Catchment description

The Ca River basin is a transboundary river basin shared between Laos and Vietnam.

Key characteristics

  • Area - 31,000 km2
  • Population 3.4 million (2005)
  • The river runs northwest – southeast through the three Vietnamese provinces of Thanh Hoa, Nghe An and Ha Tinh before flowing out into the ocean.
  • Land cover - Forests 60%, Agriculture 21%
  • Average annual precipitation 1570 mm, Upstream rainy season May to October, downstream August to November
  • Average annual temperature 26.5 ℃
  • The floods during monsoon season contributes 55-75% of the annual flow (Link)

Existing water use - Farmers commonly plant rice in a double cropping pattern during a year. Three water reservoirs (Ban Ve, Khe Bo and Hu Voc Mau) have already been built to supply water for agriculture, urban areas flood control and hydropower generation. For the baseline period of 15 years (2001-2015), the average agricultural yield was 2929 kg/ha. Also, the average urban water demand coverage (supply) was about 97% and 717 gigawatt-hour hydropower energy was generated.

Key Water management problem - Irrigation demand is not always completely met and irrigation deficits lead to crop yield reductions.


You task is to make robust decisions for the next 30 years that are effective for different sectoral demands: agriculture, industry, urban and environment in the basin. In this game, the Huai Sai Bat (HSB) River Basin as a case, you will assess how robust strategy of water resources management associated with two uncertain future environments: climate change and land-use change.

Considering those uncertainties, you know that there will have the potential to subsequently generate future water shortages in the HSB. Thus, four possible water management strategies are formulated to alleviate the risks of the water scarcity in the basin while taking the uncertainties into account in the decision-making process. What are the most robust strategy of water resources management to improve the conditions about water security in your basin?

The current situation, so called "Baseline" has a score of 0. If you get a score:

  • greater than 0 indicates that you have done better than the past;
  • equal to 0 indicates that you have performed neither better nor worse than the past;
  • lower than 0 indicates that you have done worse than the past.

Uncertainty and Basin development choice

Water resources strategy