CLIMATE CHANGE CHARACTERIZATION IN THE SEMI-ARID ABDA PLAIN IN WESTERN CENTRAL MOROCCO

The Abda plain is part of the semi-arid areas of Morocco, which are subject to the effects of climate change. Agricultural activities are strongly affected by the repeated droughts in this part of Morocco. There is need for an agro-climatic characterization in order to better help farmers adapt. The objective of this work is to study the evolution pattern and to characterize agro-climatic tendencies in the dryland area of Abda, plain of Morocco. Results of this study show a continuous and significant decline of the total amount of rainfall received by this area, with 108 mm rainfall decrease over the last 43 years. The average Martonne index calculated during the two distinct period 1975-1996 and 1997-2017 are, respectively 13.9 and 9.4. Indeed, the Standardized Precipitation Index calculated confirm the tendency of droughts period with about 71%, the years were normal and that 29 % were moderately or severe dry years but no wet years during the last two decades. For the length of growth period, a decrease reported during the two last 20 years with a decline from 192 days during the first period to only 138 days during the second period. The year 1996 is the break point for all calculated average indices. In conclusion, this work shows that the rainfall pattern in the dryland area of Abda, plain of Morocco is decreasing with erratic rainfall, high frequencies of severe droughts and reduced crop growth period.