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四川盆地四面环山,盆壁山区海拔1000-2000米。盆内地势北高南低,中间丘陵起伏,海拔在300-700米之间,相对高度不超过100米。属亚热带季风气候,盆地南北热量条件有显著的不同,东西水份条件有很大的差异。盆地冬季温和夏季炎热,气温以长江河谷最高,边缘山区最低,其他地区介于二者之间,由南到北逐步降低。各地常年降水量大部份在1000-1200毫米之间,雅安至乐山一带最多,沱江、嘉陵江上游及川东长江河谷区最少,可划分为东部春季多雨伏旱常现区,与西部春季少雨春旱常现区。
Sichuan Basin surrounded by mountains, basin mountains 1000-2000 meters above sea level. The terrain north of the basin is high in the south and low in the middle with undulating hilly areas at an elevation of 300-700 meters and a relative height of no more than 100 meters. Is a subtropical monsoon climate, the basin north and south heat conditions are significantly different, east-west moisture conditions are very different. The basin is warm in winter and mild in summer, with the highest temperature in the Yangtze River valley and the lowest in the edge mountains. The rest of the basin is between the two and gradually decreases from south to north. Most of the annual precipitation around the 1000-1200 mm, the largest area of Ya’an to Leshan, the upper reaches of Tuojiang, Jialing River and the eastern part of the Yangtze River valley, can be divided into the eastern spring rainy and dry areas, and the western spring less rain and drought Now area.