1.2, geography

(1) The Yangtze River basin has a humid climate and a large runoff. The water of the Nile mainly comes from the tropical grassland climate in the upper reaches, with little precipitation; The climate of the lower reaches is tropical desert, and there is almost no water to replenish the river, and the Nile river has less runoff.

After the completion of Aswan Dam, a large amount of water remained in the reservoir. The climate here is dry and evaporation is strong, and a large amount of water in the reservoir is consumed by evaporation. The amount of water downstream of the reservoir decreases.