Department of Geosciences, Texas Tech University, Lubbock, TX 79409, USA.
Department of Geological Sciences, University of Texas at El Paso, El Paso, TX 79968, USA.
Sci Total Environ. 2021 Feb 10;755(Pt 1):142461. doi: 10.1016/j.scitotenv.2020.142461. Epub 2020 Sep 24.
Exploring the effects of drought and land use/land cover (LULC) on aeolian dust emission is important to enhance dust models to account for anthropogenic land surface change. Hitherto, there has been no systematic effort to quantitatively estimate associations between LULC and drought with the number of dust point sources as a surrogate for emission on both local and global levels. Previously, we created a dataset of dust emission point sources in the southwestern United States (U.S.) during the years 2001-2016, including a period of extreme drought. However, that work did not investigate the effects of drought on the detected dust point sources. Here, we used that dataset to test the hypothesis that there is a statistically significant association between drought level and LULC that may contribute to the number of dust point sources in the Southern Great Plains and Chihuahuan Desert regions of the U.S. The spatio-temporal analysis showed that the geographic mean center for all the dust points, as well as the majority of the annual geographic mean centers between 2001 and 2016, is located in the Southern High Plains. Areas suffering from severe to exceptional drought tend to attract the annual geographic mean center of dust points. The chi-square analysis results showed a significant association between land cover type (as defined in the National Land Cover Database) and drought level with the number of dust point sources (χ (6) = 45.54, р < 0.001), thus supporting the proposed hypothesis. Results from this study indicate that human activities in dust-prone regions have clear potential to worsen the negative impacts of drought by changing LULC and increasing erodibility in multiple ways. This study paves the way for future efforts that can utilize more data and conduct more robust statistical analysis of the drought-LULC-dust linkage on both regional and global scales.
探索干旱和土地利用/土地覆盖（LULC）对风沙尘排放的影响对于增强粉尘模型以考虑人为土地表面变化非常重要。迄今为止，尚无系统的努力来定量估计 LULC 与干旱与粉尘点源数量之间的关联，粉尘点源数量可以作为当地和全球水平排放的替代指标。此前，我们创建了美国西南部（美国）2001-2016 年期间粉尘排放点源数据集，其中包括一段极端干旱时期。然而，该研究并未调查干旱对检测到的粉尘点源的影响。在这里，我们使用该数据集来检验以下假设：干旱程度与 LULC 之间存在统计学上显著的关联，这可能导致美国大平原南部和奇瓦瓦沙漠地区的粉尘点源数量增加。时空分析表明，所有粉尘点的地理平均中心，以及 2001 年至 2016 年之间的大多数年度地理平均中心，都位于大平原南部。遭受严重至异常干旱的地区往往会吸引年度地理平均粉尘点中心。卡方分析结果表明，土地覆盖类型（国家土地覆盖数据库中定义）与干旱程度与粉尘点源数量之间存在显著关联（χ（6）= 45.54，р < 0.001），从而支持了所提出的假设。本研究结果表明，在粉尘多发地区，人类活动通过多种方式改变土地利用/土地覆盖和增加可蚀性，有可能加剧干旱的负面影响。本研究为未来在区域和全球范围内利用更多数据并对干旱-LULC-粉尘联系进行更稳健的统计分析铺平了道路。
