Oukaddour, K.; Le Page, M.; Fakir, Y. Toward a Redefinition of Agricultural Drought Periods—A Case Study in a Mediterranean Semi-Arid Region. Remote Sens.2024, 16, 83.
Oukaddour, K.; Le Page, M.; Fakir, Y. Toward a Redefinition of Agricultural Drought Periods—A Case Study in a Mediterranean Semi-Arid Region. Remote Sens. 2024, 16, 83.
Oukaddour, K.; Le Page, M.; Fakir, Y. Toward a Redefinition of Agricultural Drought Periods—A Case Study in a Mediterranean Semi-Arid Region. Remote Sens.2024, 16, 83.
Oukaddour, K.; Le Page, M.; Fakir, Y. Toward a Redefinition of Agricultural Drought Periods—A Case Study in a Mediterranean Semi-Arid Region. Remote Sens. 2024, 16, 83.
Abstract
Drought is a powerful natural hazard that has significant effects on ecosystems amid the constant threats posed by climate change. This study investigates agricultural drought in a semi-arid Mediterranean basin through the interconnections of four indices: precipitation (meteorological reanalysis), vegetation development, thermal stress, and soil water deficit (remote sensing observations). The study focuses on the determination of agricultural drought periods. Firstly, the temporal connections between the various indices at different spatial scales and in different parts of the basin are investigated. Thereafter, a modified run-theory approach based on normality and dryness thresholds is applied. The Pearson correlations at different spatial scales showed a medium to low level of agreement between the indices, which was explained by the geographical heterogeneity and the climatic variability between the agrosystems within the basin. It is also shown that the cascade of impacts expected from lower precipitations is revealed by the cross-correlation analysis. The connection between precipitation deficit and vegetation remains significant for at least one month for most pairs of indices, especially during drought events, suggesting that agricultural drought spells can be connected in time through the three or four selected indices. Short-, mid-, and long-term impacts of precipitation deficiencies on soil moisture, vegetation, and temperature were revealed. As expected, the more instantaneous variables of soil moisture and surface temperature showed no lag with precipitation. Vegetation anomalies at the monthly time step showed a two-month lag with a preceding effect of vegetation to precipitation. Finally, the determination of drought events and stages with varying thresholds on the run-theory showed the large variability of duration, magnitude, and intensity according to the choice of both normality and dryness thresholds.
Keywords
Remote sensing; Run theory; Drought; Semi-arid
Subject
Environmental and Earth Sciences, Environmental Science
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
