关键词: 石羊河流域, 农业生态经济, 三种土地类型组合, 三级区划系统

Abstract: Shiyang river basins, One of the major three inland basin in Hexi desert area, is a typical and independent physical geographic unit. The river comes from the eastern sector of Qilian Mts and flows northward into sand desert, and is about 300 km long and 41149 km² basin areas. The Oasis are developed in the mid-reaches of the corrider plain and lower reaches of the alluvial-lacustrine zone, and the annual precipitation respectively is 100-200 mm and 50-100 mm. The Agro-Ecological environment has clear rule of regional differentiation on midium scale and different suitabilities. Based on the regionalization preciple, the paper heve divided the basin into three ecological-economic regions whose boundary line is about according to upper, mid, lower reaches of the river basim, 9 subregions and 20 minor-regions, the result as follows：
1. Forestry, animal husbandary ecological-economic region in the upper-reaches of river in QiLian Mts including 2 sub-regions and 4 minor-regions.
2. Irrigating agriculture regions in mid-reaches of river in corridor plain including 4 Sub-regions, 9 minor regions.
3. The region conserving economics in the lower reaches of river in Beishan Mts-Alashen Pleateau, including 3subregions, 7 minor-regions.