Sakellariou et al. (2026) Spatiotemporal Drought Assessment Projections for Climate-Resilient Planning in Distinct Mediterranean Agroecosystems

Identification

• Journal: Hydrology
• Year: 2026
• Date: 2026-02-15
• Authors: Stavros Sakellariou, Nicolas Dalezios, Marios Spiliotopoulos, Nikolaos Alpanakis, Στέργιος Κάρτσιος, Ioannis Faraslis, Georgios A. Tziatzios, Pantelis Sidiropoulos, Nicholas Dercas, Apostolos Tsiovoulos, Konstantina Giannousa, Alfonso Domínguez, José Antonio Martínez-López, R. López-Urrea, Fadi Karam, Hacib El Amami, Radhouan Nsiri
• DOI: 10.3390/hydrology13020073

Research Groups

• Department of Civil Engineering, University of Thessaly, Volos, Greece
• Department of Environmental Sciences, University of Thessaly, Larissa, Greece
• Department of Civil and Environmental Engineering, Brunel University of London, Uxbridge, UK
• Department of Meteorology and Climatology, School of Geology, Faculty of Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
• Laboratory of Hydraulic Works and Environmental Management, School of Rural and Surveying Engineering, Aristotle University of Thessaloniki, Thessaloniki, Greece
• Department of Natural Resources Management & Agricultural Engineering, Agricultural University of Athens, Athens, Greece
• Technical School of Agricultural and Forestry Engineering and Biotechnology, Regional Centre of Water Research (CREA), University of Castilla-La Mancha (UCLM), Albacete, Spain
• Desertification Research Centre (CIDE), CSIC-UV-GVA, Moncada, Valencia, Spain
• Department of Environmental Engineering, Faculty of Agriculture, Lebanese University, Beirut, Lebanon
• National Research Institute for Rural Engineering, Water, and Forestry (INRGREF), Ariana, Tunisia
• National Institute of Field Crops (INGC), Bousalem, Tunisia

Short Summary

This study provides long-term projections of drought and wetness conditions for three representative Mediterranean agroecosystems (Spain, Tunisia, Lebanon) to support climate-resilient planning. It reveals significant spatial variability in future drought and wetness extremes, with differing timings and intensities of driest and wettest hydrological years across regions, emphasizing the need for spatially targeted adaptation strategies.

Objective

• To explore the spatiotemporal projections of drought extremes in three distinct vulnerable Mediterranean regions (Eastern Mancha, Spain; Sidi Bouzid Governorate, Tunisia; Beqaa Valley, Lebanon) for climate-resilient planning.
• To provide a novel, spatially explicit, and comparative framework for assessing future drought and wetness extremes by integrating dynamically downscaled climate projections with pixel-based drought analysis.

Study Configuration

• Spatial Scale: Three distinct Mediterranean agroecosystems: Eastern Mancha (Spain, 8500 km²), Sidi Bouzid Governorate (Tunisia, 7405 km²), and the Beqaa Valley (Lebanon, approximately 120 km length and 16 km width). The Weather Research and Forecasting (WRF) model used a parent domain covering the broader Mediterranean basin with 18 km × 18 km horizontal resolution, and three one-way nested domains for each study region with 6 km × 6 km horizontal resolution. Precipitation output was remapped to a regular 5 km × 5 km grid.
• Temporal Scale: Future monthly precipitation projections for the period 2020–2050 (30 years). The hydrological year was defined as October to September. Historical drought/wetness assessment from 1980 to 2050 was extended.

Methodology and Data

• Models used:
  • Weather Research and Forecasting (WRF) model (version 4.2, Advanced Research WRF (ARW) core) for dynamic downscaling of future monthly precipitation.
  • Standardized Precipitation Index (SPI12) for quantifying drought and wetness severity at annual and monthly scales.
• Data sources:
  • CMIP5 CESM data under the RCP4.5 emissions scenario for forcing the WRF model.

Main Results

• Overall Trends: The study projects spatial variability and moderate temporal fluctuations in drought and wetness conditions across the three regions. Extreme drought events are not widely anticipated, but localized severe dry periods are expected.
• Driest Hydrological Years:
  • Spain (Eastern Mancha): Projected driest year in 2046–2047 (SPI = -1.24). Most of the area experiences moderate drought, with smaller areas in the northeast facing severe drought. Extreme drought conditions are projected from June to September.
  • Tunisia (Sidi Bouzid Governorate): Projected driest year in 2030–2031 (SPI = -1.44). The southeastern part is characterized by severe drought, while the northwestern region experiences moderate drought. Extreme drought is projected in the south from January to August.
  • Lebanon (Beqaa Valley): Projected driest year in 2047–2048 (SPI = -1.82). Most of the study area is characterized by severe drought, with the pilot study area predominantly experiencing extreme drought. Extreme drought conditions are projected from February to September.
• Wettest Hydrological Years:
  • Spain: Projected wettest year in 2045–2046 (SPI = 1.62). Central and southwestern parts show very wet conditions, with eastern Albacete experiencing extremely wet conditions.
  • Tunisia: Projected wettest year in 2045–2046 (SPI = 2.15). Most of the study area is expected to experience extremely wet conditions, with some regions showing very wet conditions.
  • Lebanon: Projected wettest year in 2028–2029 (SPI = 1.62). The pilot study area is expected to experience very wet conditions, while surrounding regions face moderately wet conditions.
• Decadal Patterns (2020-2048): The first projected decade (2020–2030) shows predominantly normal to slightly wet conditions. The following decade (2030–2040) is predicted to be mostly normal to slightly dry. The final decade (2040–2048) shows similar patterns for Spain and Lebanon, with more variability in Tunisia.

Contributions

• Extends previous historical drought/wetness assessments to future conditions up to 2050 for the studied Mediterranean regions.
• Provides a novel, spatially explicit, and comparative framework for assessing future drought and wetness extremes by combining dynamically downscaled WRF precipitation projections with pixel-based SPI analysis at a 5 km spatial resolution and across annual and monthly temporal scales.
• Offers an operational basis for informed, place-based resilience planning in Mediterranean agroecosystems, moving beyond descriptive drought assessment.
• Enables the identification of sub-regional variability in drought and wetness intensity, which is often masked in coarser or purely temporal analyses, thus underscoring the need for spatially targeted adaptation strategies.
• Identifies both driest and wettest projected years, enhancing preparedness, informing water-resource optimization, and supporting agricultural land-use planning.
• Recommends integrating drought projections into multi-hazard planning frameworks (e.g., drought and floods) to strengthen territorial resilience.

Funding

• SUPROMED project, Call 2018, under the PRIMA program of the European Commission (Grant Agreement No 1813).

Citation

@article{Sakellariou2026Spatiotemporal,
  author = {Sakellariou, Stavros and Dalezios, Nicolas and Spiliotopoulos, Marios and Alpanakis, Nikolaos and Κάρτσιος, Στέργιος and Faraslis, Ioannis and Tziatzios, Georgios A. and Sidiropoulos, Pantelis and Dercas, Nicholas and Tsiovoulos, Apostolos and Giannousa, Konstantina and Domínguez, Alfonso and Martínez-López, José Antonio and López-Urrea, R. and Karam, Fadi and Amami, Hacib El and Nsiri, Radhouan},
  title = {Spatiotemporal Drought Assessment Projections for Climate-Resilient Planning in Distinct Mediterranean Agroecosystems},
  journal = {Hydrology},
  year = {2026},
  doi = {10.3390/hydrology13020073},
  url = {https://doi.org/10.3390/hydrology13020073}
}