Climatic Variability and Agricultural Season: Analysis of the Evolution of Essential Agroclimatic Parameters in Central East Cote D’ivoire

Agriculture is no longer the main source of money income in many rural areas of West Africa owing to the low agricultural productivity due to climatic hazards. Even with the gradual return of rainfall, it is probable that this trend will continue. Climatic hazards are areal concern for all West African countries owing to their adverse socio-economic and environmental effects. Interannual fluctuations in rainfall represent the main climatic hazard for West African countries such as Côte d'Ivoire, whose economy is principally based on agriculture [1]. This is of the pluvial type, i.e. dependent on rain, which is the most variable climatic element. The decline in rainfall that began in the Gulf of Guinea countries at the end of the 1970s, became more intense in Côte d'Ivoire during the 1980s and 1990s before experiencing a certain remission during the 2000s [2,10]. Thus, these rainfall recessions induce variability in agricultural calendars through the variation of start and end dates, as well as the duration of the seasons [3,9]. Therefore, the fundamental question that emanates from these observations is the following: what are the variations of the major agroclimatic parameters in the Center-East of Côte d'Ivoire? Thus, this study aims to show the modifications of the major agroclimatic parameters of the agricultural calendars in the Center-East of Côte d'Ivoire between 1971 and 2020. Once prosperous and a major center of rural immigration, the east-central part of Côte d'Ivoire has experienced an inversion of the situation in recent years, which has made it an important center of emigration. The decline in planting activity can be observed both in terms of areas and in terms of production [4,9]. In recent decades, the Center-East of Côte d'Ivoire has suffered a drop in rainfall marked by droughts [5,10]. The economic consequences of such climatic and ecological changes are dramatic in this region mainly oriented towards farming [6]. The irregularity of the temporal distributions of precipitations and the heterogeneity of their spatial distribution constitute today the essential characteristics of the pluviometry of this region. The analysis of rainfall over the three sub-periods 1971-2000, 1981-2010 and 1991-2020 shows that agriculture has been going through a rainfall crisis for five decades now. The typical aspects of rainfall variability are its persistence and amplitude [7]. The impact of this phenomenon has been observed through the drying up of the majority of water points, the rotting of seedlings, a reduction in arable land, lower yields and the resurgence of diseases (human, plant and animal). .Thus, entire regions have become more vulnerable than in the past, thus weakening their agricultural future and accentuating the process of deforestation [8]. In addition, this has imposed on them transformations in their lifestyles, regardless of the economic sector considered [9,7]. These characteristics give the climate a determining role in the development of the agricultural season and in agricultural production. Thus, given their immediate and lasting repercussions on agriculture and on humans. This variability leads to great uncertainty on the date of sowing which, on the same site, can occur over a period of nearly two months depending on the onset of the rains [10]. Our interest as a geographer aims to assess the extent of the evolution of rainfall in the Center-East in order to reveal its influence on the agricultural season. In agriculture, it has been shown that farmers who are convinced of the existence of climate variability have better capacities to manage risk and change. They are likely to anticipate it, learn and organize themselves and they are more willing to modify their systems [8,9]. Hence, an understanding of this climatic phenomenon could at least help to program interventions aimed at stabilizing and increasing yields [11].