Assessment of drought frequency, severity, and duration and its impacts on vegetation greenness and agriculture production in Mediterranean dryland: A case study in Tunisia
Assessment of drought frequency, severity, and duration and its impacts on vegetation greenness and agriculture production in Mediterranean dryland: A case study in Tunisia
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DOI：
10.1007/s11069-020-04422-w
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发表时间：
2020-11
期刊：
影响因子：
3.7
通讯作者：
Nada Ben Mhenni;M. Shinoda;B. Nandintsetseg
中科院分区：
文献类型：
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作者：
Nada Ben Mhenni;M. Shinoda;B. Nandintsetseg
在气候变暖的情况下，干旱是影响世界各地旱地的最严重的自然灾害之一。地中海区域，包括突尼斯，预计将经历全球最主要的干旱趋势。然而，对突尼斯干旱的详细区域尺度研究有限，妨碍了对干旱对生态系统和社会影响的评估。利用气象干旱指数和土壤水分干旱指数，研究了1982-2011年突尼斯三个植被带的干旱特征及其对植被绿度和农业生产力的影响，并确定了最适合每个植被带的干旱指数。结果表明：气象干旱时间短、频率高，引发土壤水分干旱时间长、强度大；标准化降水指数是北部森林植被和农业干旱的最佳指标，而Palmer干旱严重程度指数在中部草原和南部沙漠（南部沙漠无作物数据）中是最好的。滞后相关分析表明，与其他地区相比，中部草原植被绿度和小麦产量对干旱的响应更为明显，且显著滞后时间更长。这些结果表明，根系较浅的耕地物种（中部草原和南部沙漠）与根系较深的森林物种（北部森林）相比，对降雨变化的响应速度更快，而森林物种（北部森林）根系较深，能够提供充足的水分。这里确定的特定区域指数将为突尼斯监测和缓解干旱提供有用的措施。
Drought is among the highest-impact natural hazards affecting drylands around the world in a warming climate. The Mediterranean region, including Tunisia, is projected to experience the most predominant drying trends worldwide. However, a detailed regional scale study of drought for Tunisia has been limited, hampering an assessment of drought impact on the ecosystem and society. This study explored drought characteristics and its effect on vegetation greenness and agricultural productivity in three vegetation zones of Tunisia during 1982–2011, taking advantage of both meteorological and soil moisture drought indices and identifying the most appropriate index for each zone. The results revealed that meteorological droughts were short and frequent, triggering soil moisture droughts that were long-lasting and intense. The standardized precipitation index was identified as the best indicator of vegetation and agricultural droughts in the Northern forest, while the Palmer Drought Severity Index was best in the Central steppe and Southern desert (no crop data in the Southern desert). The lag-correlation analysis revealed that the response of both vegetation greenness and wheat productivity to droughts was more pronounced and had a longer significant lag in the Central steppe than in the other regions. These results suggest that arable land species (Central steppe and Southern desert), characterized by shallow roots, have a rapid response to rainfall variability when compared with forest species (Northern forest), which have deep roots allowing them an adequate supply of moisture. The region-specific indices identified here will provide a useful measure for drought monitoring and mitigation in Tunisia.