An observational analysis of precipitation and deforestation age in the Brazilian Legal Amazon
An observational analysis of precipitation and deforestation age in the Brazilian Legal Amazon
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DOI：
10.1016/j.atmosres.2022.106122
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发表时间：
2022-03
影响因子：
5.5
通讯作者：
Ye Mu;C. Jones
中科院分区：
文献类型：
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作者：
Ye Mu;C. Jones
亚马逊河流域的降雨在多个时空尺度上受到大气环流动力学的影响。人类活动的影响，如森林砍伐、土地使用变化和全球气候变化，也是决定南美洲降雨量的关键因素。模拟研究预测，随着亚马逊森林的不断砍伐，气候将更加干燥，但对降雨量和森林砍伐模式的变化的观测评估有限。本研究分析了1981年至2020年降雨量的时空趋势，并与巴西法律的亚马逊（BLA）森林砍伐年龄的关系。改进的降雨数据集是通过校准气候灾害组红外降水站（CHIRPS）数据与观测从BLA的雨量计网络。趋势分析，以确定在BLA降水的显着变化。基于卫星的土地覆盖数据Maplets和ET数据集被用来评估类似的趋势。虽然观察到很大的空间变异性，但结果表明，旱季负降雨量趋势和老年砍伐森林地区之间存在一致的关系。砍伐森林长达十年，增加了降雨量，砍伐森林时间较长的地区减少了旱季的降雨量。这些结果表明，在水文气候的BLA和未来的土地覆盖变化的脆弱性增加的重大变化。
Rainfall in the Amazon is influenced by atmospheric circulation dynamics on multiple spatiotemporal scales. Anthropogenic influences such as deforestation, land-use changes, and global climate change are also critical factors in determining rainfall in South America. Modeling studies have projected a drier climate with the ongoing deforestation in the Amazon, but observational evaluation of the variability of rainfall and deforestation patterns has been limited. This study analyzes spatiotemporal trends in rainfall between 1981 and 2020 and relationships with deforestation age in the Brazilian Legal Amazon (BLA). An improved rainfall dataset is derived by calibrating the Climate Hazards Group Infrared Precipitation with Stations (CHIRPS) data with observations from a rain gauge network in the BLA. Trend analysis is employed to identify significant changes in precipitation over the BLA. Satellite-based land cover data Mapbiomas and ET datasets are used to evaluate similar trends. While large spatial variability is observed, the results show coherent relationships between negative dry-season rainfall trends and old-age deforested areas. Deforestation aged up to a decade enhanced rainfall and older deforested regions have reduced rainfall during the dry season. These results suggest substantial changes in the hydroclimate of the BLA and increased vulnerability to future land cover change.