TY - Acta Geographica Sinica A1 - LIU Jiyuan, XU Xinliang, SHAO Quanqin T1 - The Spatial and Temporal Characteristics of Grassland Degradation in the Three- River Headwaters Region in Qinghai Province Y1 - 2008-04-25 00:00:00.0 JF - Acta Geographica Sinica JO - Acta Geographica Sinica SP - 364 EP - 376 VL - 63 IS - 4 UR - {https://www.geog.com.cn/EN/10.11821/xb200804001} N1 - 10.11821/xb200804001 ER -