基于TRMM降水数据的1998-2015年'一带一路'干旱时空分布

摘要

干旱是一种世界范围的自然灾害,长期影响各国农业生产和社会经济活动."一带一路"沿线区域生态环境脆弱、农业耕地集中、干旱灾害频繁,利用遥感卫星监测大区域的干旱水平及其时空变化,对于科学掌握"一带一路"地区的干旱格局、区域分异特征,及其对农业耕地的影响具有重要的科学和现实意义.本文基于TRMM降水数据,利用降水距平百分率干旱模型研究和获取了N50°以南的"一带一路"沿线地区1998-2015年逐月干旱时空分布,得知冬季的干旱主要分布在东北亚、东南亚和南亚地区,夏季的干旱主要分布在中亚和西亚地区,干旱的发生具有明显的季节周期性.利用BFAST算法以经济走廊为骨干划分六大片区分析了"一带一路"地区干旱的区域分异特征,可知18年来,东北亚、西亚北非、南亚和中东欧地区的干旱平均水平呈现小范围的减轻趋势,中亚地区的干旱平均水平呈现小范围的增强趋势,东南亚地区的干旱平均水平变化呈现先减后增的波动特征.1998-2015年间"一带一路"地区的干旱总面积以每年40260 km2的总趋势不断减少.%Drought is a worldwide natural disaster that has long affected agricultural production as wel as social and economic activities. Frequent droughts have been observed in the Belt and Road area, in which much of the agricultural land is concentrated in fragile ecological environment. Based on the Tropical Rainfal Measuring Mis-sion Satelite (TRMM) 3B43 precipitation data, we used the Precipitation Abnormity Percentage drought model to study the monthly spatio-temporal distribution of drought in south region of N50° of the Belt and Road area. It was observed that drought during winter was mainly distributed in Northeast Asia, Southeast Asia, and South Asia, while it was mainly distributed in Central Asia and West Asia during summer. The occurrence of historical droughts indi-cates an obvious seasonal cycle. The regional variations in drought were analyzed using the Breaks for Additive Season and Trend tool (BFAST) in six sub-regionsaccording to the spatial distribution of six economic corridors in the Belt and Road area. The average drought conditions over the 18 years show a slight decreasing trend in Northeast Asia, West Asia, North Africa, South Asia, Central and Eastern Europe, and a slight increasing trend in Central Asia. However, it was a fluctuating pattern of first increasing and then decreasing in Southeast Asia. The results indicate that the total drought area in the Belt and Road region showed a general decreasing trend at a rate of 40,260 km2 per year from 1998 to 2015.