Institute of Water and Environmental Management, Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen, Böszörményi 138, 4032 Debrecen, Hungary.
Department of Civil Engineering, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia.
Int J Environ Res Public Health. 2022 Dec 8;19(24):16469. doi: 10.3390/ijerph192416469.
Drought is one of the natural hazards that have negatively affected the agricultural sector worldwide. The aims of this study were to track drought characteristics (duration (DD), severity (DS), and frequency (DF)) in South Africa between 2002 and 2021 and to evaluate its impact on wheat production. Climate data were collected from the South African Weather Service (SAWS) along with wheat yield data from the Department of Agriculture, Forestry and Fisheries (2002-2021). The standard precipitation index (SPI) was calculated on 3-, 6-, 9-, and 12-month time scales, and the trend was then tracked using the Mann-Kendall (MK) test. To signify the climatic effects on crop yield, the standardized yield residual series (SYRS) was computed along with the crop-drought resilience factor (CR) on a provincial scale (2002-2021). The output of the SPI analysis for 32 stations covering all of South Africa indicates a drought tendency across the country. On a regional scale, western coastal provinces (WES-C and NR-C) have been more vulnerable to meteorological droughts over the past 20 years. Positive correlation results between SYRS and wheat yield indicate that the WES-C province was highly influenced by drought during all stages of wheat growth (Apr-Nov). Historical drought spells in 2003, 2009, and 2010 with low CR = 0.64 caused the province to be highly impacted by the negative impacts of droughts on yield loss. Overall, drought events have historically impacted the western part of the country and dominated in the coastal area. Thus, mitigation plans should be commenced, and priority should be given to this region. These findings can assist policymakers in budgeting for irrigation demand in rainfed agricultural regions.
干旱是影响全球农业部门的自然灾害之一。本研究的目的是追踪 2002 年至 2021 年期间南非的干旱特征（持续时间（DD）、严重程度（DS）和频率（DF）），并评估其对小麦生产的影响。气候数据来自南非气象局（SAWS），小麦产量数据来自农业、林业和渔业部（2002-2021 年）。标准降水指数（SPI）在 3、6、9 和 12 个月的时间尺度上进行计算，然后使用 Mann-Kendall（MK）检验跟踪趋势。为了表示气候对作物产量的影响，在省级尺度（2002-2021 年）上计算了标准化产量残差序列（SYRS）和作物干旱恢复力因子（CR）。覆盖南非所有地区的 32 个站的 SPI 分析结果表明，该国各地都存在干旱趋势。在区域尺度上，过去 20 年来，西部沿海省份（WES-C 和 NR-C）更容易受到气象干旱的影响。SYRS 和小麦产量之间的正相关结果表明，在小麦生长的所有阶段（4 月至 11 月），WES-C 省都受到干旱的严重影响。2003 年、2009 年和 2010 年历史干旱时期的 CR = 0.64 较低，导致该省受到干旱对产量损失的负面影响的高度影响。总体而言，干旱事件历史上影响了该国的西部地区，在沿海地区占主导地位。因此，应开始制定缓解计划，并优先考虑该地区。这些发现可以帮助决策者为雨养农业地区的灌溉需求预算。
