Retrospective Analysis and Future Projections of Bioclimatic Indices Under Climate Change: The Case of Azilal Province, Morocco

¹ National School of Forest Engineers (ENFI), Salé, Morocco
² Mohammed V University in Rabat (UM5R), Rabat, Morocco

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

We examine the bioclimatic changes, water balance and thermal extremes in Azilal Province, Morocco using a combination of historical daily temperature and precipitation records (1983-2016) and downscaled climate model intercomparison projections (CMTP6) (2015-2100) in the context of SSP2-4.5 and SSP5-8.5. Over the period 1983-2016, mean annual temperature increases by +1 °C (faster for Tmax (+0.44 °C decade⁻¹) than for Tmin (+0.30 °C decade⁻¹)). Annual precipitation is highly variable and does not show any significant trend, yet the future trend projected is a median 20-30% decrease by 2100 for SSP5-8.5. Moisture Diagnostics show a trend of increasing aridity CMI & SPEI show a strengthening climatic water deficit CMI < -1.5m year⁻¹ by 2100 for SSP5-8.5. Heat extremes increase in strength (days > 35 °C +13.8% per decade) and there is an increase in drought frequency in projections mainly due to increasing evaporative demand. A clustering based on the regimes "Wet/DTR↓" and "Dry/DTR↑" is identified with the regime of "Dry/DTR↑" increasing to 50-60% f the province by 2100 under SSP5-8.5. The combined signal brings up the issue of rising exposure to heat and water scarcity.