Page - 216 - in Book of Full Papers - Symposium Hydro Engineering

storage is in the interdecadal cycle of change,showed that the effect of the impoundment of the Three Gorges Dam on the surrounding of precipitation is not obvious. 4. NUMERICAL SIMULATION OF THE CLIMATE EFFECT OF THE THREE GORGES RESERVOIR Regional climate modeling shows that the Reservoir would produce some impact on the neighboring areas climate, But the maximum range of impact is not more than 20km,The Reservoir would noticeably bring down the air temperature above the water surface, by 1℃ in the winter, and 1.5℃ in the summer,with only 0.1°C for the land surface close to the water. The water body’s evaporative cooling effect would cause the air to sink, and as a result there would be less precipitation. However, the decline in precipitation would be small in winter, a 1 to 2 per cent drop within a 10km radius, and higher in summer, a 10 per cent drop. That 10 per cent would weaken to 3 per cent at a 10km radius and to 1 per cent at a 20 km radius.The numerical model simulation results show that the Three Gorges reservoir, as a typical and very narrow channel reservoir, has a very small impact on the regional climate. a 216