River Basin Decisions Support Systems

By Charles D. D. Howard, P. Eng.

Full text to appear in:
John Wiley & Sons
New York
Water Encyclopedia
April 2005

The interacting components of water resource systems incorporate physical, biological, chemical, and institutional constraints and objectives (Figure 1). Water projects are difficult to manage efficiently within potentially conflicting objectives and constraints on water quality, river flows, and lake levels. There are many types of decisions and these must be made on a timely and reliable basis. Decisions vary from time scales of minutes for assigning loads to hydroelectric generating units to weeks and months for managing water quality, reservoir levels, and pumping from groundwater. At shorter time scales decisions are based on deterministic analyses. At longer time scales decisions are dominated by consideration for probabilities.