other irrigation areas in China. Such guidelines will be vital as the Chinese Government tackles the massive effort to rehabilitate and modernise ailing structures.
By facilitating more widespread adoption of WSI practices the project will also help to address problems of increasing water shortage and competition that are prevalent in vast areas of China, especially north of the Yangtze River. In several regions, the lack of water may limit future economic development.