College of Water Resources and Architectural Engineering, Northwest Agriculture and Forestry University, Yangling, Shaanxi 712100, China; Institute of Water Saving Agriculture in Arid Areas of China, Northwest Agriculture and Forestry University, Yangling, Shaanxi 712100, China.
College of Water Resources and Architectural Engineering, Northwest Agriculture and Forestry University, Yangling, Shaanxi 712100, China; Institute of Water Saving Agriculture in Arid Areas of China, Northwest Agriculture and Forestry University, Yangling, Shaanxi 712100, China.
Sci Total Environ. 2018 Oct 15;639:1015-1027. doi: 10.1016/j.scitotenv.2018.05.243. Epub 2018 May 26.
The accuracy of gauge-measured precipitation (P) affects drought assessment since drought severity changes due to precipitation bias correction. This research investigates how drought severity changes as the result of bias-corrected precipitation (P) using the Erinc's index I and standardized precipitation evapotranspiration index (SPEI). Daily and monthly P values at 552 sites in China were determined using daily P and wind speed and air temperature data over 1961-2015. P-based I values were generally larger than P-based I for most sub-regions in China. The increased P and P-based I values indicated wetter climate conditions than previously reported for China. After precipitation bias-correction, Climate types changed, e.g., 20 sites from severe-arid to arid, and 11 sites from arid to semi-arid. However, the changes in SPEI were not that obvious due to precipitation bias correction because the standardized index SPEI removed the effects of mean precipitation values. In conclusion, precipitation bias in different sub-regions of China changed the spatial and temporal characteristics of drought assessment.
测量的降水量（P）的准确性会影响干旱评估，因为降水偏差修正会改变干旱严重程度。本研究使用 Erinc 指数 I 和标准化降水蒸散指数（SPEI），调查了由于降水量（P）的偏差修正，干旱严重程度会如何变化。利用 1961 年至 2015 年期间每天的降水量和风速及气温数据，确定了中国 552 个站点的日降水量和月降水量。在中国的大多数次区域，基于降水量的 I 值普遍大于基于实测降水量的 I 值。增加的降水量和基于降水量的 I 值表明，中国的气候条件比之前报道的更加湿润。在对降水量进行偏差修正后，气候类型发生了变化，例如，有 20 个站点从重度干旱变为干旱，11 个站点从干旱变为半干旱。然而，由于降水量的标准化指数 SPEI 去除了平均降水量值的影响，因此 SPEI 的变化并不明显。总之，中国不同次区域的降水量偏差改变了干旱评估的时空特征。
