Variabilité climatique et production cotonnière dans la commune de fianga au Tchad

Abstract

The issue of climate variability is one of the frequent challenges worldwide. This phenomenon poses a threat to the African population, especially in rural areas. The commune of Fianga has been facing climatic variations over the past few decades, disrupting agricultural activities. This study aims to assess the degree of influence of cotton production in response to rainfall and temperature variabilities in Fianga. The methodology is primarily based on a hypothetico-deductive approach. Secondary data collection involves documentary research on climatic data provided by DREM and ANADER, covering the period from 1981 to 2021, and cotton yield data also provided by ANADER for the same period. Primary data was collected using a questionnaire on a sample of 177 individuals (farmers and agro-pastoralists), derivedThe application of the Nicholson index yielded SPI values ranging from -0.71 to +2.2, indicating years of severe droughts (1982) and severe wet periods corresponding to flooding, notably in 2020. The Barakat index also showed that the years 1981, 1982, 1996, 2008, 2010, and 2012 were deficit years, whereas 1984, 1985, 1998, 1993, 2020, and 2007 were surplus years. The analysis of annual rainfall showed a trend towards stability but was also marked by disproportionate instability. This fluctuation in rainfall and temperature affects yields, with an average yield of 24 tons on 107 hectares per year, equivalent to 0.5 tons per hectare per year. The maximum monthly temperature is 39°C, and the minimum is 20°C. In addition to the adverse effects of rainfall and temperature variability, other factors such as low input use, lack of equipment, and soil infertility also contribute to the decline in yields in Fianga. This yield decline affects the agricultural income of more than 70% of farmers. To adapt, farmers in the area have employed several strategies, including modifying the agricultural calendar, diversifying income sources, using insecticides, and developing market gardening. These measures are supported by local elites and the state to identify and promote sustainable adaptation measures to rainfall and temperature variability in Fianga. from Nwana's formula (1982). The application of the Nicholson index yielded SPI values ranging from -0.71 to +2.2, indicating years of severe droughts (1982) and severe wet periods corresponding to flooding, notably in 2020. The Barakat index also showed that the years 1981, 1982, 1996, 2008, 2010, and 2012 were deficit years, whereas 1984, 1985, 1998, 1993, 2020, and 2007 were surplus years. The analysis of annual rainfall showed a trend towards stability but was also marked by disproportionate instability. This fluctuation in rainfall and temperature affects yields, with an average yield of 24 tons on 107 hectares per year, equivalent to 0.5 tons per hectare per year. The maximum monthly temperature is 39°C, and the minimum is 20°C. In addition to the adverse effects of rainfall and temperature variability, other factors such as low input use, lack of equipment, and soil infertility also contribute to the decline in yields in Fianga. This yield decline affects the agricultural income of more than 70% of farmers. To adapt, farmers in the area have employed several strategies, including modifying the agricultural calendar, diversifying income sources, using insecticides, and developing market gardening. These measures are supported by local elites and the state to identify and promote sustainable adaptation measures to rainfall and temperature variability in Fianga.