Gómez-Gómez et al. (2025) Impact of climate change on droughts and their propagation in an alpine-semiarid basin in Granada, Spain. Does the snow component help to anticipate adaptation strategies?

Identification

• Journal: Journal of Hydrology Regional Studies
• Year: 2025
• Date: 2025-10-10
• Authors: Juan-de-Dios Gómez-Gómez, Antonio‐Juan Collados‐Lara, David Pulido‐Velazquez, Leticia Baena-Ruíz, Patricia Jimeno‐Sáez, Javier Senent‐Aparicio, Fernando Delgado-Ramos, Francisco Rueda-Valdivia
• DOI: 10.1016/j.ejrh.2025.102834

Research Groups

• Spanish Geological Survey (IGME), CSIC, Madrid, Spain
• Department of Civil Engineering, University of Granada, Water Institute, Granada, Spain
• University of Jaén, Department of Geology, Jaén, Spain
• Catholic University of San Antonio, Murcia, Spain
• Centro de Investigaciones sobre Desertificación (CIDE), CSIC-UV-GVA, Moncada, Valencia, Spain
• Water, Environmental and Agricultural Resources Economics (WEARE) Research Group, University of Córdoba, Spain

Short Summary

This study assesses past and projected climate change impacts on various drought types and their propagation in the Alto Genil Basin, an alpine Mediterranean region in southern Spain, with a focus on the role of snow in early adaptation strategies. Results indicate a significant temperature rise and precipitation decrease, leading to more frequent, severe, and prolonged droughts, particularly in snow-reliant areas, and a reduced lead time for operational drought response.

Objective

• To conduct a novel, integrated analysis of historical and potential future climate change impacts on meteorological, agricultural, hydrological, and operational droughts and their propagation in the Alto Genil Basin.
• To specifically examine the influence of the snow component on the early identification of adaptation strategies to mitigate operational droughts in this snow-dominated alpine Mediterranean catchment.

Study Configuration

• Spatial Scale: Alto Genil Basin, Granada, southern Spain (3241 km²), subdivided into 25 subbasins and aggregated into 10 homogeneous hydroclimatic areas.
• Temporal Scale:
  • Historical/Baseline: 1950–2005 (climate data), 1971–1995 (model calibration), 1995–2005 (model validation), 1976–2005 (drought analysis baseline).
  • Future: 2071–2100 (climate change scenarios).

Methodology and Data

• Models used:
  • Rainfall-runoff model: Téméz (1977)
  • Snowmelt model: Temperature-Index Snowmelt Model (TIM) based on a degree-day approximation
  • Crop water requirement model: CROPWAT (Allen et al., 1998)
  • Integrated management model: Aquatool (Andreu et al., 1996)
  • Drought assessment: Standardised Precipitation Index (SPI) approach (McKee et al., 1993) applied to precipitation, soil moisture, streamflow, and Demand Satisfaction Index (DSI) at a 12-month timescale.
  • Clustering: Agglomerative Hierarchical Clustering (AHC) for identifying homogeneous hydroclimatic areas.
• Data sources:
  • Historical precipitation and temperature: Spain02 project (Herrera et al., 2012).
  • Future precipitation and temperature: Regional Climate Model (RCM) simulations from the CORDEX project (2013) for the RCP8.5 concentration scenario, downscaled using bias correction and delta change techniques.
  • Flow data: Gauging stations in the Alto Genil Basin, complemented by the SIMPA model (Álvarez et al., 2005).
  • Urban demands: IGME-Junta de Andalucía study (2005).
  • Agricultural demands: Guadalquivir Hydrographic Confederation data.

Main Results

• Climate Projections (2071–2100 vs. 1950–2005): Mean annual precipitation is projected to decrease by approximately 27% (157.9 mm for E1, 154.6 mm for E2), while mean annual temperature is projected to increase by 6.6 °C for both future scenarios.
• Agricultural Water Demand: Agricultural water demand is projected to increase by 56.9 hm³/year (+23%) under scenario E1 and 55.6 hm³/year (+22.5%) under scenario E2.
• Water Availability and Hydrology: A generalized reduction in runoff is projected across all hydroclimatic areas. In snow-dominated areas, peak flows are expected to shift from April–June to February–March (E1) or January–March (E2) due to reduced snowfall and a transition to a rainfall-dominated regime.
• Drought Dynamics:
  • Meteorological, agricultural, and hydrological droughts are projected to become more frequent, severe, and prolonged, with the most significant impacts observed in snow-reliant subbasins.
  • Operational droughts show the most adverse impacts, particularly in high-demand hydroclimatic areas (HCAs 3, 6, and 8). Additional groundwater pumping restrictions (LP scenarios) further exacerbate operational drought effects.
• Drought Propagation and Response Time: The time lag for maximum correlation between meteorological and operational droughts is projected to decrease from 7 months historically to 6 months in the future (LPE1E2 scenario) for both the entire Alto Genil Basin and the Canales subbasin (HCA 2).
• Vulnerability of Snow-Fed Systems: The correlation between meteorological and operational droughts is projected to increase (R² from 0.41 to 0.67 for the basin, and 0.26 to 0.42 for Canales subbasin), indicating a reduced buffering capacity of the snow component and heightened vulnerability of snow-fed systems to climate change.

Contributions

• Provides a novel, integrated assessment of climate change impacts on multiple drought types (meteorological, agricultural, hydrological, operational) and their propagation in an alpine Mediterranean basin with a significant snow component.
• Quantifies the influence of the snow component on the timing of operational drought onset, demonstrating a reduced lead time for adaptation strategies.
• Highlights the increased vulnerability of snow-fed systems to climate change, showing a shift from snow to rain regimes and a diminished regulatory function of snowpack.
• Offers concrete insights for policymakers and water resource managers to advance drought response timing, strengthen early warning systems, reinforce storage, prioritize high-risk areas, and adopt scenario-based planning, complemented by a bottom-up approach.

Funding

• STAGES-IPCC (TED2021–130744BC21/AEI/10.13039/501100011033/Unión Europea NextGenerationEU/PRTR)
• SIGLO-PRO (PID2021–128021OB-I00/AEI/10.13039/501100011033/FEDER, UE)
• SER-PM (2908/22; Organismo Autónomo Parques Nacionales) from the National Park Research Program.

Citation

@article{GómezGómez2025Impact,
  author = {Gómez-Gómez, Juan-de-Dios and Collados‐Lara, Antonio‐Juan and Pulido‐Velazquez, David and Baena-Ruíz, Leticia and Jimeno‐Sáez, Patricia and Senent‐Aparicio, Javier and Delgado-Ramos, Fernando and Rueda-Valdivia, Francisco},
  title = {Impact of climate change on droughts and their propagation in an alpine-semiarid basin in Granada, Spain. Does the snow component help to anticipate adaptation strategies?},
  journal = {Journal of Hydrology Regional Studies},
  year = {2025},
  doi = {10.1016/j.ejrh.2025.102834},
  url = {https://doi.org/10.1016/j.ejrh.2025.102834}
}