2001—2018年中亚干旱区地表水资源时空变化特征

Spatio-temporal Dynamic Characteristics of Surface Water Resources in Arid Regions of Central Asia From 2001 to 2018

基于2001—2018年长时间序列地表水遥感监测数据,提取中亚五国地表水面积信息,通过动态度法、变化斜率法和相关分析法揭示中亚五国地表水面积的时空动态变化特征并对其进行驱动力分析。结果表明:(1)中亚五国地表水呈"北密南疏"分布特征,中北部地表水变化明显。近18 a来,季节水面积呈显著增加趋势,增加了133.55%,而永久水呈波动减少趋势,减少了17.27%。哈萨克斯坦地表水面积占比最大且变化也最为明显,其次是乌兹别克斯坦,其余三国无较大变化。(2) 2001—2018年,中亚五国全区季节水动态度为7.42%,并呈快-慢-快的增长趋势,而永久水呈增长-下降-增长的演变趋势,乌兹别克斯坦地表水变化最为活跃;北部边缘及图尔盖洼地、西部里海沿岸和咸海地区永久水面积显著减少而季节水显著增加,永久水向季节水转换现象明显。(3)中亚五国增温趋势不明显,降水呈减少趋势,人口、GDP和耕地均呈增加趋势。中亚五国地表水面积变化主要受社会经济因子的影响,气候因子对地表水的影响不显著。

Based on long-time series of surface water remote sensing monitoring data from 2001 to 2018, the information of surface water area in the five countries of Central Asia was extracted. We revealed the spatiotemporal features and driving force of their surface water area dynamics using the dynamic degree index, the slope analysis method, and correlation analysis method. The results show that: 1) The spatial distribution characteristics of the surface water of the study area were “dense in the north and sparse in the south”, and the surface water had an obvious change in the central and northern areas. In the past 18 years, the area of seasonal water increasing by 133.55%, while the area of permanent water showed a fluctuating decrease by 17.27%. The largest proportional area of surface water was Kazakhstan with the most obvious changes, followed by Uzbekistan. The surface water of the other three countries had no evident change. 2) From 2001 to 2018, the dynamic degree index of seasonal water areas in five Central Asian countries was the largest value by 7.42% and showed a fast-slow-fast growth trend. In contrast, permanent water showed a growth-decline-growth evolution trend. The dynamic degree index of the surface water area of Uzbekistan was a maximum than other countries.The area of permanent water significantly decreased in the northern edge and Turgai Depression, the Caspian Sea of the western coast, and the Aral Sea, while that the area of the seasonal water significantly increased. The permanent water conversion to seasonal water was evident in those areas. 3) The increasing trend of temperature in the five Central Asian countries was not evident, while the precipitation decreased. The population,GDP, and cultivated land were increasing. The area changes of surface water of the five Central Asian countries were mainly affected by social and economic factors, while the impact of climate factors on surface water was not significant.