SIXTH IWRA WORLD CONGRESS ON WATER RESOURCES

ABSTRACT

This study utilizes chance-constrained programming (CCP) to determine the optimal service area for Huai Aeng Reservoir in NE Thailand. CCP allows for an explicit incorporation of erratic monsoon rainfall amounts in design considerations. In contrast to the present situation, which was designed based on average flows, where both the wet and dry season service areas are 3,371 ha with a low rate of utilization for the dry season area, using CCP the optimal design (taking into account rainfall and resulting inflow variability) is an irrigated area of 2,192 ha using extensive canals for wet season rice and 1,179 ha using intensive canals and farm ditches for dry season field crops as well as wet season rice. Excluding farm labor costs, the new design has a B/C ratio of 1.77:1 compared to a B/C ratio of 1.03:1 for the present design.