Previous PageTable Of ContentsNext Page

Seasonal streamflow forecasts to improve management of water resources

Clarkson, N.M. Mr; Ph: (07) 4688 1248; Fax: (07) 4688 1477; clarksn@dpi.qld.gov.au

Graham, L.B. Mr; Ph: (07) 4688 1059; Fax: (07) 4688 1188; Lamond.Graham@dnr.qld.gov.au

McMahon, T.A. Prof; Ph: (03) 9344 6641; Fax: (03) 9344 6215; tam@engineering.unimelb.edu.au

James, R.A. Mr; Ph: (03) 9669 4605; Fax: (03) 9669 4725; r.james@bom.gov.au

Research organisations: Queensland Department of Primary Industries, PO Box 102, Toowoomba Qld 4350; Queensland Department of Natural Resources, PO Box 318, Toowoomba Qld 4350; Department of Civil and Environmental Engineering, University of Melbourne, Parkville Vic 3052; Hydrology Unit, Bureau of Meteorology, GPO Box 1289K, Melbourne Vic 3001

Sponsors: LWRRDC, Land and Water Resources Research and Development Corporation

Objectives: To catalyse improvement to rural, agricultural, environmental and urban water management in Australia by:

1. Developing methods to forecast streamflows and runoff that are based on streamflow persistence and the latest developments in seasonal climate forecasting by June 1998;

2. Assembling a national streamflow and runoff data set from 500 locations throughout Australia for use in the AUSTRALIAN RAINMAN software package by June 1998;

3. Working with water managers (mainly primary producers and water authorities) in four representative regions of Australia to assess the value of streamflow/runoff forecasts in water management by June 1999;

4. Building a communications program that will facilitate adoption of improved practices during the project and importantly, beyond the end of this project, by June 1999.

Methodology: Carry out pilot studies with primary producers to identify needs and assess benefits to farmers. Assess value of forecasts in water resource management systems in collaboration with water agencies. Assemble a national collection of observed and simulated streamflow data from water authorities in Australia (the national coordinating structure of ARMCANZ will be asked to facilitate this process). Adapt forecast methods and streamflow/runoff data for use in AUSTRALIAN RAINMAN Version 4. Develop a communications program to ensure adoption. Manage the project to ensure effective coordination, collaboration, evaluation and reporting.

Progress:

Task 1. Pilot studies with primary producers.

Pilot studies to determine the value of seasonal forecasting are continuing with four groups in the Condamine (Qld), Lachlan (NSW), Collie/Preston/Harvey (WA), and Pioneer (Qld) catchments. This has involved a case study workshop, setting up 5 individual cases in each catchment, preparing suitable streamflow or related data, and contact visits. The case studies are investigating forecasting, value of software and its user-friendliness, and in some cases economics.

Task 2. Assess value of using forecasts in water resource management systems in collaboration with water agencies.

Research into assessment of forecasting methods has been completed. The first method is based on a linear discriminant analyses of the historical streamflow and ENSO data, and the second method uses a weighted least squares regression approach. The second is a conceptually better method, but its use is limited to streamflow-ENSO relationship that yields normally distributed residuals. For the RAINMAN package, estimates of the probability of exceedances of streamflow amounts can be forecast by considering the historical streamflow data in pre-determined range of ENSO values.

The value of forecasting for management of water resources is currently being assessed in two water resources systems. The first is an urban system in Benalla (Victoria), where the objective is to assess the benefits and risks (measured in terms of the water sales and the need to apply restrictions) of using the seasonal streamflow forecasts for making decisions on water restrictions. The second study is of the rural system in the Lachlan River Basin (New South Wales), in conjunction with another research project. Various scenario studies will be carried out to assess the benefits and risks of using the streamflow forecasts for making decisions on water allocation and on the types and amounts of crops to be planted.

Task 3. Assemble a national collection of streamflow data.

Streamflow data for a total of 240 stations have been received from QLD, NSW, VIC, TAS, SA and WA and are in the process of being stored in HYDSYS for further checking and processing ready for use in RAINMAN. Some additional stations from Victoria and NT have still to arrive. Discussions are also under way with Water and Rivers Commission, WA to determine whether additional work can be carried out to fill in some of the gaps in the WA stations. It is anticipated that between 280 and 290 stations will be included in the data set.

Task 4. Adapt forecast methods and streamflow / runoff data to Australian Rainman.

The data (both daily and monthly) will be converted to RAINMAN format. The determination of the final tools for forecasting streamflow requires further work before incorporation into the RAINMAN format. Research in Task 2 has indicated that the best tool varies in different parts of Australia. It could be the SOI, streamflow persistence or the Bureau's new system based on sea surface temperatures (SSTs), depending on location.

Meanwhile preparation of RAINMAN as the carrier of streamflow information is progressing well. A beta copy of the new Version 3 for Windows is nearing completion, and the official launch was in February 1999. Streamflow information will be incorporated into a revised version later next year.

Due to a shortage of suitable data for Task 1 case-study volunteers, streamflow records for some sites were patched and extended by simple proportion based on a nearby long-term station.

Task 5. Communications program to ensure adoption.

Key components are to develop and implement a communications plan, create national awareness of the project, develop a property management planning workshop for primary producers, develop a workshop programme, publish project results, and link the resource materials and activities to on-going communications programs. The majority of the work started following the appointment of an officer in October 1998.

Task 6 Coordination, collaboration and evaluation.

Milestone Reports were delivered in July 1997 and August 1998, a special report on the seasonal forecasting research in Task 2 was prepared, and a Communications Plan was developed. The team met twice during the year and the Steering Committee once. Some adjustments were made to timing of milestones, and the project has been extended by three months to March 2000.

Keywords: Stream flow; runoff; forecasting; seasonal variation; water resources; water management; databases

Period: starting date 1997-02; completion date 2000-03

Status: Ongoing

Publications:

Clarkson N.M., Clewett, J.F., Owens D.T. and Abrecht, D.G. (1997). Will it rain? Managing El Niņo risks with the AUSTRALIAN RAINMAN computer package. Proceedings of the XVIII International Grassland Congress '97, Canada.

Chiew, F.H S., McMahon, T.A., and Zhou, S. (1997). Streamflow variability, seasonal forecasting and water resources systems. Symposium on Applications of Seasonal Forecasting in Agricultural and Natural Ecosystems - The Australian Experience, Brisbane, 10-13 November 1997.

 

Previous PageTop Of PageNext Page