摘要：Combined with the inter-regional development of the Silk Road Economic Belt, the research into land degradation (LD)in areas of Central Asia(CA)will promote China's open development strategy to CA. The Mann-Kendalltrend test as well as the trend analysis was adopted to figure out the spatiotemporal characteristics of LD and drought in CA using data from the Standardized Precipitation Evapotranspira-tion Index(SPEI)together with the Normalized Dif ference Vegetation Index (NDV). Besides, the ef-fect of multi-time-scale SPEI on LD was analyzed. The results show that LD was mitigated from 1982 to 2015.It is found that about26.96%oftheregion's land area was significantly mitigated from LD.LD varies from 1982 to 1990,from 1990 to 2000,and from 2000 to 2015, with the most dramatic change occurring from 1990 to 2000.A marked difference is present between the annual SPEI and the seasonal SPEI trend. The spring SPEI has the largest change in trend. The annual SPEI and spring SPEI showed an upward trend,indicating that the CA shows a trand of becoming wet. In the remaining seasons, SPEI showed a slight downward trend or remained almost stable. From further analysis, it is demon-strated that there is a positive relationship between all multi-scale SPEI values and the NDVI trend as well as corresponding LD. The long-scale SPEI (SPEI3,6,12)was remarkably correlated with NDVI in most of the areas, while the short-scale SPEI(SPEIl)was not. In spring and summer, SPEI and NDVI had a more significant connection than they had in autumn and winter. The LD's response to multi-time-scale drought was highlighted in this paper so as to make predictions on LD and further enhance water efficiency in the study area.
关键词：Land degradation;drought;NDVI;SPEI;Central Asia
