论文部分内容阅读
四川三江流域(嘉陵江、涪江、沱江)及岷江上游位于长江上游,地处四川盆地向青藏高原、云贵高原和秦巴山脉的过渡地带,北缘和东北缘为米仓山和大巴山,海拔1000—2200m。东缘、东南缘及南缘为巫山、七曜山和大娄山,海拔多为800—1800m。西缘为邛崃山,龙门山和大凉山东坡,地势较高,海拔多在1200m以上。该流域人口密集,土地肥沃,水热条件较好,是四川省主要农业产区,农业经济在全省占有重要的地位。但是,由于三江流域及岷江上游的气候、
The Three Rivers (Jialing River, Fujiang River, Tuojiang River) and the upper reaches of the Minjiang River are located in the upper reaches of the Yangtze River. They are located in the transitional zone from the Sichuan Basin to the Qinghai-Tibet Plateau, the Yunnan-Guizhou Plateau and the Qinba Mountains. The northern and northeastern margins are Micangshan and Dabashan, 1000-2200m. The eastern, southeastern and southern margins are Wushan, Qiyao Mountain and Dalaoshan, with an elevation of 800-1800m above sea level. The western margin of Qionglai Mountain, Longmenshan and Daliangshan east slope, higher terrain, more than 1200m above sea level. The densely populated basin, fertile land and good hydrothermal conditions are the major agricultural producing areas in Sichuan Province. The agricultural economy occupies an important position in the province. However, due to the climate in the upper reaches of the Three Rivers and the Minjiang River,