Abhatoo - Centre Nationale de Documentation

The agriculture in dryland areas is inherently sensitive to climate conditions, and is among the most vulnerable sectors to the risks and impacts of global climate change. The objective of this study is to characterize drought periods and severity, rainfall patterns and the evolution of length of growth period in the arid dryland Ahmar area plain of Morocco. The climate data covers the last forty-three years period (1975-2017). The National Department of Meteorology (DMN) for Echemmaia climatic station provided them. Results of this study show a significant decline of the annual rainfall from 252.9 mm/year to 184.4 mm/year during the last 43 years. The Standardized Precipitation Index indicate that dry years are prevailing during the las 20 years with 80% of the years are either normal to moderately dry years or dry years (20%). The aridity Martonne index demonstrate a clear shift of climate from arid to hyper-arid in the study area. The length of growth period decreased from 125 days to only 95 days. The year 1996 is the break point for all these calculated indices. In conclusion, the rainfall pattern in the dryland area of Ahmar plain of Morocco is decreasing and becoming scares and erratic affecting therefore crop production and stability.