一、内陆河概况1.地理位置　我国的内流区域和外流区域的界线北线大体上沿大兴安岭—阴山—贺兰山—祁连山 (东端 )一线 ,南端比较接近于 2 0 0毫米的年等降水量线 ,内陆河分布在这一线的西北部地区 ,具体为西起帕米尔高原国境线 ,东至大兴安岭 ,地处东经 73°35′～ 199°55′ I. Overview of inland rivers 1. Geographic location The north line of the boundary between outflow and outflow areas of our country is roughly along the Daxinganling-Yinshan-Helan-Qilian (east) line and the southern end is closer to the annual precipitation of 200 mm The amount of the inland river is located in the northwestern part of this line, specifically west of the Pamir plateau border and east of the Greater Khingan Range, which is located between 73 ° 35 ’~ 199 ° 55’