ABSTRACT: The goal of this study is to develop different scenarios of water resource availability in Panama under climate change-induced temperature and precipitation variability, considering a potential doubling of the atmospheric CO₂ concentration in the next 100 yr. The water balance model CLIRUN3 was combined with 20 yr of basic climate information records (precipitation, potential evapotranspiration and water flow) to simulate monthly river runoff in the Chagres (Panama Canal) river basin. This basin supplies water to 25% of the country's population and is of great importance for international navigation. In the cases of the Chiriquí and La Villa river basins, 10 yr of records were used. The Chiriquí river basin is the main national source of hydropower, while the La Villa river basin is of agricultural importance. The Chagres river basin is part of the Atlantic watershed while the others belong to the Pacific watershed. The model was calibrated and run for both watersheds under scenarios with temperature increments of +1 and +2°C, while the precipitation changes considered were ±15% for the Pacific and ±20% for the Atlantic watershed. It was observed that the monthly runoff tends to decrease by 3 to 42% of the mean value in both watersheds when temperature increases and precipitation decreases. If both temperature and precipitation increase, the mean runoff value in the Pacific basins will be reduced by 5 to 35% from November to April and increased by 4 to 40% in the remaining months. In the basin of the Atlantic watershed all simulated monthly values are 3 to 50% higher than the actual mean.

KEY WORDS: Panama · Water resources · Climate change

Published in CR Vol. 9, No. 1-2 (1997) on December 29
ISSN: 0936-577X. Copyright © Inter-Research, Oldendorf/Luhe, 1997