1. Belayneh, A., J. Adamowski, B. Khalil, et al., 2014: Long-term SPI drought forecasting in the Awash River Basin in Ethiopia using wavelet neural network and wavelet support vector regression models. J. Hydrol, 508, 418–429, doi: 101016/j.jhydrol.2013.10.052.
2. Blaikie, P., T. Cannon, I. Davis, et al, 1994: At Risk: Natural Hazards, People’s Vulnerability, and Disasters. Routledge Publishers, London and New York, 141–156.
3. Brown, J. F., B. D. Wardlow, T. Tadesse, et al., 2008: The vegetation drought response index (VegDRI): A new integrated approach for monitoring drought stress in vegetation. GISci. Remote Sens., 45, 16–46, doi: 10.2747/1548-1603.45.1.16.
4. Burton, I., R. W. Kates, and G. F. White, 1993: The Environment as Hazard. 2nd ed. The Guilford Press, New York, 284 pp.
5. Cai, Y., M. H. Song, Z. A. Qian, et al, 2015: Reanalyses of precipitation circulation and vapor transportation of severe dry and wet events in summer in arid region of Northwest China. Plateau Meteor, 34, 597–610. (in Chinese)