Centre for Environmental Management, University of the Free State, South Africa; Disaster Management Training and Education Centre for Africa, University of the Free State, South Africa; Department of Geography and Environmental Science, University of Fort Hare, Private Bag X1314, Alice, 5700, Eastern Cape Province, South Africa.
Disaster Management Training and Education Centre for Africa, University of the Free State, South Africa.
J Environ Manage. 2021 Apr 15;284:112028. doi: 10.1016/j.jenvman.2021.112028. Epub 2021 Feb 2.
Drought disaster is one of the major factors restricting the development of vegetation across a wide variety of environments. Monitoring the temporal and spatial dynamics of drought episodes in the study area is crucial for environmental and ecosystem conservation. This study assesses drought disaster by utilising space-based data and R programming for drought years 2003, 2007, 2012 and 2019 in the Free State Province, South Africa. Results revealed that the study area witnessed drought events in the year 2003 where March, August, September, October, November and December were more affected by drought disaster events. It was further observed that February and March were affected by extreme drought conditions in the year 2007. In year 2012, January, October, November and December, there exist moderate to severe drought conditions in the study area where some regions were more affected than the other. Finally, year 2019 witnessed variations in drought event distributions across the months with January, October and November witnessing severe to extreme drought conditions from about 0 to 30% drought values. Overall, this study shows that the 16-day Terra-MODIS composite and EVI products are sensitive to stressors associated with drought. The Vegetation Condition Monitoring Index (VCI) based on MODIS is suited for monitoring drought disasters. The technique used in this study revealed the suitability of MODIS data for assessing drought conditions and their potential environmental impacts.
干旱灾害是限制各种环境中植被发展的主要因素之一。监测研究区域干旱事件的时空动态对于环境和生态系统的保护至关重要。本研究利用基于空间的数据和 R 编程语言，评估了南非自由州省 2003 年、2007 年、2012 年和 2019 年的干旱灾害年份。结果表明，研究区域在 2003 年发生了干旱事件，其中 3 月、8 月、9 月、10 月、11 月和 12 月受干旱灾害事件的影响更为严重。还观察到 2007 年 2 月和 3 月受到极端干旱条件的影响。在 2012 年，1 月、10 月、11 月和 12 月，研究区域存在中度至重度干旱条件，一些地区比其他地区受到的影响更大。最后，2019 年，干旱事件分布在各个月份都存在变化，1 月、10 月和 11 月的干旱值从 0 到 30%之间，存在严重到极端干旱条件。总的来说，本研究表明，16 天 Terra-MODIS 合成和 EVI 产品对与干旱相关的胁迫因素敏感。基于 MODIS 的植被状况监测指数（VCI）适合监测干旱灾害。本研究中使用的技术揭示了 MODIS 数据在评估干旱条件及其潜在环境影响方面的适用性。
