干旱区研究
Drought Trend over the Grasslands in the Tianshan Mountains, Xinjiang in Recent 55 Years Based on SPEI
GUO Yan-yun, HU Qi, FU Wei-dong, WANG Sen, LIU Yan
Arid Zone Research . 2019, (3): 670 -676 .  DOI: 10.13866/j.azr.2019.03.18